Saw cuts out under load

[HittinSteel]

At my whits end here and looking for some suggestions

Nice 346XP I picked up used. Has 165 lbs. of compression.
Saw cuts like a banshee for a cut or 2 and then looses power. If I take the saw out of the cut, it will reach max revs again. Put it back in the wood and it bogs down.

I have replaced the carb with a good working one
Replaced the tank vent
Replaced fuel line and filter
Cleaned exhaust port and opened the muffler
It has a good working unlimited coil

What have I missed?

 

[smokinj]

Check lines again....Sounds like one maybe pinched.

 

[HittinSteel]

Will do. I think I need to have a look at the impulse line as well.......never checked it.

Although I do have a trade lined up for a 335xp (like the 200T) if I can't get it working right.

 

[smokinj]

Will do. I think I need to have a look at the impulse line as well.......never checked it.

Although I do have a trade lined up for a 335xp (like the 200T) if I can't get it working right.

Really sounds like a line issue. I have done this one before and when going back scratching your head at about half speed BAM there it is!

 

[raybonz]

I am no expert but to me it sounds like you're running lean.. Maybe you have loose carb bolts or a leaky/cracked gasket at the carb.. Look at these things if the other ideas don't pan out..

Ray

 

[DexterDay]

Will do. I think I need to have a look at the impulse line as well.......never checked it.

Although I do have a trade lined up for a 335xp (like the 200T) if I can't get it working right.

Is it a 335XP or a 339XP??

Also how "New" is it?

My 435T is not a Pro saw But you would be surprised. Also a 435 (Standard) that I am about to sell/trade.

Both are about 4 months old and been used 3 times. For almost an hour of use Max. Still have lots of Paint on the Bar. Just looking to trade/sell to get some bigger saws

New cost is only $299.99 for the Top Handle. $269.00 for the Standard 435.

Would have PM'd but cant post Pics in a PM and would rather you see.

Cant comment on the 346XP. And if this does not look or sound appealing (Have talked in PM's with you. I know your a "Pro" Saw guy). Then disregard.

Sorry for the hi-jacking...

 

[MasterMech]

HittinSteel,

+ 1 on fuel/impulse lines.

Couldn't hurt to throw a known good spark plug in it. I've seen wacky plugs do even wackier things. Since you said it runs like the devil for a cut or two, I think the air filter is prolly fine but can't hurt to make sure it's clean.

 

[HittinSteel]

Walking Mayhem through a press/vac test in his thread reminded me, the 346 does not have a dedicated impulse "line" like stihl saws......no wonder I haven't checked it lol.

I'll try a different plug, but I think I already did that. Filter is good and clean.

Dex....I'd keep that top handle if I was you. Nice for the small stuff.

 

[HittinSteel]

I am no expert but to me it sounds like you're running lean.. Maybe you have loose carb bolts or a leaky/cracked gasket at the carb.. Look at these things if the other ideas don't pan out..

Ray

Interesting thought. Another symptom is I don't think adjusting the carb needles changes the saws attitude like it should......

 

[smokinj]

I am no expert but to me it sounds like you're running lean.. Maybe you have loose carb bolts or a leaky/cracked gasket at the carb.. Look at these things if the other ideas don't pan out..

Ray

Interesting thought. Another symptom is I don't think adjusting the carb needles changes the saws attitude like it should......

Thats not good sure crank seals are good?

 

[MasterMech]

I'd go ahead and vac/pressure test to confirm crank seals, base gasket, etc are good and then do a cyl. Leak-down test. 346XP's have been known to wear out the top-ends quicker than most due to the extremely high rpm's they run. (15K+, no-load, if I remember right.)

 

[HittinSteel]

It has a newer top end and pulls 160 lbs of compression. I'm just gonna trade the thing off, as I could use a top handle for brush duty and I like my muffler modded 260 (set for a woods port this winter) and my 55 for the small wood tasks.

 

[smokinj]

It has a newer top end and pulls 160 lbs of compression. I'm just gonna trade the thing off, as I could use a top handle for brush duty and I like my muffler modded 260 (set for a woods port this winter) and my 55 for the small wood tasks.

Anytime I get nothing out on the H and L screws I assume it crank seals. >:-(