husqvarna 346xp ne not running

[nhuntington11]

Hi Everyone,

three weeks ago I bought a used husky 346xp ne on craigslist. Before I bought it I ran it, cut with it, and gave it the once over. I have been cutting pulp with it for the past couple weeks and it rips through everything i throw at it, it was running great. I did hardwood firewood and it tore through that as well. I really like the saw and notice the xp after running a 353 for a time as well. I have no reason to complain about the saw. However today I was cutting and i noticed that my chain was whipping around when the throttle was off. it was going fast enough to make sawdust when i touched it to wood, but i could stop it by leaning on it a little. i thought oh, no problem, i adjusted the throttle screw and it stopped and I kept going. about an hour later the saw bogged down and died, and after that would not start except when i was holding the throttle in. I took it home and tried to retune the carb starting with the tighten all the way, then loosen 1 turn counterclockwise, with no success. it runs at idle now, sometimes, but the chain never stops moving, and i can't find a place between the L and T screws where it will remain motionless, yet not cut out. WHen I rev it it stays revved after I let go of the throttle for a few seconds, then the chain slows down slowly and comes to a stop, then the saw dies. I am at a loss. I think i hear a whistle when i pull the starter, but not when its running, and it wouldn't rev at all if their was an air leak, right? Anyone have any suggestions? I'll try anything.

Thanks, Nick

 

[old-cat]

Air leaky teaky.

 

[blsnelling]

Sounds like you developed an air leak. My guess is that you scored the piston when you continued to use it. Pull the muffler and see.

 

[sunfish]

Yep, it's an air leak and now likely a scored piston.

Very good saw and well worth fixing!

 

[nhuntington11]

ill definitely check that out once it warms up above freezing here. thanks!

 

[sunfish]

Anytime a saw starts idling too high, or not coming down to idle quickly, it probably has a air leak and should not be run until the problem is fix. Air leak = roached piston and possible cylinder damage.

 

[nhuntington11]

i just took the cylinder off the piston and took some pics that i will post. they don't look scored to me based on pictures i saw online, but i don't know honestly. when i went to take the cylinder off the 4 screws that hold it down were all loose. might that be an air leak? how can i tighten them so they won't loosen but are still removable if that is the case? thanks
nickView attachment 275115View attachment 275116View attachment 275117View attachment 275118View attachment 275119

 

[sunfish]

Looks good! Sure sounds like an air leak, but might just be carb trouble, take the carb apart, clean and check it out.

Also, if your chain was running on at low idle, it needs clutch springs and /or a sprocket bearing.

 

[71dart]

i just took the cylinder off the piston and took some pics that i will post. they don't look scored to me based on pictures i saw online, but i don't know honestly. when i went to take the cylinder off the 4 screws that hold it down were all loose. might that be an air leak? how can i tighten them so they won't loosen but are still removable if that is the case? thanks
nickView attachment 275115View attachment 275116View attachment 275117View attachment 275118View attachment 275119

Loose cylinder bolts can definitely cause an air leak. I can't say I've ever had them loosen up on me but I suppose you could use medium strength loctite on them. And while it's apart check the intake boot and impulse line for cracks. Then, if you have the tools, do a pres./vac. test just to be sure it's sealed up good.

 

[nhuntington11]

thanks everyone. ordered a carb rebuild kit and when that gets here ill put it all back together and see what happens

 

[295 tramp]

Sounds sorta like my 262xp, couldn't get the chain to stop while idling.
I thought I had carb problems. I took the clutch cover off and could move the clutch shoes without alot of force.
I put another clutch on it and could not easyly move the shoes. It tune right up.
Is you clutch a three shoe with one main spring?

 

[nmurph]

...WHen I rev it it stays revved after I let go of the throttle for a few seconds, then the chain slows down slowly and comes to a stop, then the saw dies...

If you have the needles set correctly (as stated), this statement means you have an air leak. A carb kit is barking up the wrong tree.

 

[272super]

If you have the needles set correctly (as stated), this statement means you have an air leak. A carb kit is barking up the wrong tree.

Yep. Pressure test it.

 

[redunshee]

Loose cylinder bolts can definitely cause an air leak. I can't say I've ever had them loosen up on me but I suppose you could use medium strength loctite on them. And while it's apart check the intake boot and impulse line for cracks. Then, if you have the tools, do a pres./vac. test just to be sure it's sealed up good.

Don't know about the blue loctite. Is it fuel resistant?
Bob
Sorry, you were referring to the bolts. My bad.

 

[sunfish]

Looks good! Sure sounds like an air leak, but might just be carb trouble, take the carb apart, clean and check it out.

Also, if your chain was running on at low idle, it needs clutch springs and /or a sprocket bearing.

I should have added, if the cylinder bolts were very lose, that very well could be your air leak. I've never needed loc-tite to keep em tight, just torque em good and go.

 

[nhuntington11]

@295 tramp - im not sure what you are asking. the clutch has two clutch springs, which i ordered in response to sunfish. hopefully that helps.

@ 272super - even if i didn't need the carb kit its all apart now, and ive heard that they burn up quickly now with the ethanol in gas. thought i might as well replace it for 12$. i also got a new spark and air filter. why not.

@everyone else - when i put it back together im going to tighten the cylinder bolts good and tight! no loctite at this point, it sounds like no one else needs it, so if i do i'll probably get new bolts. hopefully that fixes the air leak

can anyone explain the theory behind the air leak causing the high, prolonged revs? ive been trying to think my way through it but its not making sense upstairs, if you know what i mean. i realize that the air is pulled into the system, is it before combustion? or after? and that leans out the fuel mixture, obviously only if the leak is in the system before combustion. basically i don't understand why this would happen!

 

[mdavlee]

When I put huskies back together I lock tite almost all the bolts on them. Don't use the red or anything high strength. Just some of the blue and it will let you take the bolts back out easily but you won't have to worry about them coming loose.

The air leak is getting extra air into the cylinder and will keep the revs up leaning the mixture out. That's how it will score up a cylinder if you don't catch it in time.

 

[excess650]

I've had air leaks on a couple of saws, but caught it quickly and had no scoring. My 272xp somehow tore the gasket between the intake and cylinder. I've replaced that gasket and it now runs fine. My early 357xp still had the OEM plastic intake clamp, and I haven't gotten a 372/390 screw clamp to replace it yet, but that should take care of its problem.

High idle problems, idle changing as you move the saw from upright to L/R sides, usually indicates a leak. It can be a gasket, or might be crank seals, impulse line, fuel line, etc. Your loose cylinder bolts could well have been the culprit, but you won't know for sure without a vac test. You were lucky to catch it before scoring.