Help with adjustments for a Poulan XXV CVA

[xraydaniel]

I have an old Poulan that I have replaced everything but the piston and crank case. This is from about the very early 1980's. After getting it started I began to make adjustments and am very bad at that. It has an idle screw, a red (high), and blue(low) that I've tried to bring 1 and 1/4 counterclockwise turns from tight. It'll start and run but the idle is messed up as the blade turns really fast when not on the trigger. If I bring the idle screw almost to zero pressure it'll stall but still will run the blade fast right before it stalls. Any thoughts? I know Poulans today are quite trashy but this one is pretty solid, not pro, but solid. I'm hoping it has no vacuum leak. Another strange nuance is the gas cap which has a pinhole in the middle seemingly there to introduce air? When I pull the cord I get a drip of gas out of that hole which to me is very wrong.

I replaced all the seals, all filters, not the gas cap of course considering the spitting issue. I know that when my father used it about 30 years ago it had some problems. I don't know the extent of it. I spent about 50 bucks on everything thus far. I love the feel of the saw and don't mind dropping some more money into it but unless I do a compression test I can't tell if there is a leak or not. Got a good source for the gas cap assembly? I can get one for 2.16 but 12.00 shipping, boooo!

 

[Dadatwins]

Carb setting on those should be around 1.5-2 turns on hi and low. The fuel top should have vent built into it and not pour fuel out, bad/no vent will not allow the saw to run properly. Another problem with them was trash getting between the reed under the carb. If you pull the carb you will see a metal flap that sometimes ended up with trash holding it open. Hope this helps.

 

[ray benson]

Initial carb setting is 1 turn open from lightly seated on the low and high mixture screws. Adjust idle speed screw so engine idles just below clutch engagement. Adjust low mixture screw so engine will accelerate without hesitation. High speed mixture screw should be adjusted to obtain optimum performance with engine under cutting load. Plug is a Champion CJ8 gapped to .025". Got this info from an Intertec Chain Saw service manual.

 

[xraydaniel]

First off, thank you dadatwins and ray for the response. One question I still have is what controls the blade's movement while in idle, the low speed screw?

 

[safeT1st]

Centrifigal Clutch

Engine Rpm triggers centrifigal clutch to engage . If idle is set to fast the weights overcome spring tension and drive is transmitted from crankshaft to sprocket drum and chain . I suppose it would be possible to have weak or broken clutch springs but I doubt that is your problem .

By coincidence I am restoring a Poulan XXV DA . There is a thread entitled " 2 Cycle Engine Assembly 101 " . It relates directly to your saw and assembly begins today .

 

[xraydaniel]

Oh lucky day! Thanks