Craftsman 3.7 Help

[jtc16]

My craftsman 3.7 (poulan 3800) will start and idle fine but has no power to rev. Very weird because I just bucked and noodled a 25' long, 24" diameter oak log with it a couple weeks ago, cleaned it with air and put it on the shelf. Got it out yesterday and it won't rev. The only time it started to rev is when the H screw was almost all the way in. Just wondering if the issue sounds familiar to anyone and could suggest something

 

[MS460WOODCHUCK]

Sounds to me like possibly packed the carb diaphragm with dust through the little hole in the cover of the diaphragm. Had this happen to me before when blowing air around the carb.

 

[jtc16]

Ok thanks will try cleaning the carb best I can, not sure what the diaphragm is

 

[ANewSawyer]

Probably part #38, metering diaphram.

 

[jtc16]

Got it fixed. Cleaned the carb out and bent the metering lever up a little. There was some dust in the carb screens and the lever was below flush with the top. Revs fine now. thanks.

 

[Wood Doctor]

Got it fixed. Cleaned the carb out and bent the metering lever up a little. There was some dust in the carb screens and the lever was below flush with the top. Revs fine now. thanks.

Looks like that carb could have been fixed with an overnight soaking in a mixed fuel bath. And, the carb screen alone could have caused that. Regardless, I'm gad to see that you saved it. These saws have a lot of grunt when they run well. Two thumbs up!

 

[jtc16]

I sprayed out the screens and took the screws out and sprayed, any advantage to soaking instead of this? It is a good saw glad it was an easy fix.

 

[Wood Doctor]

I sprayed out the screens and took the screws out and sprayed, any advantage to soaking instead of this? It is a good saw glad it was an easy fix.

Not really. It just takes longer with less human intervention. Soaking will usually not clean the strainer and that can cause bundles of fuel flow problems, air/fuel mixture problems and so on. It's amazing at how many carbs suffer from clogged strainers and much of this occurs with the older saws that have been around for so long. Many times the top end of the saw outlasts the carb.

 

[Efisher26]

New fuel filters and truefuel style gas can keep a carb clean with no effort


-Efisher26-

 

[jtc16]

I think my problem came from dust getting in around the air filter, not a very good filter on that saw.