STIHL FS 91R has major engine failure / Also FS 91 common problems
HTML-код
- Опубликовано: 16 дек 2023
- Customer brought in a FS 91 that died on them while in use. I discover a major engine failure after an inspection and teardown. I also briefly discuss some common problems with these units.
#stihl #enginefailure #smallenginerepair
I have a 91 and 131 r. Not a single issue. Allot these issues come from operator abuse. Bad gas, not letting the unit cool down, lack of maintenance, etc.
Bad gas? You shouldn't run gas with ethanol and mixed right, if it still runs like crap the dang venders will tell you to buy the ten dollars for a small can of gas to make it run nice, now that pisses me off big time and it should tick everybody off especially if they use more then a gallon a week for their trimmers, nobody can afford that shit.
Nice autopsy! Good to see those failure points.
Thank you Wollys Workin,
the damage pattern may have been the result. The piston is at the exhaust top dead centre and it had a mixture of approx. 1.14 to 1.16 due to a fuel problem and was therefore running in the range of the highest combustion, piston and slightly too low cylinder temperature. Piston too big, too hot. It could have burnt back into the crankcase with high overpressure under the piston. Ignited via the piston rings, which were far too hot. Thanks for the nice video.
Another Stihl 4-Mix engine crankshaft with real shapely museum quality.
MpG.
EISENEXE
Michael Fritjof Mueller
Great video - - thanks!!
I can fix it, adjust the valve lash,,i think sthil has went down hill
When you refer to older models of the 91r with the common issues, what approximate year of these are you referring to? I’m not sure when they were first released. I have a 2019 model with a bit of vibration and tank vent issue I need to fix and came across this video. Cool and very informative video!
Looks like a combination of poor design and operator error. This is why one should read the owners manual and strictly stick the operation and fuel usage of the manual while under warranty. Following that simple guide line makes the company warranty valid no matter what. Having good employees that listen and care about their job helps as well....
You’re asking for all three sides of the triangle lol. I agree with your statement but it never happens.
We had 5 backpack blowers that came in with engines locked up. All of them was due to wrist pin failure. I wonder why Stihl didn't put a wrist pin bearing on the 550-700 blowers. It make no sense at all.
Hi speed user move force reaction.
They did open up the wrist pin clearance a few years ago, It helped but still too many issues.
@@wallysworkin823 Ok. STIHL US Get this isue here.
When I see plastic gears,cams in an engine I say 'no thanks'.
Just bought one and now thinking of returning after this video Did they warranty the unit?
It was warranty. This was a rare occasion, it’s not a common occurrence.
Piston rod bushing overheating may cause this piston damage I think
I’m glad that Stihl bought the 4- mix design from Shindaiwa before Echo bought Shindaiwa or this crap could have been on Echo equipment. It has too many failure points and moving parts that outweigh the benefits.
Shindaiwa’s C4 design wasn’t bad when Shindaiwa was Made In Japan… Echo ruined Shindaiwa. Maruyama is Made In Japan. Most Stihl products are Assembled In USA, same with Shindaiwa who no longer promotes the “First to start last to quit” slogan.
Agree,wouldn't touch those four strokes.
I just bought a 91 today should I be worried and return it before the problem arises?
I have one at work that I use 6 hours a day without stopping every single day it'll be fine I'm sure some people just get unlucky
@@evildrporkchop4628 appreciate it bro I love the weed eater it’s perfect for what I do on a daily basis compared to the 94.
@@kristiancastillo1730 I gotchu brother
Will Stihl pay for fixing it? And replace the engine?
Most likely.
Depends who you buy it from, yes they should and if you have a hard time call Stihl, ace gave me some problems with my warranty, kept telling me nothing is wrong and it's my imagination, I just about wrapped a weed whacker around his head.
All of that silicone is amazing. Looks like an amateur assembled it! And, probably did:/
Switched to shindiawa stihl not reliable anymore
I dont get why the older smaller stihls runs lots better than the new bigger ones, its ridiculous and i am not paying ten bucks for a 32 ounce can of mixed gas that they recommend that you use, im about ready to get away from stilh and looking at the ecos next time around, they have a better warranty to boost.
Warranties are pretty equal. With Stihl if you buy a gallon of their motomix they double the warranty.