HELP! Husqvarna 242xp idle problem

[300whisper]

Asking for help because my desperation is getting biblical levels. I’m struggling with my neighbors Husky 242xp, which he got for free after some tree felling project and gave it to me to make it run again.
Saw was missing cylinder cover and everything between intake and trigger mechanism. Parts were relatively easy to find because this saw is/ was widely used in my neck of the woods.
Carburetor was completely disassembled and cleaned in ultrasonic, not once but twice, assembly with new carb kit. First assembly was with some aftermarket kit and I didn’t get saw running well. Luckily I found new kits from local saw shop and bought plenty for rainy day.
Cylinder was in relatively good shape. Piston had slight scoring marks, nothing catastrophic. Piston ring was way past its expiration date, so I got new Caber ring.
Measured squish w/o gasket, .013”, too tight for my taste, so I decided to make new gasket because neighbor wants reliable and easy to start saw.
After through inspection of crank seals (looked ok), bearings and cylinder I made pressure and vacuum test, passed flying colors. So far so good.
First start was around the corner after replacing new fuel filter and everything was good to go.
Saw was idling nicely with basic settings (L 1 1/2, H 1 1/4), after some small adjustments idle was 2650 rpm and WOT 13500 rpm. Cut few cookies and returned saw to my neighbor who was more than satisfied despite this project took more than 4 weeks to get parts.

Fast forward to last Sunday. Neighbor called and told me saw isn’t idling correctly and starts to rev up when saw is tilted to felling position. Ok, I’ll take a look and see what is the problem.
Couple of days ago I changed new crank seals and found out flywheel side was ”dry” and had some carbon deposits around the seal pocket. i thought this might be the problem despite the fact saw passed pressure and vacuum test. Maybe new gas and running made this seal to give up.
This morning I finally had some time to look it again. Got the saw running but same damn issue, tilting to sideways gets rpm up around 5- 600 rpm and chain starts to move. Back upright position makes it run normal idle speed. WTF?

Please note, I’m not small engine mechanic but I understand 2 stroke engine working principals. I have built almost all my chainsaws and have never experienced anything like this.
Saw is on my bench carb open, gaskets inspected, everything looks ok but I can’t get this damn saw running right.

Is this carb issue or what?

Thank you in advance.

 

[farminkarman]

Asking for help because my desperation is getting biblical levels. I’m struggling with my neighbors Husky 242xp, which he got for free after some tree felling project and gave it to me to make it run again.
Saw was missing cylinder cover and everything between intake and trigger mechanism. Parts were relatively easy to find because this saw is/ was widely used in my neck of the woods.
Carburetor was completely disassembled and cleaned in ultrasonic, not once but twice, assembly with new carb kit. First assembly was with some aftermarket kit and I didn’t get saw running well. Luckily I found new kits from local saw shop and bought plenty for rainy day.
Cylinder was in relatively good shape. Piston had slight scoring marks, nothing catastrophic. Piston ring was way past its expiration date, so I got new Caber ring.
Measured squish w/o gasket, .013”, too tight for my taste, so I decided to make new gasket because neighbor wants reliable and easy to start saw.
After through inspection of crank seals (looked ok), bearings and cylinder I made pressure and vacuum test, passed flying colors. So far so good.
First start was around the corner after replacing new fuel filter

What help are you looking for? It wasn’t clear after reading your post.

 

[300whisper]

What help are you looking for? It wasn’t clear after reading your post.

Looks like I had hair trigger moment and hit enter too early.

 

[trooney]

I mean, it seems like an air leak. What seals did you replace? Impulse line? Leaking under base gasket when cylinder gets hot? Screws in cylinder tightened down correctly?
Had the same thing happen to me on an 024. Passed p&v test every time. Couldnt understand. Talking with a few people its possible that when thr crank rotates it hits one spot where it doesnt seal correctly. Might not be your case, but check everywhere there could POSSIBLY be an air leak. Have you tested it when it gets hot? PIA but maybe only way to find the leak?

 

[300whisper]

I mean, it seems like an air leak. What seals did you replace? Impulse line? Leaking under base gasket when cylinder gets hot? Screws in cylinder tightened down correctly?
Had the same thing happen to me on an 024. Passed p&v test every time. Couldnt understand. Talking with a few people its possible that when thr crank rotates it hits one spot where it doesnt seal correctly. Might not be your case, but check everywhere there could POSSIBLY be an air leak. Have you tested it when it gets hot? PIA but maybe only way to find the leak?

I replaced crankseals, OEM. No chinesium on critical places, if I just can avoid it. Before pressing new seals in place I cleaned and checked crank and bearing seal surfaces, no visual signs of scratches or anything alarming. Only thing was small carbon deposits on flywheel side seal pocket which managed to get off with small screwdriver and shop vac. And no, I didn’t have to use excessive violence to do that.

Impulse line is integral with throat and it was clean, no obstructions, just cheked that before throwing carb to ultrasonic once more. Gaskets are ok, even pressure signs everywhere. First thing I checked cylinder bolts before removing carb, bolts were tight.
Only thing I found was uneven wear on needle valve, that is original but luckily I have new left over from Walbro rebuild kit.

If that does not help I have to test P/V test when engine is hot. I will keep you updated on that.

One more thing. Is it possible that tank vent might be compromised and cause this?

 

[trooney]

Anythings possible but reading your post it only happens when you turn it on its side?

 

[300whisper]

Anythings possible but reading your post it only happens when you turn it on its side?

That is correct. It is doing it only when tilted 90 degrees to right.

First time I got that thing running I cut only few cookies to get it warmed up and tuned (rookie mistake). I didn’t run the saw in different positions and was happy with it. Well, my neighbor wasn’t…

This is driving me nuts.

 

[quattro.pilot]

It seems like it's leaning out when tilted over on that side. There's a air leak somewhere, it will just be very difficult to find. Probably the flywheel-side crank seal. If you install another one I would use Threebond/Yamabond/Motoseal on the flange in order to seal any out-of-roundness. I would also take apart the intake and carefully use some sealant on all the flange surfaces downstream of the carb. Maybe when the saw is being tipped there's extra weight pulling the intake plumbing down and opening up a small crack? Do you know the expression "Grasping at straws"? ...because that's what I'm doing for you now....trying to think way outside the box. I have never been that confident with the 242 intake parts, too much plastic and not enough gaskets and too much of a chain of pieces. Good luck, I am glad I do not have this problem

 

[300whisper]

It seems like it's leaning out when tilted over on that side. There's a air leak somewhere, it will just be very difficult to find. Probably the flywheel-side crank seal. If you install another one I would use Threebond/Yamabond/Motoseal on the flange in order to seal any out-of-roundness. I would also take apart the intake and carefully use some sealant on all the flange surfaces downstream of the carb. Maybe when the saw is being tipped there's extra weight pulling the intake plumbing down and opening up a small crack? Do you know the expression "Grasping at straws"? ...because that's what I'm doing for you now....trying to think way outside the box. I have never been that confident with the 242 intake parts, too much plastic and not enough gaskets and too much of a chain of pieces. Good luck, I am glad I do not have this problem

Thanks for the tips. Your sigline is telling…

 

[trooney]

The problem with my 024 was the flywheel side seal. Even OEM can every once in a while throw in a defective part. Seals are cheap, at least they used to be. Not saying this is the case here, but every saw thst I've had that had a leak when tilted on its side has either been a seal or the fuel line.

 

[Stump Shot]

It is possible the seal threw its spring or bad bearing not allowing it to seal properly.
It is also possible to have a cracked fuel line and when it swings in the tank it opens up the crack.
I would recommend a pressure test of entire fuel system to .5 bar(7psi) as well as vacuum test crankcase while rolling the saw over and even put it on its side if need be.
Keep checking, you will eventually get led to the problem.
Good luck to you.

 

[CJ Brown]

Along with what has already been mentioned above, check the fuel line routing and av buffers. The fuel line has a rather tight routing on those saws and loose or worn av mounts could allow the line to be pinched when the saw is rotated. Also a vacuum/pressure test of the crankcase with the saw on its side would be my starting point.

 

[backhoelover]

What compression?
Have you pressure test the carb and fuel supply line?
Have you check the nozzle check valve in the carb?

 

[300whisper]

I don’t have numbers in front of me right now, quite busy at the moment but I get back into this at weekend. Thank you everyone for the tips.