371xp running lean

[willysmn]

The saw would die when given throttle. replaced pumper hose, checked gas line for breaks, disassembled carb to replace kit even though it looked OK. Fine sawdust in carb screen, couple of larger pieces in the pump side. Blew all that out with needles out. Did not remove plugs in carb body. Gasket looked good and same for the rubber intake, but did not take it off.
Wasn't much different after all this. Opened l and H about 1/3 turn and runs good and blubbers on high end while cutting. But I am suspicious it is varrying the mixture some, from rich to leaner. NOt sure though. Cut 2 28 inch pine logs while tuning it
Any ideas?.

 

[mountainlake]

Sounds like opening the low a bit made it run better, blubbering in the cut it a little rich on the high. Tune it so it runs good for now, if it starts running lean or not taking throttle then look for air leaks, bad fuel line ( just put a new one in) etc. Most likely just had some crud in the carb or you switched to crapola fuel . Steve

 

[logger 12345]

don't know how old you're saw is,but i do know that when my brand new husky 365sp starts running a little lean
i need to edge the chain,the indicator is always dusty cutting,(so in fact it don't run lean,read on)- at this stage it still cuts great so you wouldn't really spot it,this would fool you,when the edge goes dead the chain slips a little whilst cutting,so this makes the saw scream,like i say i could keep cutting with it for ages then as it would be still good.

the husky won't do this cold,ie- revving it unloaded,it will burble,it needs to be cutting a while and the temps up,then when the chain starts to slip a little & not helped by the heat,it makes the saw scream and rev higher.

i edge mine always with file,i use a 24" chain,and after every edge it's perfect again,saw won't rev anymore then
so high cause it's cutting more and the engine is always under enough load.

bear in mind after an edge i can cut tonnes and tonnes of wood for a very long time,i edge my chains very good
and never with grinder! i get long life out of my chains.

just something i have spotted with mine.

my carb is also self set from factory,the auto tune thing,which means i can't adjust it,but this only tunes to allow for atmospheric conditions and engine temps, but the chain slip thing still effects it and lets it over rev if edge is gone down.


hope this helps

dan

 

[lone wolf]

What about a vac test?

 

[willysmn]

I have not done the vac test yet. This saw has had a lot of problems. Its tank was busted and the flywheel "key" was sheared. So a used tank and flywheel were installed. And then I thought it was ok. I'm pretty sure it was last year. Now not at all ok until richened a little. The other thing I did before putting the kit in the carb was to use a new gas hose to a small bottle of fuel, and it died when given throttle just like on the main tank.

My thinking is if the engine becomes richer when the needles are opened some, the pump fuel delivery side of the carb cant be bad or the opening the needles would not make any difference.

I appreciate the suggestions

 

[lone wolf]

I have not done the vac test yet. This saw has had a lot of problems. Its tank was busted and the flywheel "key" was sheared. So a used tank and flywheel were installed. And then I thought it was ok. I'm pretty sure it was last year. Now not at all ok until richened a little. The other thing I did before putting the kit in the carb was to use a new gas hose to a small bottle of fuel, and it died when given throttle just like on the main tank.

My thinking is if the engine becomes richer when the needles are opened some, the pump fuel delivery side of the carb cant be bad or the opening the needles would not make any difference.

I appreciate the suggestions

Sounds like you should do the test !

 

[sprintmotor45]

You really need to pull the welch plugs out of the carb and clean the small fuel holes. If that doesnt work go after the fact you have an air leak.

 

[mountainlake]

Carbs do clog up , 1/3 of a turn out on the low is no big deal for sure if it adjusted a bit lean too start with or fuel got worse. I'd adjust good and do a vac test if those adjustments didn't hold, not before. Sounds like 1/3 open on the high made it run rich which points away from a vacume leak. Steve