Husky 350 Rebuild Question

[Mattyo]

Just tested a stock 44mm 350...was nearer to 170. Compression near 100 is nearly not running. Gonna have a hard time convincing me that 100 comp is normal

 

[dsell]

The 350 with dished pistons show some very low results. Seems like I seen some running in the 110 range, but that was with my old gauge.

 

[Yoopermike]

Just tested a stock 44mm 350...was nearer to 170. Compression near 100 is nearly not running. Gonna have a hard time convincing me that 100 comp is normal

http://www.arboristsite.com/community/threads/compression-for-the-husqvarna-350-domed-piston.207741/

 

[Yoopermike]

My 350 runs 110psi and I cut with it regularly.

 

[dsell]

http://www.arboristsite.com/community/threads/compression-for-the-husqvarna-350-domed-piston.207741/

Hey, I remember that.

 

[Mattyo]

I can understand a runner at 120, and I know about the dished piston on the 45mm 350's ... but 100 being normal, I dunno

 

[TNmatt]

This saw did have the dished 45mm piston and according to the shop it was around 100 but ran pretty poorly and the piston was scored

 

[Mattyo]

ya, that's because of that stupid plastic clamp

whats more interesting, I've called around to local husky dealers, and there are quite a few here in CT... they all looked at my crosseyed when I asked if they had the metal clamp in stock. one dealer said he's sold ONE, ever... this is insane because these saws are so popular....and they all eventually eat themselves because of the air leak.

oh well.. ..but it certainly explains lower compression...given a little more running that saw would be down to 70 psi when the ring sticks

 

[TNmatt]

Well got the saw all put back together and started it up and I can't say that it runs any better than it did before. Pretty frustrated. I noticed 2 bad spots on the cylinder that I hadn't noticed before, they were barely deep enough to catch my fingernail on. Not sure if you can tell in the picture but I'm assuming that is the problem. So now i guess I'm looking for a new cylinder but I haven't seen just a cylinder, everything Ive found online comes with a piston which I already have. Is it worth trying to hone this one?

 

[dsell]

I don't think that would hurt. Meteor piston with Mahle cylinder? Probably better check the squish. What is your compression? Did you leak test the saw? Can you tell us some more about how it runs?

 

[TNmatt]

I didn't leak test it because I didn't have the equipment but I resealed everything. My grandad is bringing me a compression gauge tomorrow so I'll check that and let you know. I don't have a micrometer either so I didn't check squish. It started right up but it idles pretty high, I started with all the carb screws backed out 1 turn to start and the idle would speed up a little but would never slow down enough for the chain to stop spinning. I may have to break down and buy a pressure/vacuum tester this week.

 

[Mattyo]

you can always test it with some carb cleaner.... you have to be careful you don't start a fire, but get the saw running and spray carb cleaner at the intake.... if the saw bogs and dies you have a leak

if the seals and bearings are new then I can't imagine that's the leak... what did you seal with?

 

[TNmatt]

I didn't put new bearings or seals in it I just re-sealed the riser to the case. I pretty much followed your video step by step as far as sealing goes Mattyo. I used the gas resistant Permatex Motoseal. I also put the metal clamp on the intake as well. Do the decomp valves on these saws leak ever? If I end up having to tear it down again I'll do the bearings and seals, I guess I naively thought they would be fine.

 

[TNmatt]

I just sprayed carb cleaner around the intake while it was running and it didn't seem to do anything

 

[dsell]

Yes, the decomps certainly leak. Have you adjusted the carb?

 

[TNmatt]

I tried adjusting the idle screw and low speed screw but it would only increase the idle it wouldn't slow down any, I didn't mess with the high speed screw yet.

 

[dsell]

Sorry for the questions, but I don't know your experience. Are the limiter caps off?

 

[TNmatt]

No problem, this is the first time building a saw and I'm no mechanic so any advice is helpful. I'm not sure how to check for the limiter caps, any advice?

 

[Mattyo]

I love to save parts if I can, but if I saw a chassis melt like yours did, those bearings and seals go in the trash. it is not possible to pull them apart, so they go as a unit. new bearings and seals go on easy, so that's what I would do, also, I think cleaning the cylinder is fine at this point, and swapping out the decomp valve is a good idea too.

if it doesn't idle, something is up.... too much air at idle will keep the rpm high. ie, air leak.

if the saw is still together, you can pull the clutch off and check the clutch side seal when the saw is running for a leak, again, carb cleaner...

your intake probably ISN"T the cause of the leak if the carb cleaner does nothing... on my 385xp my intake clamp was loose, and when I sprayed carb cleaner, the saw died. tighten the clamp, all better

 

[dsell]

No problem, this is the first time building a saw and I'm no mechanic so any advice is helpful. I'm not sure how to check for the limiter caps, any advice?

They may look something like this and you will only be able to turn the screw so far if they are on. You would pry, pull, cut them off carefully, or grind the part that's keeping them from turning. You should be able to shut the saw off with these screws. If you can't, something is wrong with the carb. Are you sure the butterfly is closed? Make sure the throttle linkage isn't binding on something. These carbs have a fast idle catch, and you won't be able to adjust the low side of the carb if the butterfly is partially open.