How to tune a chainsaw carburetor
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- Опубліковано 9 лип 2024
- How to tune a chainsaw carburetor for the most power. Dyno testing tunes to see which performs the best. A rich tune vs lean, then a tune that is just right.
Talk about the different sounds and symptoms from the tunes. What to listen for to dial in the correct tune. From seasoned loggers, arborist, tree service professionals, to homeowners wanting a saw to keep the yard up.
2 strokes need to have a good tune to keep performance up.
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#echo#carburetor tuning#chainsaw #small engine#stihl#chain saw#husqvarna#two stroke#how to tune a chainsaw#carburetor adjustment#carb tuning#shindiawa
So many tuning videos start with "Here's how to tune a saw, but this one doesn't need it." This is not one of those videos. The dyno, real life exhaust sounds, and Joes' narration teach us what we actually need to know. Thanks!
Just awesome to see blank numbers instead of "feelings" Thank you for sharing this with us.
Cheers from Germany
Thank you for watching. Hope it is helpful information.
An absolute amazing video. Love the dyno demonstration with the graph. Really helps paint the picture for me
excellent job explaining tune. finally a video that explains high rpm doesn't give any more hp ; whats important is a proper tune.love the video
This is, by far, the best explanation and demonstration of tuning I've ever seen. Thank goodness! I'm echoing a number of the previous comments, but there seems to be a tremendous emphasis today on high RPMs as if people think that's going to lead to more production. I think this answers that argument! 👍💪
That's a great visual. Thanks Joe!
This helped a ton and I have watching vids for years and never quite got it. thanks
Very good job on the demonstration. One of the best youtube's I seen on tuning the carb of a chainsaw.
Thank you, I really appreciate it.
I hope this helps you out if you need to tune your saw.
Excellent description. Thanks, Joe.
Excellent job explaining everything as well as showing on a dump what is the best performing tune. Thanks for the vid
Thank you for watching.
Excellent demonstration. Thanks for explaining how the powerband and usable rpm range works. I've seen other saw "builders" testing wide open throttle rpm with a tachometer, as if maximum rpm means anything. Keep your eyes on Joe. He's going to teach us.
Max rpm can keep you in the safe max range without going into that danger zone.
There is a reason for the tachometer.
Awesome video. Very insightful and graphs to back it up.
Thank you
Keep up the content. Real data vs feelings. Great teaching tool!
Yes it is.
Although it can be a very upsetting tool when looking for gains.
Thank you for watching.
Very good analysis on carb t/s and tuning
Love my 590. Thanks for tips!
Excellent vid Joe.
It's cool seeing the results on the computer screen rather than just hearing it.
Thank you
Best explanation I've found!
Good demonstration👍 I like to set the low jet rich enough for good response and just lean enough to idle for as long as the saw sits. And high jet, I've always tuned in the wood. Slightly 4-stroking with just the weight of the saw, cleans up when you dog it in or push on it. So far so good! Haven't killed a saw yet!
Great stuff man👍🏻
I would like to echo- hehe -many of the comments. Chainsaw tuning videos without a dyno are way too abundant and are heresay at best. This is very useful.
Great info. Comparing the 4-stroke to the 2-stroke sound repeatedly was very useful.
Thank you.
Glad to hear it was helpful
You really do some informativd vids. Great content.
Bloody brilliant info right there!
Thanks mate 👊
Thank you for watching.
Great demonstration of 4 stroking.
Among other topics I had on my to do list I was going to do a video on the principles of why 2 strokes 4 stroke.
This provides a good demonstration of not just 4 stroking under rich conditions but also in respect of brake load on the engine.
I had planned to use a leaf blower for the exercise but instead I might point viewers to this video in future.
Thank you.
I would appreciate it.
Excellent presentation and explanation.
Thank you
Great video!
Awesome ! Thanks a lot!
Great video Joe!
Not just how to tune, but what those tunes actually yield as far as output of the engine!
Dyno: great video. Thanks for helping out hackers like me figure this out
thanks this is a excellent video
Very cool and informative. Subbed. 👍
Thank you Joe
Great video-Thanks!
Thank you
Very nice Joe.
Thank you
Nice job well done I have tried it with a tachometer but I always end up having to rich them up now I see why thanks
Thanks Joe
Good video
Great video! Would you mind making another that concentrates one the sounds the saw should and shouldn’t make? I think it would be very helpful especially in the field and would get a ton of likes!
Thanks again,
The problem I have tuning this saw, and other rev limited coil saws, is differentiating between hitting the rev limiter and four stroking with a rich tune. In this video, the rich tune sounds similar to my 590 rev limiter. I know the difference , but it took a while and a lot of tuning to learn the difference. PITA
Nice brother ❤️👍
Good info.
Thank you so much.
Thanks for this video Dyno Joe. Now I see why the limiters have to be removed sometimes.
Can't explain any clearer than this fine example of how a carburetor tune can make you or break you 😉
For 2-cycle motors, max out the high speed with highest rpm, then richen the fuel mixture to lower the rpm. Then set idle and go to work.
Aboo nice guy !
Got to have fuel to make power and keep her cool.👍 That dyno is a game changer.
Yessir fuel and air makes the crank go round
@@dynojoemods2764 An air pump they are.
Thank you. I’ve always wanted to know what was meant by the term ‘4-stroking’ and didn’t know what it sounded like.
Glad it helps clear that up.
Thank you for watching.
Nice video in general. One thing could be shown, is the picture/ video of adjusting the high and low screws and how to turn them clockwise or anti....
Here is the part number walbro 86-578-1 nozzle. I have this installed in a 620 carb mounted to the cs590. Now you need the 620 unlimited coil and re tune and re dyno. You should get another 1000rpm in the cut.
Yeh the porting/stock muffler didn't want much over 12k on this 590. The hotter 620 coil is more helpful after porting. Really wakes up throttle response
Comment from me today.
Why do my saws (all under about 60cc) seem to be very sensitive to weather, seems like I need to adjust when warmer or colder weather. I did open up exhaust, simple mod. Removed guts ,no pipe. . Did I make to much flow ?
Very good, liked hearing the sound verses tuning. Couldn't help but notice the chains was very loose after the dyno load test. Soft chain?
Left it a bit loose since I was doing much longer runs. Keep rhe hear down. As I dont use a ton of oil.
This is great info. I want to send you my 590 and 4910 for porting package. I need more wood cutting power!
Thank you, just let me know when.
@@dynojoemods2764 thanks 🙏🏼 hopefully soon! The 590 is now outta warranty. The 4910 is only a year old but my go to saw since it sits in my saw haul on the tractor when I'm out getting firewood. I just took out the restricter tube and bent the tabs open. It helped a lot, but still need more power!
Great video! I’d be interested to see the power difference with a lean or rich tune on the L jet. I feel like in some saws I have noticed a power difference in the cut after adjusting the low. Can this be?
Yes, if the L is out of tune it can effect power some. Especially in the transition area from H to L side of the carb.
Man I love this! I port my own work saws. I’m wondering if you would be interested putting one of my ported 372xt husky’s on your dyno? I also have a stock 372xt. I have always wondered what the actual power gain is with what I do porting wise. There is definitely a increase in power. I gain about 3 seconds over a stock saw in a 23” log running same bar and chain. Anyway if you are interested I would pay for the shipping. And you for your time! Thanks new subscriber here!
Thank you!
Visit my website www.worksaws.com
I have all my services and prices listed.
Hello jake mesa nice to see u here sir
@@dynojoemods2764 372 xp oe 13200 rpm max ok?
what does HMWF LLC stand for?
👍👍👍
I would like a more in depth explanation of low vs high jet. Where is the changeover? I can adjust my low jet for max rpm then turn my idle screw down. I can also lower rpm by turning my low jet out. From what I have watched the consensus seems to be tune the low for max rpm then turn to rich until rpm just starts to drop. Then adjust idle to correct rpm. Do you agree?
Have you ran the numbers for that saw with a 590 carb ? Would be interesting to see the difference with just the carb change. Good video.
Without a muffler mod or cylinder porting. The larger carb by itself won't gain much power at all. Now if you modify, then the large carb really starts to shine.
Very interesting. Thanx for sharing. One of my smaller husky saws kind of bogs and don't run well when it is cold and dies if not held running. Once it has working temp it is runs ok . Any idea why?
It is very hard to tell without hearing it.
Try turning the L screw Counter clock wise. 1/8 of a turn and see if it helps anything. Depending on the age of the saw it may be due for a carb kit and fuel lines.
@@dynojoemods2764 It is a relative new secondhand 440 II e, that cut down only two logs before i got it.. Cylinder and piston is fine. Only premixed fuel here so i guess carbkit probably is not necessary. My guess s about 5 liters of fuel in total. I will try out what you suggest. Thanx!
@@skrompf
Try counter clockwise first, if no better try the other direction. But it sounds like a L side adjustment issue
Joe Harkness is that Er70s2 as a pointer? Love it bud!
Yep, filler rod, pointer, back scratcher... many uses.
When you are biulding saw for most hp. Have short blow down like 18 deg. Or would you have long blow down Like 22 to 25 deg. This would on 66 cc saw
From base start at 1 turn out each starting w choke then off
Start it’ll run but stahl out
Which do I start with low or high
It’s difficult to start with the law when it stalls right out I believe easier to start with the high well you’ve got it hammered down and get it to peek out and then start settling in the bottom end I understand that if you have a good throttle response the low is close but I have a difficult time finding correct idle with the idle screw and the low tune screw please advise
This is a Poulan 42 cc not my choice of saw working on it for a friend plus I have another craftsman/ Poulan ( old cast case)that gave me the same issue
Carburetor has been taken apart ports cleaned etc. everything looks good, clean gas, air, good spark plug
Sounds like it might like a little more open both H and L but it is super difficult to tell without being able to hear the saw.
I understand that ☺️
That’s how it got on my bench in the first place-lol. I let it sit overnight with some sea foam
And will try again tomorrow
Ty for your time-👍🏼
Joe, do you need a handle for that?
I think I have one around here somewhere. Thank you
Approx. How much HP is gain by switching to the 620 Carb over the 590 Carb in you opinion
Husky seems to tune for 9800 rpm. Stihl seems to tune for 10,500 rpm. They both seem to cut. Is this correct? Any thoughts?
Each model is have its own "sweet" spot. This was more to show people what to listen for, and that more rpm dosent mean faster always
The 620 nozzle swap, is that the check valve nozzle ?
The 620s use a bypass nozzle too.
I swap one from a stihl/husqvarna carb
Walbro part number 86-578-1
More to the point is what octane fuel were you using & what brand of oil? Those do make a difference!
I use 40:1 amsoil dominator.
I did not switch fuel/oil for this test. But I might try testing some different combinations in the future.
Man I'll pay you to teach me how to port a saw well. I can come by on weekends. 🤞
Send me an email
Hmwfllc@gmail.com
the video was excellent, I have been playing the carbs on my homelites just to get the feel and still struggle a bit, could you go more in depth on how to set the idle with the idle screw and L screw because I have an echo cs800p that doesn't like to idle when warmed up, cold no problem.
thank you again, Josh
If it starts well cold, raise the idle up a bit. May be a little high while cold but should settle in nice once warmed up.
Have you ever seen a saw “Diesel” after hitting the kill switch? What would cause that?
Too much timing, running too hot lots of compression. Or funny fuels lol
372 xp oe 13200 rpm max ok?
Was that with stock muffler/deflector?
Yes, muffler was 100% stock. Only thing I changed was added the 620 carb
🇺🇸👍🏼👍🏼
Identifing Welch plate issues
Think tinman could do with some insight on the 590, having a little trouble seems you know how they tick👌. Be interested what a dolly 79er runs on the dyno... very comparable to a 500i, yet I reckon they have more grunt ... obviously injection shit not doing a great deal if I'm being honest. can't beat a simple carb😂
I try to help anywhere I can. Just have to ask.
Stay tuned, working on some pretty exciting Dolmar/Makita stuff.
@@dynojoemods2764 sweet👌... definitely subed. That dyno stuff is awesome👍
Help me out: I’ve got a vintage Husqvarna 380CD with a Tillotson HS 123 or 160 something. On the port side of the saw as the operator would view there’s the L and H jet holes, and in that order left to right. On top of 5he carb there’s a steel sleeve leading to a spring loaded needle wi5h flathead screw. I had trouble getting the saw o start and keep running so I turned ALL 3 to 0 and then followed Tillotson manual recommendations. Saw was running waY TOO FAST AND HIGH. I was tinkering with spring loaded too screw and it really opened up so I had to screw it back near 0. Is that just the fuel needle inlet? If so, how is that different from the T idle screw on a Stihl? . Right now the saw is just running too hot. Should I just almost totally seat the top screw and do 1/8 adjustments on the L and H jets? Someone? Anyone?
The top one with the spring is the idle screw. It sounds like thst one needs a few turns out "loosen" and the idle speed should lower. Then fine tune the H, L once You get a normal steady idle
@@dynojoemods2764 woah! I get a reply from the Living Legend! Thanks so much my friend. Love your channel and your shop btw. You the man
Dyno: for the old Husky 380 CD 77cc is normal idle about 2,000?
Can you put a autotune carb on a 450 rancher?
Anything is possible. But that would probably be a pretty big task. Not sure how close the 550 coil, carb and flywheel are to fitting the 450 chassis
@@dynojoemods2764 at that point mise well just buy a 550 cause the carb alone is $100+
doesn't that saw have a limited ignition?
Yes it does, it is limited around 13.5k if you look at the small tach it hardly goes over 12.3k max.
Tight muffler and ports will not allow it to hit the limiter "stock"
@@dynojoemods2764 so if you ported that saw would you be able to get that kinda RPM out of it? I know there’s not really a need to I was just curious if it’s possible
@@steelcityperformancesaws
Yes it would hit it ported, with the nozzle swapped in the carb. The last one I ported was right at 6.2 hp at 9800 rpm. Tuned real well just below the limiter. But would hit it safely
Weird carb to tune stock. New check valve without the bypass should be mandatory for piece of mind.The 590 makes a great firewood saw.Also noodles nice without clogging.
how is it rich only 1 turn out?
These 590/620 saws run odd settings.
@@dynojoemods2764 Cool! Thanks for the reply man. Just used to Stihl I reckon. Picked up a new ms661 carb, doing some research for carb adjustment. Need to change this awful oem filter. No interest in muffler mod or porting yet. Just want a long lasting safe setup.
Where are you located at?
Michigan
Do people ever bug you to put their bicycle engines on the dyno, lol
I’ll send you $ for fuel, oil, and time to compare rich and lean oil mixes.
We might be able to get to oil tests...
Yuck. That don’t sound right at all.