husqvarna 455 rancher low on power?

[sven556]

Okay, I got this saw cheap and I am working on getting it going again. It had no compression when I got it; which turned out to be a stuck ring. I tore it down and cleaned up the ring groove and installed a new caber ring. While I had it apart I replaced both seals and tested pressure and vacuum. I also cleaned the carb and replaced the diaphrams and gaskets, replaced all fuel lines, purge bulb, and filter.

It just seems like the saw has no power. It seems to react normally to adjusting the carb screws, and will idle and rev up like normal but I can out cut it with an ms200t and there is no chance I can bury the 18" bar even with a light touch. The bar and chain are brand new, only used for the 1/2 tank I've run so far.

Things I have checked so far: compression with the new ring is 144 psi (only 1/2 tank on it), chain break isn't binding on the drum, spark plug looks like a nice brown color, muffler and screen are not plugged up, air filter is clean.

What am I missing? Any ideas what to check?

 

[thompsoncustom]

how do the rpms sound out of the cut and in?

A video would probably help.

 

[mountainlake]

Try opening up the high 1/2 turn, if too lean it will be doggy. Also check the muff for being clogged up, Muff screen. Steve

 

[Wood Doctor]

Try opening up the high 1/2 turn, if too lean it will be doggy. Also check the muff for being clogged up, Muff screen. Steve

I agree, and it sounds like it's running lean and fuel starved. If this fails, he should just plain replace the carb.

 

[AmishKyle]

I had one same issues picked up one straight gassed. Did full rebuild and always felt lean. Finally bought a new carb and it runs like ifs EFI

 

[sven556]

Looks like the consensus is that it's running lean. The high needle is 2 1/2 turns out. To my ear it 4-strokes at wide open-no load. When I turn it another 1/2 turn out it slows down a lot and sounds really rich to me, but maybe that's where it needs to be. Anyone know what the initial set point is for the hi and lo needles?

Thanks for the advice. I'll work on adjusting it. I also ordered an aftermarket carb to try.

 

[rupedoggy]

Comparing your 455 to a 200t, well the one is a professional hot rod saw and the other is a homeowner type wood cutter.

 

[Bob_w]

Okay, I got this saw cheap and I am working on getting it going again. It had no compression when I got it; which turned out to be a stuck ring. I tore it down and cleaned up the ring groove and installed a new caber ring. While I had it apart I replaced both seals and tested pressure and vacuum. I also cleaned the carb and replaced the diaphrams and gaskets, replaced all fuel lines, purge bulb, and filter.

It just seems like the saw has no power. It seems to react normally to adjusting the carb screws, and will idle and rev up like normal but I can out cut it with an ms200t and there is no chance I can bury the 18" bar even with a light touch. The bar and chain are brand new, only used for the 1/2 tank I've run so far.

Things I have checked so far: compression with the new ring is 144 psi (only 1/2 tank on it), chain break isn't binding on the drum, spark plug looks like a nice brown color, muffler and screen are not plugged up, air filter is clean.

What am I missing? Any ideas what to check?

Muffler spark suppressor screen blocked?

I would check raker teeth next, probably .025 down is right. I use straightedge tooth to tooth, .025 feeler gauge just touches. otherwise file. Nice to put a sloped leading edge.

Next Ignition module gap, probably .012 3 sheets of paper, or business card between the module and the magnets. Loosen the module, let the magnets pull, tighten module.

The flywheel timing. Pop the flywheel, Check its location to key, Torque to spec.
I mark the key location on the top of the crankshaft and the flywheel, with a marker, since you can't see it later, if it slips during torqueing.

 

[Pioneer]

Give it more time to break in. How was the cylinder wall prepped? If it wasn't given a light scuff you may need quite a bit of time before the ring mates properly.
A friend has a 455, it's no dog and only a bit slower than his Echo 590 with the same type chain.

 

[farmguywithasaw]

Those caber rings are fairly good quality and made fairly hard. Probably 10 tanks or so before it’s broke in. Also make sure the rest of the saw is in good working order, check the condition of the clutch and that the oiler is working good and lots of oil to the chain. A dry chain will act like no power. Make sure it the correct pitch as that can bugger you up too.

 

[singinwoodwackr]

Looks like the consensus is that it's running lean. The high needle is 2 1/2 turns out. To my ear it 4-strokes at wide open-no load. When I turn it another 1/2 turn out it slows down a lot and sounds really rich to me, but maybe that's where it needs to be. Anyone know what the initial set point is for the hi and lo needles?

Thanks for the advice. I'll work on adjusting it. I also ordered an aftermarket carb to try.

Try 2 turns each and go from there.
this assumes you have pulled the limiters. That saw isn’t like early Huskys at 1 each.