# Craftsman Chainsaw will start, won't run



## biffula (Nov 10, 2011)

It's a 42cc. It will start when very cold and run for 20-30 seconds. I've checked the muffler. I've checked spark. I've cleaned the carb(everything looked very clean, including the screen). I tightened the adjustment screws all in, then backed out 1-1/2 turns. If I try to give gas, it dies. The piston and cylinder looked good from what I could see when I had the muffler off. I'm at a loss. The carb was rebuilt last year and ran like a charm. The last time I used it I ran it dry for storage. It's new gas this time. What could the problem be?


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## justin3 (Apr 10, 2007)

Have you checked the fuel pickup and fuel line for any breaks?


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## usmcgrunt (Sep 16, 2007)

Hello and Welcome.Personally,I store all my equipment with stabilized gas in it.
The diaphragms may be dried out and not pliable enough to function as they should.As Justin said,check your fuel lines for cracks and make sure the fuel filter is still attached inside the gas tank.It may need another carb rebuilding kit to operate again.


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## geogrubb (Jul 28, 2006)

Try opening the "L" screw by about 1/8-1/4 turn to see if the throttle up will improve. Have a good one. Geo


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## bob1190 (Apr 18, 2010)

Have you checked vacuum and pressure?


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## biffula (Nov 10, 2011)

"Have you checked vacuum and pressure?" _ Not yet_

"Try opening the "L" screw by about 1/8-1/4 turn to see if the throttle up will improve. Have a good one. Geo" _ I have tried adjusting the L, so far with no luck._

"Hello and Welcome.Personally,I store all my equipment with stabilized gas in it.
The diaphragms may be dried out and not pliable enough to function as they should.As Justin said,check your fuel lines for cracks and make sure the fuel filter is still attached inside the gas tank.It may need another carb rebuilding kit to operate again." _Fuel lines and filter are good. I forgot to post that. I was wondering if the diaphragms may already be dried out and be the problem. I'd always been told to store dry. May have to start storing with fuel. I always stabilize fuel anyway._

"Have you checked the fuel pickup and fuel line for any breaks?" _Yup. Fuel lines and filter are good. I just forgot to mention that in the original post. _


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## usmcgrunt (Sep 16, 2007)

As Bob1190 suggested,check the compression and post your results.I don't know if this saw has the cylinder as a separate piece on the crankcase or all one piece.If the cylinder is bolted to the case,make sure the mounting bolts are tight.All 2-cycle engines need a minimum of 100 psi compression to run properly.If compression checks good,I would pull the carb apart and check the diaphragms for stiffness and replace if not pliable.


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## biffula (Nov 10, 2011)

usmcgrunt said:


> As Bob1190 suggested,check the compression and post your results.I don't know if this saw has the cylinder as a separate piece on the crankcase or all one piece.If the cylinder is bolted to the case,make sure the mounting bolts are tight.All 2-cycle engines need a minimum of 100 psi compression to run properly.If compression checks good,I would pull the carb apart and check the diaphragms for stiffness and replace if not pliable.


Here's the latest: Put a new carb kit in today. It will only run wot. As soon as I let off it dies. I've tried adjusting low idle to no avail. I guess a compression check is next.


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## justin3 (Apr 10, 2007)

Well a compression test is a good idea, but you may still have a restriction in the low speed jet on the carburetor. Have you removed the low speed screw and blown through the hole with carb cleaner and compressed air?


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## biffula (Nov 10, 2011)

justin3 said:


> Well a compression test is a good idea, but you may still have a restriction in the low speed jet on the carburetor. Have you removed the low speed screw and blown through the hole with carb cleaner and compressed air?


Did with cleaner, not with air. I'm gonna take it apart again and do that.


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