I have a Husqvarna 455 Surging/ Wavering at full throttle

[Jeffbecky1]

I have a Husqvarna 455 Surging/ Wavering at full throttle I changed hoses and filt cleaned carb. What is the problem?

 

[NPKenny]

Serious questions to help diagnose your symptoms...

How familiar are you with tuning 2-strokes? Is the surging / wavering you are describing different than the miss that occurs when a saw 4-strokes at high rpm from being a little rich?

Did you clean the fuel filter or air filter?

 

[Jeffbecky1]

I'm quite familiar with tuning 2-strokes. This saw is not 4-stroking. It's just going up and down in revs while I have the throttle pegged. New fuel filter, air filter is clean.

 

[Czed]

Seals bad will do that
At idle turn the saw over see if it changes speed or quits.

 

[huskyboy]

Air leak somewhere probably.

 

[Barfly]

Air leak somewhere probably.

Check the 4 cylinder retaining bolts underneath the saw.

 

[Jeffbecky1]

It idles fine at any angle. bolts are tight, I'm going to replace carb today and see what it does. I've heard that some of these carbs have worn shafts in carb and suck air in through there

 

[beaglebriar]

I'm going with bad coil or poor tune. A video would help a lot with diagnosis.

 

[Jeffbecky1]

I'm going with bad coil or poor tune. A video would help a lot with diagnosis.

I kind of wondered about coil I’ll try to get a video of it tonight

 

[beaglebriar]

I kind of wondered about coil I’ll try to get a video of it tonight

A lot of the time if the coil is going it'll be all over the place at full throttle but never really achieve it and it will be fine at idle.

If it were an air leak it will be slow to return to idle and normally the chain will continue to spin. Achieving WOT isn't a problem other than it's in a lean condition which will kill the motor real quick.

I'm gonna guess a carb swap won't cure your issue but it absolutely could.

 

[KYsawman]

I kind of wondered about coil I’ll try to get a video of it tonight

I have some unlimited husqvarna coils if you want to try one, I am in Scott county too, you’re welcome to grab it to test. Shoot me a PM.

 

[Jeffbecky1]

I have some unlimited husqvarna coils if you want to try one, I am in Scott county too, you’re welcome to grab it to test. Shoot me a PM.

Thank you for taking time to let me try the coil. When I got home I replaced the carburetor and it runs great. I don’t think it was the coil after all.