Chainsaw Repair

Husqvarna - Stihl - Poulan - Jonsered - Dolmar chainsaws and more => Stihl => Topic started by: Remington on November 11, 2012, 09:45:12 pm

Title: 036 pro weak and barely going full throttle
Post by: Remington on November 11, 2012, 09:45:12 pm
Do you guys have a starting point for this problem.

O36 Pro, very hard to start, now almost impossible to start, when it does start it only runs at 1/2 to full throttle and now on the last few cuts, it was stopping the chain as soon as it hit wood.

It was ripping logs a few days ago, the problem developed over the last 2 days of light use. I doubt it lost compression in 2 days.
Title: Re: 036 pro weak and barely going full throttle
Post by: Al Smith on November 12, 2012, 09:08:11 am
It's most likely a fuel delivery problem and more than likely the carb .

There is a tiny little fine mesh  screen on the check valve side of those carbs .This mesh is the last line of defense to stop fine bits of contamination from entering the engine via the fuel .It will catch such fine stuff that can get passed the tank fuel filter .They will on occasion become plugged with stuff and make starting next to impossible .
Title: Re: 036 pro weak and barely going full throttle
Post by: Remington on November 13, 2012, 12:32:15 am
Might be a clog but not in the little screen. I took the carb apart and it was clean, I did find some dust in the lower part. I'll know tomorrow when I start it. The plug wasn't in the best condition either.
Title: Re: 036 pro weak and barely going full throttle
Post by: Al Smith on November 13, 2012, 08:55:03 am
It's possible it could be the plug but not likley .Easy enough to find out ,new plug .

Now that carb diaphragm  has to be totally supple just not only being able to expand and collapse a slight bit .If it is not it can only supply enough fuel to run at reduced speeds  . In essence the engine is over running the carb .

Speaking of carb ,the design of a diaphragm carb is really a form of an early mechanical  fuel injecter .It works just about the same way in a simplistic fashion .

It still reverts  back to a  fuel delivery problem where ever that leads IMO .
Title: Re: 036 pro weak and barely going full throttle
Post by: Remington on November 13, 2012, 12:10:30 pm
Well I got it going. I haven't fine tuned it yet but cleaning the carb and a new plug did the trick.  Thanks again.
Title: Re: 036 pro weak and barely going full throttle
Post by: Al Smith on November 13, 2012, 01:03:42 pm
Sometimes repeat "sometimes " a carb clean up works in lieu of a rebuild kit but more times not .Glad it worked out . ;D
Title: Re: 036 pro weak and barely going full throttle
Post by: Remington on November 13, 2012, 08:31:53 pm
I hate carbs.  It's the only thing I don't know about. I screwed them up on my bikes as well. Anyway it got me through the day, it doesn't feel too strong at the top end and sometimes the chain stopped when I pushed down hard enough but it runs and I'm happy.

The starting problem also cleared up. It went from about 15 pulls down 5
Title: Re: 036 pro weak and barely going full throttle
Post by: Al Smith on November 13, 2012, 09:34:03 pm
On a cold start 5 is not bad .My souped up 038 Mag it takes 10 but after that it  usually fires on one .Gives my arm some exercise so to speak .
Title: Re: 036 pro weak and barely going full throttle
Post by: Al Smith on November 13, 2012, 09:44:27 pm
Well you know do what you want but I fiddled and twittled with the carb of an s-25 Poulan today .Screwed up innards .I tried several old components to no avail just becaue I had ran out of Tillotson model HU  rebuild kits .It was a total waste of my time .I'll order 4 kits in the morning and fix it right and be done with that nonsense once and for all .

Wasted two hours over a 5 dollar rebuild kit ,must have been out of my mind .