I’m sorry if I triggered anybody with my terminology I kept calling it a camshaft when in fact it is called a cam gear sorry for any miscommunication y’all have a good day
You could give some people 100 bucks and they would bitch that it wasnt 2 50's. You will always piss some people off in this world no matter what you say or do...Screw'em and keep doing your thing and pay'em no attention.
No problem, could a lathe owner turn you a pair of pins turned to the dimensions of you worn bores, they would have a slight step but would be a lot tighter?
I didn't see the comments you're referring to so I cannot speak to that. I do agree that using the correct terminology is important. For accuracy and clarity but also having the correct part name is very helpful when sourcing parts and doing further research. Of course, every situation is different but in general, I advocate for that if possible. This is a matter of discourse that should easily be covered matter of factly and not involve triggering anyone. Respectfully give your concern and the reasons why. The goal should be facts and accuracy. The content of this video is great to know. Thank you for bringing it to light. I imagine the same applies to the BR series blowers?
@@newcoyote aslong as it is a 4 mix. (Super Easy to pull if valves are adjusted correctly and sonds like a 4 stroke dirt bike and doesn't idle like a old boat motor )
Sure appreciate this info! I had one come into my store for repair today. My manager told me to fix it under warranty. (didn't use 4mix. fuel was blue. I have no idea what kind of fuel additive he used but it sure locked that piston on the connecting rod.) I have had no Stihl class on this unit, but you sure pulled me our of a spot with your sessions on this unit. Thanks a lot!
this is a superb video, thank you from the UK. One of the weaknesses of the 4 mix design.... the carbs are also a pain the the ****..... once they are blocked it's sometimes impossible to unblock them as the block is in minute channel that you cant access ...cleaner or air just doesn't do it... in fact air sometimes makes it worse!
@@THEMOWERMEDIC1 they're all Husqvarna. I run Stihl commercially including 4 mix and have probably 1000 hours on my trimmer motor and it's perfect. Take care of your stuff.
new faceplate and gear as often as viable, if you keep the play in the plate end as low as possible its not going to wallow out the block end. seems to be the only mitigator, or redesign with harder bushes or even a bearing- never ha to work on one but theres a market for a case plate thats way thicker , stiffer and carries a longer shaft in a bearing.
Seen a Stihl BR600 backpack blower break a valve. The valve broke off and got stuck in the top of the piston. Was still under warranty so we put a short block in it. Owner said he had it full throttle and it just stopped. Said it damn near jumped off his back.
Man this is an OLD issue they had onnthe FS90, 100, 110, 120, and 130 engines. We replaced hundreds of short blocks under warranty back in the 2007 to 2014. I haven't seen one of these failures in about 8 years now.
I think the solution for the "4-Mix" is to put the best air filter possible on it. An engine that always gets new oil, rather than recirculating contaminated oil should theoretically last for ever. The only source of particulate matter, is through the air intake. Maintaining proper valve clearance is also a good idea. (to protect the cam gear) This is a fascinating engine, I'm interested in getting a leaf blower or something that uses this engine, just so I can experiment with it.
The simplest fix for those pin seats that have gone oval is a suitable strip of copper or steel tubing from a refrigerator or air conditioner. Put in the pin, tap in the suitable sized tubing strip to fill up the oval and apply a teeny bit of super glue to the body and tubing to hold them together. Then remove the pin. In the first stage of wear the pin seat on the engine block for the cam wheel and the pin seat on the for the rocker arms are what wear out. Detectable at an early stage by a varying valve clearance at every rotation of the crankshaft. Now, the key question, does this fix work. Well, i started doing this in 2003 and have never had any issues.
I have run into this on a 4 cycled tree Pole saw. New engine time I couldn't see a cheap fix..thanks for that information. Now I can justify to my boss what happened.
I just bought a new stihl weed trimmer a few days ago fs 70r I was looking at the 91r but after seeing all the issues with the 4 mix engine I decided to get the 70r 2 stroke for life when it comes to weed trimmers leaf blowers edgers pole saws etc my new 70r will never see ethanol.People don't understand when you use feul with ethanol in it when you let your equipment sits the gas separates and sits on top where the ethanol sits on bottom where the feul line sits with the little filter attached so when you start your equipment it see's nothing but ethanol with very little lubrication ethanol kills small engines.
@@snoopfurlow1275which stihl is a 2 stroke? When I emailed them stihl replied pretty much everything was 4 mix and only pure 2 strokes they had were a few pressure washers
Good information to know, thanks for sharing! I have a Stihl BR600 backpack blower which has the 4 mix, I actually bought it used from a lawn care service real cheap because it didn't run. Looks like it's got some hours on it since it was used commercially, got it running and luckily it's been great and reliable, haven't had this issue yet.
Oil lite bush is the real option new block leaves you in the same boat whereas a bush will last basically forever you could do the mod yourself with a decent drill stand and the right size milling cutter njt a major problent for a decent mechanic .
Great video 4 mix are great engines like anything they need to be taken care of not beat to death l only had one problem in twenty years one engine dropped a valve and it was short blocked under warranty take care my friend 😊
Very, very good.......and that's why I avoid buying any Stihl stuff with the 4Mix engine. My dealer told ne about the horrible problems he had with the 800 backpack blower so I got the Husqvarna 580 with the Zenoah engine instead -Very noisy but fantastic and ultra reliable with no valves adjustment problems.
I've seen some of those cam gears melt and others that wallow out the hole in the engine block and others that wear down the cam lobe but never seen one do this.
These are good engines when used and maintained properly, the problem is operators abuse them and mechanics dont understand or want to maintain them, all at the detriment to the engine, I am a stihl tech btw
JB weld to the rescue. it works just fine, just brake cleaner it down first. it really isn't worth using anything else. and yeah, ASE certified, recertified,master technician.
Thanks for very useful video @themowermedic1. There is actually one mistake - the pin wobble you show at 3:28 seems to be totally normal. I have had a catastrophic cam failure - melted palstic, metal back plate disintegration etc and when replacing I checked the pin and had the same wobble as shown in your wideo at 3m:28s.. So I ordered a new cover and it has exactly the same amount of play in it. I guess this is a design feature to facilitate refitting the cover which might be very difficult if all the holes where machined to very tight tolerances. The hole the pin goies into in the engine block is very tight and hence the cam followers are very stable.
How tight are those shafts really going to be when sitting in just one shallow boss? I'm not sure you'd see that play with the shaft sitting in both bosses. The plastic cam gear with thin backing plate are far weaker than those shafts or the holes they go into. The 4 mix require more maintenance than a 2 stroke, but the power/lower fumes is well worth it. You couldn't pry my fs111 or fs131 out of my hands.
First, I'm not a landscaper, I'm a contract poultry producer. I have allot of buildings to keep trimmed and mowed around on the farm. I have three Stihl's, a FS 130, FS 110 and a FS 90. The 130 and the 110 are the oldest (6-7) years old. I've lost compression with the 130 before and was told to fill the cylinder with Seafoam for a few days and it would dissolve some of the carbon. It worked and the machine worked for about 6 months. Now, both the 110 and the 130 are down again with low compression. I tried the Seafoam trick again with no success. These machines were run using Stihl synthetic 2 stroke oil. About a year ago I changed over to Echo Red Armor oil at the recommendation of a"Chickanic" and the difference was remarkable. The machines run better, consistency. What is causing this issue and what can I do. to resolve the problem? I live in a very rural area of coastal NC and we don't have a very good selection of small engine mechanics.
Not sure if you've gotten an answer yet, but are you half-throttling them, or using them for relatively short periods of time? If you don't get them up to temperature you get incomplete combustion and they foul up, is what I would assume is the root cause of your carbon issue. Echo red armor is just really good oil and has a detergent package to keep the engine cleaner. Assuming you've checked all the obvious things (fuel, air, spark), unhook your spark plug, take the plastic off and take the valve cover off. Spin it over with the rope and make sure you don't have a valve hanging up as it's trying to close or a broken spring. bring it to TDC on compression and make sure valve clearance is correct - this can be done with a basic feeler gauge. Clearance spec will be in your owners manual. If this doesn't work, you can run a leakage test and figure out where the compression is leaking from.
There is some dirty tricks you can do to your own stuff, like drilling out a slightly larger bore and using a rod that fits perfectly. None of the dirty tricks are something I would trust handing to a customer with any for of warranty on the repairs, so block replacement is the only "safe" bet.
Great video bro very helpfull thank you . I have the exact same problem with the rocker arm pin on the cam plate cover being wallowed out . I will replace the cam cover asap . The cam gear pin hole on the engine is slightly wallowed out too but not as bad as the example you show here . Do you think the engine is still ok with the slight play on the cam gear pin hole on the engine block ? Thank you kindly
There's got to be owner issues. I have a first or second production run BR600 and I've been in this engine twice. The second time was to replace the cam gear. The back plate on the cam gear had become lose. I noticed it while adjusting the valves. The mechanism in the cam gear is for start up decompression...RPM over rides it. I have a lot of hours on this blower and it shows no wear in the ares you''re pointing out. IMO...it's not an engine issue....it's an owner/operator issue.
Hey GREAT video- a question my FS310 gradually lost compression today!! weird thing is the cam lobe had melted to nothing and with the cam and rockers removed it STILL has no compression!! its not done big hours and it was running perfectly then lost power and revs (and compression!) over a 1 minute period - what could it be. blown valve?
Hi I have a BR800 that may not be fixable. It too had loose sockets. I tried peening the shoulders of the loose sockets. I then cleaned up the peening pits with 220 sandpaper. The pins are much tighter now. I have a piston on order so can’t tell whether this will help yet.
Hi there! My father lives in cuba and he uses this to mow the grass for work, they do not have any lawn mowers so this is better than a machete. He says the big piece that you called engine block broke on his weed eater from 2012. He didn’t know the English name for it, he just sent me a picture. Your video is the only one I have seen with the actual piece. It’s the one that the pins go in at the end of your video. Could you tell me the name of that piece? I need to see if they even sell them to send it to him. Thanks so much!
I’m going to look through your videos, but do you have any covering a cylinder replacement on this engine? Have a stripped spark plug hole on my FS90 and about to start tearing the engine down to replace it. This video helped me get an idea of the cam setup prior to pulling it apart.
I posted this a while back. But yes, I could have done a heli-coil. However, no shops around me would do it. For me to buy the helicoil kit and appropriate size thread insert, it would have been about $100. For $120 I got a brand new cylinder/piston assembly. These videos did help me piece together what I’d see when I pulled it apart. Was a super easy repair in the end.
Thanks for the video. I have not ran across any yet. Since that's a problem and most choose not to repair them I'm sure I'll end up with one eventually. Does the pins rotate in the bosses? Or the gears around the pins? Thanks
@@THEMOWERMEDIC1 Yes, they made this too simple for cheap labor and material costs. The pins would best be hardened ones threaded into the main case with a shoulder to keep it tight against the main case.
I have one and it won’t rev. Valve adjustment done. New fuel lines, filter and tank vent. Starts easy and idles good but won’t rev at all. Throttle cable good. Any suggestions??
The design is actually great...the materials used could be better. I have the fs111 and fs131...I'd have a hard time parting with them, the power and response is great.
so once it gets to this point, sell it in a yard sale and buy a new one? have a small collection of all stihl weedeaters, all have a lot of mileage and have issues. i only keep my FS240r in working order cause i havent needed to go to a backup weedeater until lately. we have 2 small residential stihl weedeaters plus an fs90 that hasnt ran in years and was wondering if it was worth it to get it back in working order. but after this video i think its not worth it, sell it at the yard sale. btw the fs240r still runs beautifully IF you can keep it servcied
You don't understand.A 4 mix engine is a 4 stroke that must be run on at least 50 to 1 fuel oil ratio same as a 2 stroke as the engine has no oil in it for lubrication purposes.In other words a 4 stroke that must have it's fuel mixed like a 2 stroke.
Someone please comment regarding the advantage that this hybrid 4mix engine has over the traditional refined 2-stroke counterpart. I'm completely stumped.
@@leifvejby8023 Yes, interesting side note: In the late '70s and early '80s, four cycle model aircraft engines came on the market. I bought two of the first ones and competed in the '82 U.S. national contest with an RC Stearman biplane in a scale class and won with a .40 cubic inch four stroke engine. Most noticeable was the huge reduction in noise which I know counted in my favor. The sound it did make was much more in the character of the airplane than the usual two stroke.
@@whalesong999 I remember, I still have four OS 20FS somewhere, that I bought for a Focke Wulf Condor. They run great and are very quiet even without mufflers. No, I never came around to actually building it, but some day!
@@THEMOWERMEDIC1 it may be true that alot of electric stuff is junk, however this vid proves that some 4 stroke stuff can also be considered junk. Same goes for the majority of 2 stroke stuff out there today. The problems associated with this particular engine could have been alleviated if the engineers were allowed to bush those shafts and not be forced by the accountants to save a few nickles. The same goes for 2 stroke junk being made in china to serve the same purpose of saving those few precious nickels. The internal combustion engine has, thru ecology and basic economics, run its course. Electric is just starting to ramp up and soon will prove to be more powerfull and more economical than engine power, plus it can be refueled(charged) while you do something else like drive to the next jobsite. No more having to fill equipment before starting work, hard to start , going to gas station, all of which now becomes time working with less overall stress. I think its Electric for the win , if we keep china out of the picture
My god what in the world is this person running for oil in the gas? Outboard motor oil or what. Iv e worked on stihl's that are old and they are not that dirty! Wrong oil will cause overheating or to little will cause it too!
I’m sorry if I triggered anybody with my terminology I kept calling it a camshaft when in fact it is called a cam gear sorry for any miscommunication y’all have a good day
We know what you meant.Good vid,keep em comming.
You could give some people 100 bucks and they would bitch that it wasnt 2 50's. You will always piss some people off in this world no matter what you say or do...Screw'em and keep doing your thing and pay'em no attention.
No problem, could a lathe owner turn you a pair of pins turned to the dimensions of you worn bores, they would have a slight step but would be a lot tighter?
I didn't see the comments you're referring to so I cannot speak to that. I do agree that using the correct terminology is important. For accuracy and clarity but also having the correct part name is very helpful when sourcing parts and doing further research. Of course, every situation is different but in general, I advocate for that if possible. This is a matter of discourse that should easily be covered matter of factly and not involve triggering anyone. Respectfully give your concern and the reasons why. The goal should be facts and accuracy. The content of this video is great to know. Thank you for bringing it to light. I imagine the same applies to the BR series blowers?
@@newcoyote aslong as it is a 4 mix. (Super Easy to pull if valves are adjusted correctly and sonds like a 4 stroke dirt bike and doesn't idle like a old boat motor )
Probably the best close up videos to help diagnose and fix similar trimmers
Sure appreciate this info! I had one come into my store for repair today. My manager told me to fix it under warranty. (didn't use 4mix. fuel was blue. I have no idea what kind of fuel additive he used but it sure locked that piston on the connecting rod.)
I have had no Stihl class on this unit, but you sure pulled me our of a spot with your sessions on this unit. Thanks a lot!
this is a superb video, thank you from the UK. One of the weaknesses of the 4 mix design.... the carbs are also a pain the the ****..... once they are blocked it's sometimes impossible to unblock them as the block is in minute channel that you cant access ...cleaner or air just doesn't do it... in fact air sometimes makes it worse!
So, stay away from the 4 mix engine then. Got it. Thanks for the info.
4- Mess ... I fixed mine for good. It’s called Redmax and Shindiawa.
Shindiawa is echo. Good choice 👍
I pitched mine and went Shindaiwa too. Runs great! My Stihl was garbage out of the box.
What a shitty flimsy set up. I will stick with the 2 stroke. Never have much in the way of issues with them
@@THEMOWERMEDIC1 they're all Husqvarna. I run Stihl commercially including 4 mix and have probably 1000 hours on my trimmer motor and it's perfect. Take care of your stuff.
Had the same problem on Briggs motors. I have to hold a piece of foam over the carb to create a vacuum to spin the motor
I've seen this exact thing several times before. Melted cam, wollowed out front and rear cam pin holes. Big mess. Not a big fan of the 4 mix.
See it every day
Good Vid! Steel into aluminum never good. You know what the fix is for this? Echo!
new faceplate and gear as often as viable, if you keep the play in the plate end as low as possible its not going to wallow out the block end.
seems to be the only mitigator, or redesign with harder bushes or even a bearing- never ha to work on one but theres a market for a case plate thats way thicker , stiffer and carries a longer shaft in a bearing.
Seen a Stihl BR600 backpack blower break a valve. The valve broke off and got stuck in the top of the piston. Was still under warranty so we put a short block in it. Owner said he had it full throttle and it just stopped. Said it damn near jumped off his back.
Never worked on one, but now I have an idea of what's going on. Reminds me of those 5hp jobs engines with one cam lob.
Man this is an OLD issue they had onnthe FS90, 100, 110, 120, and 130 engines. We replaced hundreds of short blocks under warranty back in the 2007 to 2014. I haven't seen one of these failures in about 8 years now.
I think the solution for the "4-Mix" is to put the best air filter possible on it. An engine that always gets new oil, rather than recirculating contaminated oil should theoretically last for ever. The only source of particulate matter, is through the air intake. Maintaining proper valve clearance is also a good idea. (to protect the cam gear) This is a fascinating engine, I'm interested in getting a leaf blower or something that uses this engine, just so I can experiment with it.
Lots of torque on these engines.
I want one on the next edger I buy
Thank you for this it will be a big help i dont see alot of theese at my echo dealer but i know this will help.
The simplest fix for those pin seats that have gone oval is a suitable strip of copper or steel tubing from a refrigerator or air conditioner. Put in the pin, tap in the suitable sized tubing strip to fill up the oval and apply a teeny bit of super glue to the body and tubing to hold them together. Then remove the pin. In the first stage of wear the pin seat on the engine block for the cam wheel and the pin seat on the for the rocker arms are what wear out. Detectable at an early stage by a varying valve clearance at every rotation of the crankshaft.
Now, the key question, does this fix work. Well, i started doing this in 2003 and have never had any issues.
I have run into this on a 4 cycled tree Pole saw. New engine time I couldn't see a cheap fix..thanks for that information. Now I can justify to my boss what happened.
Me gusta tu vos tu actitud para mostrar los problemas es relajante ver. Saludos desde Dallas TX
Good Job buddy like always you have teach me so much now I do my own small engine repair your the man
I just bought a new stihl weed trimmer a few days ago fs 70r I was looking at the 91r but after seeing all the issues with the 4 mix engine I decided to get the 70r 2 stroke for life when it comes to weed trimmers leaf blowers edgers pole saws etc my new 70r will never see ethanol.People don't understand when you use feul with ethanol in it when you let your equipment sits the gas separates and sits on top where the ethanol sits on bottom where the feul line sits with the little filter attached so when you start your equipment it see's nothing but ethanol with very little lubrication ethanol kills small engines.
Stay away from the 4 mixes,I had 2 that had the same problems,I upgraded to a Stihl km 2 stroke, problem solved
@@snoopfurlow1275which stihl is a 2 stroke? When I emailed them stihl replied pretty much everything was 4 mix and only pure 2 strokes they had were a few pressure washers
I love my Honda 35 - a bit on the heavy side, but gobs of torque - I call it my hand-held Massey-Ferguson...
Good information to know, thanks for sharing! I have a Stihl BR600 backpack blower which has the 4 mix, I actually bought it used from a lawn care service real cheap because it didn't run. Looks like it's got some hours on it since it was used commercially, got it running and luckily it's been great and reliable, haven't had this issue yet.
Oil lite bush is the real option new block leaves you in the same boat whereas a bush will last basically forever you could do the mod yourself with a decent drill stand and the right size milling cutter njt a major problent for a decent mechanic .
Great video 4 mix are great engines like anything they need to be taken care of not beat to death l only had one problem in twenty years one engine dropped a valve and it was short blocked under warranty take care my friend 😊
Just started watching your videos and can’t tell you how much I appreciate learning from you. Subbed. Thanks!
Glad I pitched my 4 mess. My new Shindaiwa is running nice.
Very, very good.......and that's why I avoid buying any Stihl stuff with the 4Mix engine.
My dealer told ne about the horrible problems he had with the 800 backpack blower so I got the Husqvarna 580 with the Zenoah engine instead -Very noisy but fantastic and ultra reliable with no valves adjustment problems.
JB WELD THE SHAFT AN SAND DOWN TOO FIT.
I would fit in brass bushes or roller bearings race. 😳
Good tip. Make a video of that and post it here when you upload. We would love to see it
Great video, the Epa strikes again, another reason why I love my Stihl and Echo 2 strokes.
Hey man love your videos can you do a video on how to adjust the carbs on the stihls
I've seen some of those cam gears melt and others that wallow out the hole in the engine block and others that wear down the cam lobe but never seen one do this.
Way To Go Double M.This Is
Awesome Information.Richard.
Many thanks for sharing your knowledge.
These are good engines when used and maintained properly, the problem is operators abuse them and mechanics dont understand or want to maintain them, all at the detriment to the engine, I am a stihl tech btw
All the videos show how to repair but no one tells you what oil going in the engine 😅
JB weld to the rescue. it works just fine, just brake cleaner it down first. it really isn't worth using anything else. and yeah, ASE certified, recertified,master technician.
Funny - I was thinking the exact same thing
Or, hear me out, do the correct repair.
@@blakegrubb3091 When you need a new block already, what exactly do you have to loose?
I dont think jbweld would handle a hot pin rotating at speed in an oily environment
Thanks for very useful video @themowermedic1. There is actually one mistake - the pin wobble you show at 3:28 seems to be totally normal. I have had a catastrophic cam failure - melted palstic, metal back plate disintegration etc and when replacing I checked the pin and had the same wobble as shown in your wideo at 3m:28s.. So I ordered a new cover and it has exactly the same amount of play in it. I guess this is a design feature to facilitate refitting the cover which might be very difficult if all the holes where machined to very tight tolerances. The hole the pin goies into in the engine block is very tight and hence the cam followers are very stable.
Be sure to order the newest part number backing plate. The old part number has play, and the new part number with the oil dam has no play
Yes that info was spot on for my trouble , Thank u brotha
Glad I could help
Had Honda 4 stroke strimmer 13 years no problems
A little bit in a machining couple bushings Good2Go
Make a video of that and send me a
Link when you get it uploaded
I doubt if I would ever own one of these engines but that is a neat engine. Thanks for the video and I will share with others.
I have a fs90. It's like this. I love it. Had it for years and never done a thing to it. Sits outside 24/7 for years now and always starts and goes
Think there's one thing missing, how to prevent this type of wear? :)
Mine went bad but intermittently worked...a tab of that stamped piece broke off and found its way through the intake valve.
How tight are those shafts really going to be when sitting in just one shallow boss? I'm not sure you'd see that play with the shaft sitting in both bosses. The plastic cam gear with thin backing plate are far weaker than those shafts or the holes they go into. The 4 mix require more maintenance than a 2 stroke, but the power/lower fumes is well worth it. You couldn't pry my fs111 or fs131 out of my hands.
First, I'm not a landscaper, I'm a contract poultry producer. I have allot of buildings to keep trimmed and mowed around on the farm. I have three Stihl's, a FS 130, FS 110 and a FS 90. The 130 and the 110 are the oldest (6-7) years old. I've lost compression with the 130 before and was told to fill the cylinder with Seafoam for a few days and it would dissolve some of the carbon. It worked and the machine worked for about 6 months. Now, both the 110 and the 130 are down again with low compression. I tried the Seafoam trick again with no success. These machines were run using Stihl synthetic 2 stroke oil. About a year ago I changed over to Echo Red Armor oil at the recommendation of a"Chickanic" and the difference was remarkable. The machines run better, consistency. What is causing this issue and what can I do. to resolve the problem? I live in a very rural area of coastal NC and we don't have a very good selection of small engine mechanics.
Not sure if you've gotten an answer yet, but are you half-throttling them, or using them for relatively short periods of time? If you don't get them up to temperature you get incomplete combustion and they foul up, is what I would assume is the root cause of your carbon issue. Echo red armor is just really good oil and has a detergent package to keep the engine cleaner. Assuming you've checked all the obvious things (fuel, air, spark), unhook your spark plug, take the plastic off and take the valve cover off. Spin it over with the rope and make sure you don't have a valve hanging up as it's trying to close or a broken spring. bring it to TDC on compression and make sure valve clearance is correct - this can be done with a basic feeler gauge. Clearance spec will be in your owners manual. If this doesn't work, you can run a leakage test and figure out where the compression is leaking from.
Now that is some straight up no bs good info to have.
There is some dirty tricks you can do to your own stuff, like drilling out a slightly larger bore and using a rod that fits perfectly. None of the dirty tricks are something I would trust handing to a customer with any for of warranty on the repairs, so block replacement is the only "safe" bet.
A dirty cooling system causes most of the over heating problems along with ethanol blended fuels.
Incorrect. Lean fuel conditions and no guard “line too long” are the causes of overheating
I've thrown out more of those engines then I can count. most of them over 10 to 12 years old. running all day long.
Over here in Scotland She's a fekin bin job, cheapest repair is replace the motor especially when you can get a chow mein motor for about 30 bucks.
This is great info thank you!!
Great video bro very helpfull thank you .
I have the exact same problem with the rocker arm pin on the cam plate cover being wallowed out .
I will replace the cam cover asap .
The cam gear pin hole on the engine is slightly wallowed out too but not as bad as the example you show here .
Do you think the engine is still ok with the slight play on the cam gear pin hole on the engine block ?
Thank you kindly
There's got to be owner issues. I have a first or second production run BR600 and I've been in this engine twice. The second time was to replace the cam gear. The back plate on the cam gear had become lose. I noticed it while adjusting the valves. The mechanism in the cam gear is for start up decompression...RPM over rides it. I have a lot of hours on this blower and it shows no wear in the ares you''re pointing out. IMO...it's not an engine issue....it's an owner/operator issue.
Good to know video!! Thanks.
No they don't...too many over them are bolts & nuts level & claim they are higher,is why lol.
Video explains the rest,top job 👍
Just watching this because my friend taryl sent me the root cause is because win you mix plastic with metal this will always happens no doubt
Hey GREAT video- a question my FS310 gradually lost compression today!! weird thing is the cam lobe had melted to nothing and with the cam and rockers removed it STILL has no compression!! its not done big hours and it was running perfectly then lost power and revs (and compression!) over a 1 minute period - what could it be. blown valve?
Hi
I have a BR800 that may not be fixable. It too had loose sockets. I tried peening the shoulders of the loose sockets. I then cleaned up the peening pits with 220 sandpaper. The pins are much tighter now.
I have a piston on order so can’t tell whether this will help yet.
Great video
Hi there! My father lives in cuba and he uses this to mow the grass for work, they do not have any lawn mowers so this is better than a machete. He says the big piece that you called engine block broke on his weed eater from 2012. He didn’t know the English name for it, he just sent me a picture. Your video is the only one I have seen with the actual piece. It’s the one that the pins go in at the end of your video. Could you tell me the name of that piece? I need to see if they even sell them to send it to him. Thanks so much!
Sorry just so you know the piece he says he needs is the entire part at the end that has 4 screws. Sorry it’s hard to figure this out lol.
Great information!
Replace the journal rods, lightly bore the journals and insert bushings, replace cam gear.
Where do you get the bushings from?
@@japerezo75 If you can't find something already in the size needed, might have to have some made.
Gotta love the smell of a 2 smoke in the morning!!!!
Great video. What can you do to prevent this from happening.
Don’t bog the engine
I’m going to look through your videos, but do you have any covering a cylinder replacement on this engine? Have a stripped spark plug hole on my FS90 and about to start tearing the engine down to replace it. This video helped me get an idea of the cam setup prior to pulling it apart.
Can you not fix it with a heli-coil?
Yes
I posted this a while back. But yes, I could have done a heli-coil. However, no shops around me would do it. For me to buy the helicoil kit and appropriate size thread insert, it would have been about $100. For $120 I got a brand new cylinder/piston assembly. These videos did help me piece together what I’d see when I pulled it apart. Was a super easy repair in the end.
Never did like the 4 mix engines
Thanks for the video. I have not ran across any yet. Since that's a problem and most choose not to repair them I'm sure I'll end up with one eventually. Does the pins rotate in the bosses? Or the gears around the pins? Thanks
The pin is free to rotate, and I think that is part of the problem
@@THEMOWERMEDIC1 Yes, they made this too simple for cheap labor and material costs. The pins would best be hardened ones threaded into the main case with a shoulder to keep it tight against the main case.
@@whalesong999 or staked in
I have one and it won’t rev. Valve adjustment done. New fuel lines, filter and tank vent. Starts easy and idles good but won’t rev at all. Throttle cable good. Any suggestions??
the more I see of these 4 mix engines , the less likely I am to buy one.
There is a solution to all these little parts that are prone to failure. It's called a two stroke.
Why don’t you like the 4mix in general?
Well, that looks like a horrifically shit and needlessly complicated design implemented in plastic and pot metal.
The design is actually great...the materials used could be better. I have the fs111 and fs131...I'd have a hard time parting with them, the power and response is great.
Maybe, but it still gives less problems than the average 2stroke. And it isn't pot metal, it is a metric metal named aluminium alloy.
Excellent video 👍
Drill holes out to next shaft size
whats the part number for the stihl km 131 short block
so once it gets to this point, sell it in a yard sale and buy a new one? have a small collection of all stihl weedeaters, all have a lot of mileage and have issues. i only keep my FS240r in working order cause i havent needed to go to a backup weedeater until lately. we have 2 small residential stihl weedeaters plus an fs90 that hasnt ran in years and was wondering if it was worth it to get it back in working order. but after this video i think its not worth it, sell it at the yard sale. btw the fs240r still runs beautifully IF you can keep it servcied
What’s a yard sell?
@@THEMOWERMEDIC1 sell/sale i cant spell too good
@@THEMOWERMEDIC1 a worn out fs90 worth keeping or get rid of it in a junk/garage sale?
how long you think it would last if you just put a new cam in there?
The slop wont allow the valve adjustment to stay true
Do you do much Honda gx25 / gx35 line trimmer repairs? Do people in your area use Honda small equipment
Mine turns over but it’s extremely hard to pull
How can I contact you directly on your expertise on this engine design?
So what is causing this? Lack of oil change?
Design flaw
You don't understand.A 4 mix engine is a 4 stroke that must be run on at least 50 to 1 fuel oil ratio same as a 2 stroke as the engine has no oil in it for lubrication purposes.In other words a 4 stroke that must have it's fuel mixed like a 2 stroke.
@@eugeneoreilly9356 I understand just fine
@@THEMOWERMEDIC1 the reply was to the op that thinks that you change the oil in a 4 mix like a normal motor with oil pan .
Interesting, thanks👍
Primary cause of this problem is lack of maintenance
Thanks 😊
Can l put some oil on the block or don't used oil😢
Huh?
What does short block mean ?
Thanks
We like our 18V Milwaukee string trimmer
It would run out of battery before I could finish weed trimming my 1.2 acres
@@THEMOWERMEDIC1
Yes the gas ones have there place too
Gracias
It happens after several hundreds hours and over heating
Enjoying my echo
As a motorcycle mechanic I'm watching this like duhhh
Then don’t watch🤷 move on along
Someone please comment regarding the advantage that this hybrid 4mix engine has over the traditional refined 2-stroke counterpart. I'm completely stumped.
More power and torque is the
Main thing
Thermal efficiency, they burn the fuel mix more completely than a two stroke does, hence cleaner emissions.
The above plus a less annoying noise
@@leifvejby8023 Yes, interesting side note: In the late '70s and early '80s, four cycle model aircraft engines came on the market. I bought two of the first ones and competed in the '82 U.S. national contest with an RC Stearman biplane in a scale class and won with a .40 cubic inch four stroke engine. Most noticeable was the huge reduction in noise which I know counted in my favor. The sound it did make was much more in the character of the airplane than the usual two stroke.
@@whalesong999 I remember, I still have four OS 20FS somewhere, that I bought for a Focke Wulf Condor. They run great and are very quiet even without mufflers. No, I never came around to actually building it, but some day!
These 4 mix engines aren't a good idea , their a rubbish idea ,stick to a good 2 stroke every time
Wont be any two strokes soon. EPA wants everyone to own electric junk
Stick to the gx25/35 legit 4 strokes and the Makita 4 cycles
@@DeliciousBass01 too heavy
@@THEMOWERMEDIC1 agree if you run them all day. Im not a professional, i just spend money on quality stuff :)
@@THEMOWERMEDIC1 it may be true that alot of electric stuff is junk, however this vid proves that some 4 stroke stuff can also be considered junk. Same goes for the majority of 2 stroke stuff out there today.
The problems associated with this particular engine could have been alleviated if the engineers were allowed to bush those shafts and not be forced by the accountants to save a few nickles. The same goes for 2 stroke junk being made in china to serve the same purpose of saving those few precious nickels.
The internal combustion engine has, thru ecology and basic economics, run its course. Electric is just starting to ramp up and soon will prove to be more powerfull and more economical than engine power, plus it can be refueled(charged) while you do something else like drive to the next jobsite.
No more having to fill equipment before starting work, hard to start , going to gas station, all of which now becomes time working with less overall stress. I think its Electric for the win , if we keep china out of the picture
50% is awful generous.
My god what in the world is this person running for oil in the gas? Outboard motor oil or what. Iv e worked on stihl's that are old and they are not that dirty! Wrong oil will cause overheating or to little will cause it too!
Stihl ultra hp
I’m going to agree with Tom, I’ve been a Stihl dealer for 37 years, I’ve never seen a Stihl 4MIX run on ultra that looks like that inside.
@@matthewlozosky1028 then you fit within the 50%
All that black inside the engine, it looks like it was running too hot.
I want to like sthihl but echo is better and much easier and cheaper for maintenance
Why not get the old pieces rebushed? They would be way better. I mean the warrantied old pieces.
Those 4 mix engines are junk anyway.No advantages whatsoever.Extra complexity and no power.Wouldnt take one for free.
JB Weld to the rescue