Stihl Compression release?

[David Shelton]

I am trying to get my 1986 Stihl 038AV Super saw running after being stored for 15 or so years. After a lot of cleanup and replacing the vent and fuel hoses, it starts and runs great when it does start. What I don't understand is sometimes the starter rope is extremely hard to pull and other times it pulls and starts like it should. Is there a compression release on this saw that may not be functioning properly?

 

[rocketnorton]

no decomp on any 038

not sure bout the pull effort in your case

 

[stihltech]

Pull up to compression, then pull through. If seems to run OK, possibly some carburetor bleed through when sitting.
Also get a look at the started pulley. Not uncommon to have the old rope bind.

 

[David Shelton]

no decomp on any 038

not sure bout the pull effort in your case

Thanks, is there anything else I could look at that could make this saw extremely hard to pull?

 

[David Shelton]

Pull up to compression, then pull through. If seems to run OK, possibly some carburetor bleed through when sitting.
Also get a look at the started pulley. Not uncommon to have the old rope bind.

I have tried that but seems to still be inconsistent. Also no excessive fuel when I pull the sparkplug and pull the starter rope. Removed the starter and found it was clean and smooth with no wear marks.

 

[David Shelton]

OK. I remembered that I had bought a chicom carburetor for this saw but never usedit. Installed carb, cleaned sparkplug, and it started. Adjusted on the carb to clean it up and runs and starts good for now. Much easier to pull the rope now. I think I will order a carb kit for the original Tilly carb just in case. Thanks for all the responses that led me in the right direction.
BTW, the new carb has snorkle plate. Should I replace it with the plate off of the original carb?

 

[stihltech]

If that is the Tillotson carb with the plastic plate with the inlet needle, throw it as far as you can and forget where it is. Stihl got smart and went to regular style carbs many years ago. It solved MANY starting and running issues.

 

[ballisticdoughnut]

Installed a handful of these carbs on 038’s over the last few years. They work great and are reasonably priced. Tillotson HE-19A

 

[LarJea]

My 034 got hard to pull so I tried a Stihl Elastostart rope for a Stihl 362C, and it made all the difference in the world.

 

[David Shelton]

Starts and runs and cuts pretty good with chicom carb. Carb settings are 1 turn out on both screws. What is the best method of correctly tuning the carb?

 

[David Shelton]

Installed a handful of these carbs on 038’s over the last few years. They work great and are reasonably priced. Tillotson HE-19A

I bought one of these replacement Tilly carbs and it runs even better. The chicom carb was cheap but didn't run consistent. Thanks for the suggestion.

 

[J D]

Tom @Vintage Engine Repairs does a good tuning vid on youtube

 

[Vintage Engine Repairs]

Thanks mate!

 

[TooSoonOld]

I'm having the same issue with a Stihl MS310. When it does start, it couldn't be better. When I pull the plug, the engine turns over completely freely. Cylinder is not flooded with gas. I can't help but think there's too much compression. I would suspect plugged muffler, but then it wouldn't run so well, would it?

 

[ZeroJunk]

I'm having the same issue with a Stihl MS310. When it does start, it couldn't be better. When I pull the plug, the engine turns over completely freely. Cylinder is not flooded with gas. I can't help but think there's too much compression. I would suspect plugged muffler, but then it wouldn't run so well, would it?

No. It would not be the muffler. With a stopped up muffler the saw just would not rev up.

 

[TooSoonOld]

Thanks for confirming that. Any idea what is causing my starting problem?

 

[J D]

Check the pull start mechanism... sometimes when something isn't right in there it will bind up when under pressure but rotate freely with no load. Bearings can do the same but you'd likely have other issues if that were the case

 

[Coralillo Lo Pro]

Thanks for confirming that. Any idea what is causing my starting problem?

After going through this with different saws I say it's usually carburetor bleed. It isn't going to be so bad that you can tell it's flooded - in fact most badly flooded saws of mine pull fine. It's a slight bleed causing an excess of vapor pressure. Sounds like that's what fixed David's saw was changing out the carb, and would likely fix yours. I have a 361 I rebuilt that's near impossible if I don't pull from TDC, and it's not excess compression. Am near certain it's carb bleed but don't use it enough to be bothered changing out the carb yet, and can get it started as long as I rotate to TDC each time. Looking back at 20 years of suggestions on these kinds of posts, people guess everything under the sun but carb bleed a lot of the time. Like JD says though, I have had bad pull start mechanisms on occasion too binding things up.

 

[SteveSr]

Thanks for confirming that. Any idea what is causing my starting problem?

It could also be ignition firing too early and trying to fire backwards. To rule this out try pulling it with the ignition switch off. If it pulls fine with the switch off start looking at the ignition.

 

[president]

If that is the Tillotson carb with the plastic plate with the inlet needle, throw it as far as you can and forget where it is. Stihl got smart and went to regular style carbs many years ago. It solved MANY starting and running issues.

the bing carbs have a plastic fulcrum, ?are those carbs a problem?