I see someone suggested the stock carb settings... next you need a bigger air filter. What you have is restricting the airflow into the carb at higher RPMs so you are running rich at high RPM. That's why it was running great when you didn't have the air cleaner on it. What you are using looks like it's got about a third the filter area you need.
My knee jerk reaction after working on a number of 2-cycles (Snowmobiles) when I was younger when you installed that air filter was, "That's gonna starve it of air." (Especially when you foreshadowed that there was power problems) Temporarily try it without the air filter? Like has been suggested, use a larger air filter? Mike Patey it and make a carbon fiber air intake that forces air into the filter and actually flies the airplane while you have a rum and coke...
Anytime you're dealing with a carb, first step is to verify the float (fuel) level is at the specified point. That affects the jetting and you'll be chasing your tail till it's right. You can put a clear fuel tube on the bowl drain, run it up above the carb and see where the fuel level is sitting inside. It sounds to me like it's not getting enough fuel. I wonder if that fuel pump is keeping up at full power? Watching the fuel level in the bowl while it's running will tell you for sure.
You’re referring to pop-off pressure of the float bowl needle valve. This can be checked with a pressure gauge and set with the appropriate spring tension. No need to see the level in the float bowl, just verify it opens and closes at the correct pressure and the fuel will be where it should.
With Rotax 2-strokes you should always use the stock jets, needles, and carb. You adjust prop pitch and Length to achieve Rotax’s rpm, egt, and cht parameters. If too much prop it will running rich, Cht will be high, EGT will be low, and it will not reach max rpm. If so you take out pitch or shorten blades. If too little prop you’ll see low CHT, high EGT, and too high of rpm. Then you should add more pitch or length. also run the proper air filter. Also found too soft of a fuel line from tank to pump can cause the fuel pump to lose suction.
Totally correct. A friend runs these engines in racing hovercraft. Start at factory settings & fine tune with an EGT. An EGT gauge is worth having in the cabin - you can see potential seizures before they happen.
Used to tune, ride and race a 350cc 2 stroke motorcycle. You have a 447 twin and that air filter looks waaay too small, especially for feeding 2 cylinders. The consequence would be restricting airflow more and more as rpms increase, leading to increasingly rich mixture and bogging. My 350 twin had 2 filters on 2 carbs that each were at least 4 times the size of yours. Your original engine testing and break-in showed no air filter--a huge difference in the very sensitive 2 stroke engines. Love your bringing this air-bike back to life!!
Try the factory Jets/ Settings.. 165 Main, 45 pilot, needle clip 2 down from top, air screw .5 turn out from closed. I have the same engine in my Firefly and it runs great with the factory settings. Plugs will tell you if it's rich or lean. Cool plane!
@@siiilvija1 I wish! Born and raised here in Michigan. I enjoyed your Lithuania videos. Cool to see my homeland for first time! You guys make great videos! Jonas is one of my favs to watch! Keep up the good work.
After watching your video I then read all the comments. Jonas, you have some great fans who really seem to know their stuff. Watching you and Silvija is an adventure unto itself.
Cool video. If you haven't figured it out yet, here's the fix: Drain the fuel and put it in your pickup. Get fresh fuel and 50:1 synthetic 2-stroke. Return all carb settings to factory setting. Anchor rear of plane using rope, start engine and do warm-up/run-up. Untie rope and fly away.
Two strokes, man, always a pain. Motocrossed two strokes for years, constant upkeep and re-jetting. Occasionally a seize up and rebuild! Fun stuff! Also, love the ads! You guys are great.
Love seeing you get that bird up (even for just a second). I will commend you on your in video sponsorship ads. They are one of the only ones that I actually enjoy watching. Keep it up.
Hi Jonas ans Silvia, as far as I can see your carburator has bien wrongly reassembled. The clip maintaining the needle must be placed underneath the white plastic part and not over. Don't forget to get back to the good settings of jets and needle then before next run up. Good Luck Jean-Luc from France
Sounds to me like it's running the bowl dry. You'll need to raise the fuel level in the bowls by bending the tab on the floats so that they're higher in the bowl. That's if the pump is working correctly, and any fuel filters and lines are free flowing and unobstructed. Sounded like it was running rough on the runway, but after hearing it from Silvija's video, it sounded fine - the wind noise was distorting the sound. Made some great progress on that, Jonas! Great to see that thing flying at the end there! Looks like so much fun! I can't seem to get a day with light winds out here in the Northeast for the paramotor - every day is either freezing cold, howling winds, or raining. I can't wait for summer! I want to move to FL, but I can't convince my wife of that idea, sadly. Some day! Tired of this cold crap! Maybe I'll burn some tires to speed up this global warming thing. 😂
The EGT is your tuning tool but that reading will be inaccurate if the fuel supply isn't keeping up but the color on the plugs tells the ultimate story. For the thing to actually die under power, that indicates it has a fuel supply issue.
Not true. Rotax has designed the jetting for a filter. No filter is asking for trouble so keep you self proclaimed expert advice to yourself. BTW. K&N air filters are the least restrictive on the market (if properly maintained). EGT tells all.
I put one of those “high performance” filters on a little dirt bike and couldn’t ever get it to run right consistently. went back to the stock foam and never had an issue.
@@nikhayes3396 That is because the factory designed it that way. The calculate the airflow based on the airbox. Changing the air restriction has a big effect on mixture.
@@av8tor261 Assuming it's a K&N. There are so many knockoffs that perhaps that is the issue. Many chinese filters aren't the cotton fibers like K&N, they are cheaper fibers inside that may have a much more restrictive weave.
Needle goes UNDER the plastic cup under spring. Looks like you had it sitting on top. Check manual parts breakdown, but I believe that's your whole problem (I learned the hard way years ago :) . Don't run it too lean on that main Jet. Good luck
I updated the Navy's flight test manual for Pitot statics in 2019. Be careful assuming that static pressure is fine inside the open cockpit. Even an open cabin will likely not be totally at ambient conditions, because of airflow around the various openings causing suction or pressure. The difference may be small, but it's likely non-zero. For example, opening a side window of a car at highway speeds will often cause your ears to pop, as the Bernoulli effect causes suction out the open window. Opening different windows causes different pressures, depending on the flow over/around those windows. In this case, the pressure behind the windscreen is likely lower than ambient, as the air flows all around the windscreen and causes a low-pressure zone inside. Being directly behind the prop will also cause trouble, because that's a HIGH pressure zone. Finally, also remember that static pressure also affects airspeed accuracy, not just altitude accuracy. All in all, you're safer going with a static port that's in free-stream flow.
You two talented people work so well together. You make a very entertaining and informative video. (The wine advertisement was amazing!) I loved it. Thanks for bringing it to us.
Go to 10:08 in the video. The jet needle is improperly installed! It must be below the white plastic part...not above as you have it. The engine will not run correctly as shown and will be too rich for sure. This is probably your main problem.
I have a 447 on a quicksilver style ultralight , per rotax manual online it mentions jet sizing relative to elevation where you fly . I have stock jets slightly larger air filter runs good with no issues .
Always a learning adventure with you two…:) Fun video. Sure are ample comments with amazing depth of knowledge regarding the carbs. You have a ton of support!
Had a problem on two stroke bike where the RPM ran off. Cause was that too much air leaked in and we had to seal of and get a better filter. Maybe try to see if your air filter is not restricting air flow, especially with high air flow speeds caused by the props. (Low pressure) - Get some more air in there!
Hi Jonas, Looks like you got to much prop for the 447! Put in stock jetting and adjust pitch to get at least 6000 static rpm. I´m flying a Hi-max with a 447 and a Power Fin prop, had to cut diameter from 62´´ down to 60´´ to get rpm and temps ok! Love your videos! They are the best!! /Mike
The tiny air filter is highly restrictive. I’ve been involved with dozens of dyno tests of engines experimenting with air filter size and it’s common that people grossly undersize aftermarket air filters. My asthmatic grandmother who smoked for 60 years could breath better than that tiny, pointless air filter. Increase its size by a factor of 4, maybe even 6.
Hahaha I thought same thing he took it to go test fly then said it wasn’t running right I was like man throw that Chinese pocket bike air filter off of it and let the engine breath for god sakes
Hey Jonas, be careful dropping that needle. That’ll lean it in the midrange where you’ll be cruising mostly. Not sure if you’ve read the plugs while at cruise power setting , but I would be doing that if you are gonna play at the lean end of the needle settings
Jason , the problem you are having with the bogging is caused by needle and clip not being assembled correctly, use the recommended jetting , when installing the needle and clip ‘it should be needle and clip in the slide first then the white hold down spacer then the spring on top of that , when assembled you should not be able to push the needle up in the slide, it should be held firm by the spring on the white spacer . Your bogging is the needle floating up at higher rpm’s and causing a rich situation . Hope this helps !
Congratulations! And mouse nest free! I think you should go back to what you had for main jet. And adjust your needle in the slide back to where you had it. When tuning only change one thing at a time.
I had discounted the air cleaner as being the problem but I guess that was it. Looked good in the air. Looking forward the that full video. Loved the wine commercial. Well done, very creative. Now, pass me a glass from the the box please.
Hi Jonas, I noticed that your seatbelt is placed quite high across your waist. Without a 5th attach point,coming up from between your legs, it is possible to slide under the belt during a forward impact. This is called submarine under the belt. If you are not going to get a fifth point attachment try to wear the lap belt as low as possible.
Start with factory settings and work from that. Small steps at a time! You can not just change jets and fiddle with needle-height randomly without also ajusting air / fuel - screw (and idle).
Tons of good advise in the comments here to check out! I would say air filter isn’t helping anything but it sounds like it goes lean before dying to me so I would check fuel pump output and make sure the gas tank is vented properly.
Love you guys first of all!! Next I was thinking maybe there’s some crud in the fuel filter? I mean it was running fine the other day, so did you change anything before this run? Or maybe the fuel is boiling on the way to the carb with the fuel pump being mounted on the block? Take your time and get it really right before you get too far off the ground brother. We want to keep getting vids from ya! 🤠👍
Check your float height, seemed like fuel starvation rather than a lean condition. I would get the fuel issue figured out and go back to stock jetting. Maybe try it without that air filter on (cuz that's easy) but it seems like that bowl is running dry. Good luck!
Cool project. I fly the very similar Legal Eagle XL with a 1/2 VW. It's very squirrelly on the ground in any kind of gusty wind. The only other plane I've flown as PIC is a J-3, which is an absolute tank by comparison. Good luck! (PS: I found the prop blast around the fuselage to create significant vacuum at the instrument panel so I needed a static tube for my ASI.)
Jonas, a common problem is with the jet needle clip being above the white cup. It needs to be below the cup in the slide. Go back to the stock settings with the main jet of 165 and the clip in the second notch down from the top of the jet needle. I watched your video again and you do have it wrong. The jet needle in the clip needs to be BELOW the cup next to the bottom of the slide. This is your whole problem.
Nothing wrong with box wine 🍷, you guys are funny, corny but funny. Glad you found the problem with air filter can't wait to see next flight video, be careful.
It looks like your jet needle clip is located on the wrong side of the plastic retainer. The clip must be located under the plastic retainer and not above.
Hey Jonas, the cheap paint, on the wings did you brush or spray? I am going to be faced with something similar this year. I am definitely doing the latex process too
Jonas...I've been watching you for years and have the highest respect for your multiple skills. Your flying and engineering abilities are amazing. Silvia and Ava (I like the aviation reference!) are both gorgeous and I can tell you are wonderful loving family. That's why I'm commenting. I have well over 20,000 flight hours, a long career with the airlines and also an extensive background doing aviation safety work for my union, particularly with regard to fires. I'm now retired. I also survived general aviation inflight fire, but in the process was severely burned and came extremely close to dying. I carry the scars, which will be with me until I die. To the point of this comment: If not for yourself, for the sake of your beautiful wife and daughter, please consider the risk your are taking with this aircraft. Behind the hot engine and exhaust, you have what appears to be a plastic fuel tank. The fire I experienced got by the firewall. I did not see anything resembling a firewall on your machine. This causes me to ask what you think might happen if you happened to nose over even at the low speeds at which you fly? As I imagine that scenario, it creates a nightmare so graphic, I will not put it in this response. As I said, you have my deepest respect and admiration. I could never forgive myself if I do not at least give you a reason to think careful and consideration for the risks you are taking, particularly with this machine. To be honest, it looks like great fun. But please consider the possible price. I am an old pilot, so you know I am not bold. yumiandbob@gmail.com
I had same problem with a plane with a 582 blue top . What we found was that there was to much pitch on the prop .reduced by 2 deg and it was then perfect
Rotax 2-strokes seizing up are are very common thing, and it usually happens *when you fiddle with the jets in the carburetor or change the air filter to a non factory spec unit* You need to go by the book. If you don't get the RPMs change the propeller pitch. Never try to lean a 2-stroke, it will definitely die. Your prop looks like a Warp Drive, it is adjustable pitch. Use that.
It seems like your prop is over-pitched, Rotax two strokes will stall out in the middle of the rpm band if they have too much load. Get the jetting chart for the 447 on line (Aircraft Spruce) and make sure the engine is jetted to those specs. -tie the aircraft down, do a good warm up, then make sure the engine will pull 6200 rpm static at full power - if not, repitch the prop till it does. I use a gravity style protractor with the weighted dial indicator, blade set level length wise, and each one adjusted to the same pitch angle in turn. Once you have the rpm set to 6200 static. You can adjust the main jet to bring the exhaust temps to 1100-1150 degrees. I never tune them highervthan that to give margine for colder days or lower elevation flights.
Same crap happened at Kitty Hawk.Best thing is you retire for the evening and share a bottle of wine and your disappointment with Silvia. Wilbur got Orville. Cheers!
The stock jetting for a single carb 447, no intake silencer is as follows. Main jet=165. Idler jet= 45. Needle jet= 2.70. Jet needle= 15k2. Clip position= 2. Air screw turns out= .5. Check and make sure there is not a sliver of rubber stuck in the passage just above the float needle. I have found this problem many times. It comes from cutting new hoses, and not blowing them out afterward.
Block the carb/exhaust/fuel pump impulse line then pump it to 5 psi and it should hold for 3 minutes if it doesn’t use soapy water to find the air leak if they leak air they will never run right .good luck
Check the pitch of the prop, I bet it is over pitched for the engine, I ran into the same issue years ago, went through everything on the engine, turned out to be the prop wasn't flat enough
The wine commercial.....reminds me of the time I took a Italian girlfriend, who was a visiting professor in microbiology (and para glider pilot) and super smart, to the El Rancho for a drink. She asked what types of wine they had, and the local Inkom girl bartender said "red and white, and it comes in a box, what do you want?" Horrified her, cracked me up!
The carb looks like an Amal motorcycle carb, they were prone to fuel frothing in the float chamber from a high speed vibrating motor resulting in incorrect mixture strength. The fix was to remote mount the float chamber or remote mount the entire carb by using a rubber hose or rubber block to isolate the carb from the engine. It's important to have an air cleaner on at all times incase the motor blows back through the carb with flames, another point, air filters keep dust out that may clog the carb body causing the barrel slide to bind and not able to return to idle RPM. Cheers 👍
Great to see you in the air again, well almost, but really miss your adventures in the KitFox. Messing with the mixture jets can hole a piston....ask me how I know🤣 Peace from Rome👍🇬🇧
Jonas, u need ditch that air cleaner for one without a solid end cap you will never jet it right otherwise, pulse rebounds off and picks up a bit gas each time.. swap for a foam one..
I have the same engine on my ultralight. DO NOT use avgas and make sure you're 50 to 1 gas mixture. And have you made sure the choke is off completely? And I know from experience that if your float let's the bowl get too full it will all seem fine till you get about wide open and a combination of more fuel pump pressure and vibrations and all that makes it overflow spitting extra fuel into the intake causing it to suddenly bog down and fall on its face. When you let off throttle it will seem normal again but it will repeat soon as you go for it again. Had a snowmobile do this with a pretty similar engine and a Bing carburetor. Was a bitch to figure out but once I did it ran like a champ. Oh and make darn sure you dont use gas with any alcohol content! 100% gas, 87 octane is what they run best on. 👌
Yeah non oxygenated premium is what we use and recommend for all small engines, but a little 100 LL shouldn't hurt, we have used it in small engines no prob. it won't detonate easily anyway! Ha!
Did you checked the fuel filter? It may be a dirty and that's why the engine does not give al the rpm. Also, you can try cleaning up the carburator enterely and reduce the light of the spark plugs. That's all my experience with the damn R447 jajaja. Regards from Argentina.
I had trouble like that in a Van I had. I stopped at a full-service gas station and told the mechanic what it was doing and he looked at it then changed all the rubber hoses on the engine and the van ran great after that. That's the same engine we worked on that were in Snow-Mobil Engines. They were always trouble.
I have about a 1000 hours of Rotax experience and I think you're chasing your tail with all the jet changing. Put in the jets that the manual calls for based on your MSL altitude. Nothing wrong with the air filter...it's the one recommended for a single Bing carb Rotax. Make sure you're getting good fuel flow to the carb (put in a new fuel filter). Fuel pump could be a problem but probably not. Tied down on the ground the engine should reach a max static RPM of about 6200. Much more or less means you have the wrong prop pitch setting. All this assumes that the engine is in good condition. Since it set unused for so long the seals may be bad which will totally screw up the engine performance. BTW, the Rotax break-in procedure is a good way to abuse an engine. It puts too much stress on the engine and overheats the engine. Do you have good instrumentation...rpm, CHT, EGT. CHT under 400, EGT under 1100 is safe...the book redline numbers are sketchy. Good luck and when the engine quits (when not if) just land it like a glider.
I just re-watched and Jonas you mentioned putting on a new air filter. Maybe their is a restriction in the new one or it just isn’t allowing the engine to get enough air in general.
That’s interesting about breaking in the Rotax 447 that is what I have on my quicksilver. I redid the pistons and rings and board out the cylinders I never did a break in maybe I didn’t have too.Not sure 🤔
Rotax has two sized float needles, small for use with pump and large for overhead fuel tanks (without pump). A large needle with fuel pump Will over power the float and flood the carb when the rpm is increased. Gravity carbs need large needles to flow enough fuel without a pump (very low pressure) Have seen this a few times. I can’t tell from videos but worth checking
Cool little puddle jumper the Airbike is! And yay it flew, a little bit anyway. It's been bucking ya Jonas but hang in there you'll get it. I been eyeing the Badlands, used to be the kitfox lite. Wider cockpit n your feet are inside. It's flippin cool to cold up here for way to much of the year!
I see someone suggested the stock carb settings... next you need a bigger air filter. What you have is restricting the airflow into the carb at higher RPMs so you are running rich at high RPM. That's why it was running great when you didn't have the air cleaner on it. What you are using looks like it's got about a third the filter area you need.
My knee jerk reaction after working on a number of 2-cycles (Snowmobiles) when I was younger when you installed that air filter was, "That's gonna starve it of air." (Especially when you foreshadowed that there was power problems) Temporarily try it without the air filter? Like has been suggested, use a larger air filter? Mike Patey it and make a carbon fiber air intake that forces air into the filter and actually flies the airplane while you have a rum and coke...
@@jamesgrossmann866 ???
I’m not much for watching commercials I usually skip past them, well done you two I watched the whole thing.
Anytime you're dealing with a carb, first step is to verify the float (fuel) level is at the specified point. That affects the jetting and you'll be chasing your tail till it's right. You can put a clear fuel tube on the bowl drain, run it up above the carb and see where the fuel level is sitting inside. It sounds to me like it's not getting enough fuel. I wonder if that fuel pump is keeping up at full power? Watching the fuel level in the bowl while it's running will tell you for sure.
You’re referring to pop-off pressure of the float bowl needle valve. This can be checked with a pressure gauge and set with the appropriate spring tension. No need to see the level in the float bowl, just verify it opens and closes at the correct pressure and the fuel will be where it should.
With Rotax 2-strokes you should always use the stock jets, needles, and carb. You adjust prop pitch and Length to achieve Rotax’s rpm, egt, and cht parameters. If too much prop it will running rich, Cht will be high, EGT will be low, and it will not reach max rpm. If so you take out pitch or shorten blades. If too little prop you’ll see low CHT, high EGT, and too high of rpm. Then you should add more pitch or length. also run the proper air filter. Also found too soft of a fuel line from tank to pump can cause the fuel pump to lose suction.
Totally correct. A friend runs these engines in racing hovercraft. Start at factory settings & fine tune with an EGT. An EGT gauge is worth having in the cabin - you can see potential seizures before they happen.
This is the only channel that I actually enjoy watching the “ads”. Great job Jonas keeping your fans interested!
You guys are pretty creative with those “sponsored ads”. Funny stuff.
Totally agree, they do it better than anyone else, a great sense of humor.
Yeah we're gonna need to hear more from Big J and Marge!
Used to tune, ride and race a 350cc 2 stroke motorcycle. You have a 447 twin and that air filter looks waaay too small, especially for feeding 2 cylinders. The consequence would be restricting airflow more and more as rpms increase, leading to increasingly rich mixture and bogging. My 350 twin had 2 filters on 2 carbs that each were at least 4 times the size of yours. Your original engine testing and break-in showed no air filter--a huge difference in the very sensitive 2 stroke engines. Love your bringing this air-bike back to life!!
Agreed! I took it off and it ran beautifully
Hey Jonas, try a larger air filter. You said you put a new one on? I had a Hirth engine and tried one of those filters and it didn't like it.
Yup! That’s what it was!
Try the factory Jets/ Settings.. 165 Main, 45 pilot, needle clip 2 down from top, air screw .5 turn out from closed. I have the same engine in my Firefly and it runs great with the factory settings. Plugs will tell you if it's rich or lean. Cool plane!
Can’t help to notice your last name? Do you have Lithuanian roots?
@@siiilvija1 were all glad you do ; ) Spices things up a bit.
@@siiilvija1 Yes! My father was Lithuanian and Mother was Finnish. Of course I'm a Jurgis Kairys fan :)
@@bkairys how wonderful! Do you speak Lithuanian? Are you related to Jurgis Kairys?😀
@@siiilvija1 I wish! Born and raised here in Michigan. I enjoyed your Lithuania videos. Cool to see my homeland for first time! You guys make great videos! Jonas is one of my favs to watch! Keep up the good work.
Jonas: "It's always good fun being a test pilot." Silvija: "No it's not, it's not fun at all!" ; )
Exactly!!!
Lol
The way you look and talk for a moment I thought you were Trent Palmer! Great video guys!
I gotta say I’ve never seen an air filter that small on a twin cylinder engine…factory jetting and larger air filter is the place to start…
After watching your video I then read all the comments. Jonas, you have some great fans who really seem to know their stuff. Watching you and Silvija is an adventure unto itself.
Cool video. If you haven't figured it out yet, here's the fix: Drain the fuel and put it in your pickup. Get fresh fuel and 50:1 synthetic 2-stroke. Return all carb settings to factory setting. Anchor rear of plane using rope, start engine and do warm-up/run-up. Untie rope and fly away.
Two strokes, man, always a pain. Motocrossed two strokes for years, constant upkeep and re-jetting. Occasionally a seize up and rebuild! Fun stuff! Also, love the ads! You guys are great.
Love seeing you get that bird up (even for just a second). I will commend you on your in video sponsorship ads. They are one of the only ones that I actually enjoy watching. Keep it up.
Hi Jonas ans Silvia, as far as I can see your carburator has bien wrongly reassembled. The clip maintaining the needle must be placed underneath the white plastic part and not over. Don't forget to get back to the good settings of jets and needle then before next run up.
Good Luck
Jean-Luc from France
Looks like you are the first one to catch that. It was so obvious.
Sounds to me like it's running the bowl dry. You'll need to raise the fuel level in the bowls by bending the tab on the floats so that they're higher in the bowl. That's if the pump is working correctly, and any fuel filters and lines are free flowing and unobstructed. Sounded like it was running rough on the runway, but after hearing it from Silvija's video, it sounded fine - the wind noise was distorting the sound.
Made some great progress on that, Jonas! Great to see that thing flying at the end there! Looks like so much fun! I can't seem to get a day with light winds out here in the Northeast for the paramotor - every day is either freezing cold, howling winds, or raining. I can't wait for summer! I want to move to FL, but I can't convince my wife of that idea, sadly. Some day! Tired of this cold crap! Maybe I'll burn some tires to speed up this global warming thing. 😂
The EGT is your tuning tool but that reading will be inaccurate if the fuel supply isn't keeping up but the color on the plugs tells the ultimate story. For the thing to actually die under power, that indicates it has a fuel supply issue.
A restricted airflow (air filter) would cause it to go rich at higher power settings; acting like a choke plate. I'd try it with no air filter.
Not true. Rotax has designed the jetting for a filter. No filter is asking for trouble so keep you self proclaimed expert advice to yourself.
BTW. K&N air filters are the least restrictive on the market (if properly maintained). EGT tells all.
@@av8tor261 relax, you crazy person.
I put one of those “high performance” filters on a little dirt bike and couldn’t ever get it to run right consistently. went back to the stock foam and never had an issue.
@@nikhayes3396 That is because the factory designed it that way. The calculate the airflow based on the airbox. Changing the air restriction has a big effect on mixture.
@@av8tor261 Assuming it's a K&N. There are so many knockoffs that perhaps that is the issue. Many chinese filters aren't the cotton fibers like K&N, they are cheaper fibers inside that may have a much more restrictive weave.
Needle goes UNDER the plastic cup under spring. Looks like you had it sitting on top. Check manual parts breakdown, but I believe that's your whole problem (I learned the hard way years ago :) . Don't run it too lean on that main Jet. Good luck
I updated the Navy's flight test manual for Pitot statics in 2019. Be careful assuming that static pressure is fine inside the open cockpit. Even an open cabin will likely not be totally at ambient conditions, because of airflow around the various openings causing suction or pressure. The difference may be small, but it's likely non-zero. For example, opening a side window of a car at highway speeds will often cause your ears to pop, as the Bernoulli effect causes suction out the open window. Opening different windows causes different pressures, depending on the flow over/around those windows. In this case, the pressure behind the windscreen is likely lower than ambient, as the air flows all around the windscreen and causes a low-pressure zone inside. Being directly behind the prop will also cause trouble, because that's a HIGH pressure zone. Finally, also remember that static pressure also affects airspeed accuracy, not just altitude accuracy. All in all, you're safer going with a static port that's in free-stream flow.
Thanks for the information! I didn’t realize this.
You two talented people work so well together. You make a very entertaining and informative video. (The wine advertisement was amazing!) I loved it. Thanks for bringing it to us.
Go to 10:08 in the video. The jet needle is improperly installed! It must be below the white plastic part...not above as you have it. The engine will not run correctly as shown and will be too rich for sure. This is probably your main problem.
I have a 447 on a quicksilver style ultralight , per rotax manual online it mentions jet sizing relative to elevation where you fly . I have stock jets slightly larger air filter runs good with no issues .
You guys make the cutest commercials
Hello from Minnesota!! Lots of good advice in the comments! Can't wait to see you fly it.
Always a learning adventure with you two…:) Fun video. Sure are ample comments with amazing depth of knowledge regarding the carbs. You have a ton of support!
Had a problem on two stroke bike where the RPM ran off. Cause was that too much air leaked in and we had to seal of and get a better filter. Maybe try to see if your air filter is not restricting air flow, especially with high air flow speeds caused by the props. (Low pressure) - Get some more air in there!
Hi Jonas, Looks like you got to much prop for the 447! Put in stock jetting and adjust pitch to get at least 6000 static rpm.
I´m flying a Hi-max with a 447 and a Power Fin prop, had to cut diameter from 62´´ down to 60´´ to get rpm and temps ok!
Love your videos! They are the best!!
/Mike
The tiny air filter is highly restrictive. I’ve been involved with dozens of dyno tests of engines experimenting with air filter size and it’s common that people grossly undersize aftermarket air filters. My asthmatic grandmother who smoked for 60 years could breath better than that tiny, pointless air filter. Increase its size by a factor of 4, maybe even 6.
Hahaha I thought same thing he took it to go test fly then said it wasn’t running right I was like man throw that Chinese pocket bike air filter off of it and let the engine breath for god sakes
Hey Jonas, be careful dropping that needle. That’ll lean it in the midrange where you’ll be cruising mostly. Not sure if you’ve read the plugs while at cruise power setting , but I would be doing that if you are gonna play at the lean end of the needle settings
I hope one day they'd create Oscars for UA-cam ads. You won it already! Alos, the plane is really cool!
Ha thanks! 🙏
And the adventure continues. Way to go Jonas! Nice to meet you at Ty's wedding. Roland
It was nice meeting you also!
Thought it was so cute when you said sauvignon blanc because you unexpectedly nailed it.
Check the reed valves for adjustment / wear. Worst comes to worse you can pressurize the crank case to check the seals for leakage.
Rotax doesn't use reed valves
I was juuuust about to go to bed and you uploaded, had to watch, congrats on first air! You'll get there!
Jonas, I figured it out! Have you checked the tire pressure?….. love you guys.
Jason , the problem you are having with the bogging is caused by needle and clip not being assembled correctly, use the recommended jetting , when installing the needle and clip ‘it should be needle and clip in the slide first then the white hold down spacer then the spring on top of that , when assembled you should not be able to push the needle up in the slide, it should be held firm by the spring on the white spacer . Your bogging is the needle floating up at higher rpm’s and causing a rich situation .
Hope this helps !
Congratulations! And mouse nest free! I think you should go back to what you had for main jet. And adjust your needle in the slide back to where you had it. When tuning only change one thing at a time.
I had discounted the air cleaner as being the problem but I guess that was it. Looked good in the air. Looking forward the that full video. Loved the wine commercial. Well done, very creative. Now, pass me a glass from the the box please.
Love the video…you two have the best ads ever!
Hi Jonas,
I noticed that your seatbelt is placed quite high across your waist. Without a 5th attach point,coming up from between your legs, it is possible to slide under the belt during a forward impact. This is called submarine under the belt. If you are not going to get a fifth point attachment try to wear the lap belt as low as possible.
Good to know! Thanks
You REALLY do the BEST adds!!! haha I actually watch yours!
Check your fuel line connections. If any air gets in with the fuel it will bog.
Start with factory settings and work from that. Small steps at a time!
You can not just change jets and fiddle with needle-height randomly without also ajusting air / fuel - screw (and idle).
Love those 6-way screwdrivers, too.
Tons of good advise in the comments here to check out! I would say air filter isn’t helping anything but it sounds like it goes lean before dying to me so I would check fuel pump output and make sure the gas tank is vented properly.
OK.. Super. The Wright brothers would have been proud of you Jonas. Looks like a fun A/C to fly.
I enjoyed that bright cellars ad! 😂
Just curious if you might be to rich on your pre-mix. The oil can settle in your fuel after sitting
Love you guys first of all!! Next I was thinking maybe there’s some crud in the fuel filter? I mean it was running fine the other day, so did you change anything before this run? Or maybe the fuel is boiling on the way to the carb with the fuel pump being mounted on the block? Take your time and get it really right before you get too far off the ground brother. We want to keep getting vids from ya! 🤠👍
Check your float height, seemed like fuel starvation rather than a lean condition. I would get the fuel issue figured out and go back to stock jetting. Maybe try it without that air filter on (cuz that's easy) but it seems like that bowl is running dry. Good luck!
Paragliders don't need propellers, paramotors do though..lol
Cool project. I fly the very similar Legal Eagle XL with a 1/2 VW. It's very squirrelly on the ground in any kind of gusty wind. The only other plane I've flown as PIC is a J-3, which is an absolute tank by comparison. Good luck!
(PS: I found the prop blast around the fuselage to create significant vacuum at the instrument panel so I needed a static tube for my ASI.)
Interesting! I wouldn’t think that. Thanks for the info!
The Legal Eagle is a cool airplane 😎
Jonas it was nice see its come off then ground you will get it tuned in nice to see you two again, God bless you.
Jonas, a common problem is with the jet needle clip being above the white cup. It needs to be below the cup in the slide. Go back to the stock settings with the main jet of 165 and the clip in the second notch down from the top of the jet needle. I watched your video again and you do have it wrong. The jet needle in the clip needs to be BELOW the cup next to the bottom of the slide. This is your whole problem.
Nothing wrong with box wine 🍷, you guys are funny, corny but funny. Glad you found the problem with air filter can't wait to see next flight video, be careful.
It looks like your jet needle clip is located on the wrong side of the plastic retainer. The clip must be located under the plastic retainer and not above.
Hey Jonas, the cheap paint, on the wings did you brush or spray? I am going to be faced with something similar this year. I am definitely doing the latex process too
I just brushed on for the repair. Spray would be ideal though.
Jonas...I've been watching you for years and have the highest respect for your multiple skills. Your flying and engineering abilities are amazing. Silvia and Ava (I like the aviation reference!) are both gorgeous and I can tell you are wonderful loving family. That's why I'm commenting. I have well over 20,000 flight hours, a long career with the airlines and also an extensive background doing aviation safety work for my union, particularly with regard to fires. I'm now retired. I also survived general aviation inflight fire, but in the process was severely burned and came extremely close to dying. I carry the scars, which will be with me until I die. To the point of this comment: If not for yourself, for the sake of your beautiful wife and daughter, please consider the risk your are taking with this aircraft. Behind the hot engine and exhaust, you have what appears to be a plastic fuel tank. The fire I experienced got by the firewall. I did not see anything resembling a firewall on your machine. This causes me to ask what you think might happen if you happened to nose over even at the low speeds at which you fly? As I imagine that scenario, it creates a nightmare so graphic, I will not put it in this response. As I said, you have my deepest respect and admiration. I could never forgive myself if I do not at least give you a reason to think careful and consideration for the risks you are taking, particularly with this machine. To be honest, it looks like great fun. But please consider the possible price. I am an old pilot, so you know I am not bold. yumiandbob@gmail.com
Weather’s been the same here in Minnesota this spring too! 😖 😝
I had same problem with a plane with a 582 blue top . What we found was that there was to much pitch on the prop .reduced by 2 deg and it was then perfect
Rotax 2-strokes seizing up are are very common thing, and it usually happens *when you fiddle with the jets in the carburetor or change the air filter to a non factory spec unit*
You need to go by the book. If you don't get the RPMs change the propeller pitch. Never try to lean a 2-stroke, it will definitely die.
Your prop looks like a Warp Drive, it is adjustable pitch. Use that.
It seems like your prop is over-pitched, Rotax two strokes will stall out in the middle of the rpm band if they have too much load. Get the jetting chart for the 447 on line (Aircraft Spruce) and make sure the engine is jetted to those specs.
-tie the aircraft down, do a good warm up, then make sure the engine will pull 6200 rpm static at full power
- if not, repitch the prop till it does.
I use a gravity style protractor with the weighted dial indicator, blade set level length wise, and each one adjusted to the same pitch angle in turn.
Once you have the rpm set to 6200 static. You can adjust the main jet to bring the exhaust temps to 1100-1150 degrees. I never tune them highervthan that to give margine for colder days or lower elevation flights.
Please don't stop the commercials.
Too funny!!!
Wow ! You made it. It flew for real ! Bravo !!! 🤠👍👍
Same crap happened at Kitty Hawk.Best thing is you retire for the evening and share a bottle of wine and your disappointment with Silvia. Wilbur got Orville. Cheers!
The stock jetting for a single carb 447, no intake silencer is as follows. Main jet=165. Idler jet= 45. Needle jet= 2.70. Jet needle= 15k2. Clip position= 2. Air screw turns out= .5. Check and make sure there is not a sliver of rubber stuck in the passage just above the float needle. I have found this problem many times. It comes from cutting new hoses, and not blowing them out afterward.
Good to know! Thanks
Liked your Bright Cellars commercial. Nice looking couple...and purdy lookin' couple.
You actually got me to watch a wine ad...
And I don't drink. 😊
To bad UA-cam didn't pay you for it.
Check out lectron carb. The best setup for 2 strokes no jets at all automatic altitude compensation. 10 minutes you are done
I need one!
I think I would use a lot less fuel for testing like this!
Good catch!
I was thinking the same thing when I saw all that fuel in the tank
The wine commercial was GREAT. Had me LOL. At the other end of the scale are those dumb Kayak commercials.
Is it stumbling or just short of RPM? If the latter, check your prop pitch (is too agressive/coarse)
It was the air filter! I took it off and reached full RPM.
Block the carb/exhaust/fuel pump impulse line then pump it to 5 psi and it should hold for 3 minutes if it doesn’t use soapy water to find the air leak if they leak air they will never run right .good luck
For audio in flight, Tucker Gott has some sort of setup that seems to work well.
I don't drink wine but watched the whole wine spill it was a hoot🤣
Check the pitch of the prop, I bet it is over pitched for the engine, I ran into the same issue years ago, went through everything on the engine, turned out to be the prop wasn't flat enough
The wine commercial.....reminds me of the time I took a Italian girlfriend, who was a visiting professor in microbiology (and para glider pilot) and super smart, to the El Rancho for a drink. She asked what types of wine they had, and the local Inkom girl bartender said "red and white, and it comes in a box, what do you want?" Horrified her, cracked me up!
😂 love it
The carb looks like an Amal motorcycle carb, they were prone to fuel frothing in the float chamber from a high speed vibrating motor resulting in incorrect mixture strength. The fix was to remote mount the float chamber or remote mount the entire carb by using a rubber hose or rubber block to isolate the carb from the engine. It's important to have an air cleaner on at all times incase the motor blows back through the carb with flames, another point, air filters keep dust out that may clog the carb body causing the barrel slide to bind and not able to return to idle RPM. Cheers 👍
Great to see you in the air again, well almost, but really miss your adventures in the KitFox. Messing with the mixture jets can hole a piston....ask me how I know🤣
Peace from Rome👍🇬🇧
I love Sylvia's fancy wine accent😅
Haha thanks😂
Do I see at 12:45 the fuselage tubes flexing? (from the engine to the wing)
Jonas, u need ditch that air cleaner for one without a solid end cap you will never jet it right otherwise, pulse rebounds off and picks up a bit gas each time.. swap for a foam one..
Also some fuel/oil separation if its sat a long time. Reminds me of my fussy old purchased in '78 Skil chainsaw. Yes gum forms if it sits all winter.
I've heard from other 2 stroke flyers the fuel pump is better mounted flat rather than vertical. I don't know why but they all seem to mention it.
I have the same engine on my ultralight. DO NOT use avgas and make sure you're 50 to 1 gas mixture. And have you made sure the choke is off completely? And I know from experience that if your float let's the bowl get too full it will all seem fine till you get about wide open and a combination of more fuel pump pressure and vibrations and all that makes it overflow spitting extra fuel into the intake causing it to suddenly bog down and fall on its face. When you let off throttle it will seem normal again but it will repeat soon as you go for it again. Had a snowmobile do this with a pretty similar engine and a Bing carburetor. Was a bitch to figure out but once I did it ran like a champ.
Oh and make darn sure you dont use gas with any alcohol content! 100% gas, 87 octane is what they run best on. 👌
Yeah non oxygenated premium is what we use and recommend for all small engines, but a little 100 LL shouldn't hurt, we have used it in small engines no prob. it won't detonate easily anyway! Ha!
Did you checked the fuel filter? It may be a dirty and that's why the engine does not give al the rpm. Also, you can try cleaning up the carburator enterely and reduce the light of the spark plugs. That's all my experience with the damn R447 jajaja. Regards from Argentina.
watch where your float bowl vent is as well, seems more trouble on the roll
I had trouble like that in a Van I had. I stopped at a full-service gas station and told the mechanic what it was doing and he looked at it then changed all the rubber hoses on the engine and the van ran great after that. That's the same engine we worked on that were in Snow-Mobil Engines. They were always trouble.
You got to love the bing carburetors 🤔
Finally! Some flying content 👍🔥🔥🔥👍
I have about a 1000 hours of Rotax experience and I think you're chasing your tail with all the jet changing. Put in the jets that the manual calls for based on your MSL altitude. Nothing wrong with the air filter...it's the one recommended for a single Bing carb Rotax. Make sure you're getting good fuel flow to the carb (put in a new fuel filter). Fuel pump could be a problem but probably not. Tied down on the ground the engine should reach a max static RPM of about 6200. Much more or less means you have the wrong prop pitch setting. All this assumes that the engine is in good condition. Since it set unused for so long the seals may be bad which will totally screw up the engine performance. BTW, the Rotax break-in procedure is a good way to abuse an engine. It puts too much stress on the engine and overheats the engine. Do you have good instrumentation...rpm, CHT, EGT. CHT under 400, EGT under 1100 is safe...the book redline numbers are sketchy. Good luck and when the engine quits (when not if) just land it like a glider.
Good answer 👍☀️😎
I just re-watched and Jonas you mentioned putting on a new air filter. Maybe their is a restriction in the new one or it just isn’t allowing the engine to get enough air in general.
That was it! 😑 runs beautiful now.
@@JonasMarcinko AWESOME BROTHER!!!
Sounds like it's running out of fuel. Bad pump? Blocked line? Pulling a vacuum on the tank?
So happy to see people working on planes like they work on cars. Dangerous but thrilling!
That’s interesting about breaking in the Rotax 447 that is what I have on my quicksilver. I redid the pistons and rings and board out the cylinders I never did a break in maybe I didn’t have too.Not sure 🤔
Rotax has two sized float needles, small for use with pump and large for overhead fuel tanks (without pump).
A large needle with fuel pump Will over power the float and flood the carb when the rpm is increased.
Gravity carbs need large needles to flow enough fuel without a pump (very low pressure)
Have seen this a few times.
I can’t tell from videos but worth checking
Cool little puddle jumper the Airbike is! And yay it flew, a little bit anyway.
It's been bucking ya Jonas but hang in there you'll get it.
I been eyeing the Badlands, used to be the kitfox lite. Wider cockpit n your feet are inside. It's flippin cool to cold up here for way to much of the year!