just runs on choke

[dieseldod]

FWIW--I once had a 1963 Galaxy, that one morning would start and idle just fine, but if I tried to get it above idle it would die, instantly. Could start it with perfect reliability, and idle it all day--but try to do anything else--die. In exasperation I called a mechanic friend I knew, this in a mining town just south of the Yukon border in BC. He said 'Your coil has failed'.

'What??--it starts just fine!' He explained that the coil secondary turns are kept separated by a tar-like potting compound; when it fails and more serious than idle demands are made to the coil by increasing the frequency at which they have to supply a voltage that will jump the spark gap, the coil turns can short out either on the case or to each other; the spark-jumping voltage disappears. Went down to his shop and got a new coil--instant (and permanent) fix.

Who knows, it just could apply to chainsaw coils too. Never happened to me before or since; that was in 1971--in Cassiar, a town that no longer exists.

(BTW--if you're scared of asbestos--why am I still alive? My office (exploration geology) was right beside the drier exhaust, that was measured to blow out 6 tons of asbestos dust an hour.)

yes those old coils were fun werent they? ive had my fair share of those ,they didn,t like damp or water.

 

[stihltech]

I hear a lot of "what ifs". Not much diagnosis.
Before replacing a carburetor or ignition (unless you can prove no spark) the vacuum and pressure test are a must. The carburetor can only control what goes through it. Any leak past it will make the saw lean and cause all kinds of running issues. Idle and off idle the most common.
The other place to look in the carburetor are the idle and off idle transition holes in the carburetor bore. I run a tag wire into them to make sure they are not restricted. Cured many an 034/036/360 doing this.

 

[dieseldod]

I hear a lot of "what ifs". Not much diagnosis.
Before replacing a carburetor or ignition (unless you can prove no spark) the vacuum and pressure test are a must. The carburetor can only control what goes through it. Any leak past it will make the saw lean and cause all kinds of running issues. Idle and off idle the most common.
The other place to look in the carburetor are the idle and off idle transition holes in the carburetor bore. I run a tag wire into hem to make sure they are not restricted. Cured many an 034/036/360 doing this.

i agree

 

[Old2stroke]

If it continues to run when the carb intake is blocked, it HAS to be getting air from somewhere that it shouldn't.

 

[lwmibc]

it can be running away quite the thing and i can block the intake with my thumb and it dont bother it any. it must be getting air from somewhere to run, would the base gasket be leaking? i never sprayed around there when i did the intake and crank seals i will likely delete gasket and port it a bit while i,m at it if thats the case

Gotta be a big hole somewhere.

 

[steele_109]

Hi I have found many air leaks with a can of carb or brake clean.People will say it's dangerous but I've done it to hundreds and I'm still around.Put the straw in it and spray behind the clutch,carb, flywheel and the base gasket, when it dies you have found your leak.Oh and the carbs can have air leaks as well.But you have to pressure test them to find the leak.