335XPT Help

[Hard Knocks]

I have put enough labor into a 2001 335XPT to by a new saw. I can not remember ever fighting this long and hard to solve a saw problem.

Saw starts cold 3 or four pulls runs fine with good throttle response. Warm it up for minute or so and let it idle. Now the fun starts either idles fine, surges up and down like it has an air leak or just stalls like it has been shut off. Try to adjust the carburetor low speed first 13,400 rpm high speed 2800rpm idle. If you watch the idle with the tach 2200rpm-3400rpm chain turning.

I have pressure and vacuum tested the crankcase. This saw has zero leakage. I have tired spraying carburetor cleaner around the seals, crank halves and intake manifold while saw is running. No change. I have replaced the intake manifold, impulse line, fuel line, and fuel tank vent even though all parts tested or appeared to be fine.

I have ultrasonically cleaned the carburetor while fully disassembled (even removed the semi fixed jet/diffuser) rebuilt with full kit and pressure tested. Taken the carburetor apart more times than I will mention. Replaced fuel filter. Out of desperation tried a brand new carburetor - no change.

Replaced the spark plug tested ignition system, ran with shorting wire disconnected. Out of desperation tired brand new ignition module. - no change.

Compression reading on hot saw 185 PSI, Piston an cylinder look very good through exhaust port. Piston still has machining marks.

This saw has got an incredible amount of power when cutting.

I also noticed that the top speed rpm is not consistent from one run to another. It seems that you have got to continually compensate the carburetor for whatever the problem is.

I know that the 335's were full of running bugs, but I have never had one that I could not fix. I hope that I am overlooking something simple. The only thing that I have not done is pull the piston, but I really don't think that I will find anything wrong.

Any help is much appreciated.

Doug

 

[Grande Dog]

I had one that sounds like Deja Vu to the one your dealing with. It's been long enough ago that I can't say exactly remember whether it was the crankcase or the cylinder. In my head I'm leaning towards the crankcase. It was mis-manufactured and when it reached operating temperature it would warp and leak. The only way I found this out was to take another good running saw and switched the engine component only and it did the same thing. The reason the vacuum/pressure test wouldn't show it is because it takes so long to put the test equipment on, it would be cool again. So I took it apart and resealed the crankcase/cylinder mating surface. I sent it out with the customer and it came back after few hours (of commercial) use with the same problem. I never did find the exact spot it was leaking. Wherever it was the sealant couldn't keep it closed up. So I believe it was the the crankcase change that cured it. Went out and I never saw it back. The guy is a local so I'm sure it stayed cured or I would have definitely heard back about it. If you don't have parts to throw at it, my only thought would be to get the engine component where you can pressure check it and then put something like a heat gun or heat lamp on it to see if you can get it to leak.

 

[Hard Knocks]

Thanks Grande Dog for sharing your experience. The saw is now on a couriers truck on it's way to Husqvarna technical department. What you have told me makes perfect sense. This saw belongs to a commercial customer and I could not bare to hold them up any longer. I am very embarrassed about this whole situation. If I had another 335 kicking around the shop I would have tried switching out the crankcase. I will post the findings from Husqvarna.

 

[l2edneck]

Those saws kicked some serious butt,those bugs are why mine is broke down on the shelf.Had basically same prob with the 2 when they were six months old.Guy i was workin for just sidelined em then sold me one for cheap.I suffered with it thru side jobs.I dont think ill ever get rid of it.Gonna stick it on my go-ped 1 day.

 

[PainAndMurphy]

I know it's an old thread.. but.. oh well..

Links to demonstrate what trouble I am facing/having now with one 335 XPT I got from a friend:

Chainsawr husqvarna 335 xpt chainsaw intake boot

Husqvarna 335 338 xp repair


How the HECK am I gonna get one soon ??

 

[PainAndMurphy]

?

Links to demonstrate what trouble I am facing/having now with one 335 XPT I got from a friend:

Chainsawr husqvarna 335 xpt chainsaw intake boot

Husqvarna 335 338 xp repair


How the HECK am I gonna get one soon ??

Get one of what?
Saw or the part (intake boot) ?

Thx

Jo.

 

[PainAndMurphy]

Anyways, here's a fix I did to a friend's 335 XPT..

I also have a video, but I didn't know AS wouldn't accept .3gp files..... so, it's what I have to share now..

oh - and if any of you wants the address for this part, I will add it by request.. I'm not here to sell anything, it's just the best place I have found since the in 2nd 'best' place it costs 150% of where I got it from - before shipping (!) .. and eventually I paid less than the latter in total including shipping overseas from Canada.. just saying.

 

[HittinSteel]

I plumbed a fuel tank cap vent from an ms200 (or maybe it was a poulan) in to the husky gas cap. It's still a little finicky but is a little hot rod with a muffler mod.

I remember reading that the tank vent location is the real problem on these saws........ adding the vent to the gas cap was a solution posted by a member that has worked well enough for me.

 

[PainAndMurphy]

matter of fact..

I plumbed a fuel tank cap vent from an ms200 (or maybe it was a poulan) in to the husky gas cap. It's still a little finicky but is a little hot rod with a muffler mod.

I remember reading that the tank vent location is the real problem on these saws........ adding the vent to the gas cap was a solution posted by a member that has worked well enough for me.

matter of fact the vent mod wasn't mine this time..

A bit 'off topic' model wise, I did another breather mod on ECHO's like CS-341, CS-300 etc'..
As soon as I had a reason to take the flywheel off or do a major clean - I'd take the fuel tank breather out from the somewhat ridiculous location, sealed the passage on the wall that's between the fan compartment and the carburettor's - shorten the hose and put the vent valve right there. So whenever I suspect a tank-vent trouble - all I need to do is open the air filter and check the vent valve. So much easier I get a silly smile on my face whenever I clean the filter and see this mod.. LOL Oh - and NO troubles with tank pressure ever since.

I can take photos of whatever..


Except the 335 XPT which has been returned to the respectable owner