Saw stalls if turned

[rjmorrow]

Ok, so i have an old Homelite XL-12. It cuts fine for my needs, except it has began stalling and running erratically. This is especially evident if the saw is turned on its side, it will almost certainly stall within 5-10 seconds. I have replaced the fuel line and filter. I am not sure what to look at next. The carb? (I have determined it is a Walbro Sdc-62) and if so , what am i looking for ? Any help would be great


Thanks

 

[NWCS]

i would suspect crank seals. i think i have some aftermarket ones if you need them. XL12 parts are rather common and are available many places. hard to kill an old XL12!

 

[RiverRat2]

i would suspect crank seals. i think i have some aftermarket ones if you need them. XL12 parts are rather common and are available many places. hard to kill an old XL12!

Yep,,, and check the clutch side for play.bearing wear, you should be able to apply pressure radially and it should have 0 play................ same on flywheel side but the clutch side catches most of the torsional load.........

 

[rjmorrow]

Alright, i began to tear the saw down this morning, now my question is, do i need to get the tool for clutch removal? or is there a trick to doing without? or do you just make your own ? i assume it is threaded on as it gives an arrow for removal.


Thanks

 

[ericjeeper]

just make a spanner

poke two somethings in there and put a bar between em and turn

 

[Kneejerk Bombas]

Take out the spark plug and put some rope in there to stop the crank from turning.

 

[rjmorrow]

Well after mild cursing and some blood loss, i have exposed both sides of the crank. As for play, they seem tight to me. There is a micorscopic amount of movement and thats it. I did discover some piston scoring but on a saw of this age and various owners i would think that would be expected.
So i guess i wonder, couldnt the seals be bad, but the bearings be good ? meaning crank play but still have compression loss ?

 

[NWCS]

having just the seals bad is most common. every XL12 i have ever had has had a bit of slop in the crank, seems to be just how they are. they used needle bearings instead of ball and they are not a press fit like the modern ball bearing setups.

 

[rjmorrow]

Ok, so what would be the best way to verify that the seals themselves are either bad or good? Ignoring crank play.
I appreciate all of the help here. I havent done major chainsaw repairs before,but I figure it is a good time to learn.

 

[RiverRat2]

do have a crank case pressure test kit, if not you can make one with a little ingenuity.... Do you have a compression tester with a quick connct style guage????

 

[rjmorrow]

Yes, i have a compression tester with quick connect as you describe. Are you suggesting plugging exhaust port? and then what do i do about reed valve, plug the intake as well ?

 

[RiverRat2]

yes you can do it with a strip of rubber between the carb/muff and intlke/exhst ports, just loosen the carb/muff slip the rubber ecluders in resnug carb/muff,, and a small hand pump (like a blood pressure squeeze bulb) with rubber hose slipped on to the male quick connect of your comp tester slight pressure a guaged 0-15 or 30 psi t'ed into the pump out put hose would be great stihls #s are about 8 psi and use a sprayer with soapy water to search for leaks,,,,,,

 

[Lakeside53]

Seal are a likely cause.. but check the obvious also - carb needle badly worn, other carb issues, hoses, etc...

 

[rjmorrow]

Saw fixed

Just wanted to say thanks for the help. The xl12 is back together and running great. Changed out the crank seals, gave it a thorough clening, carb rebuild kit, (I damaged a gasket). Cut for a couple hours the other day and seems to be running good.