Husky 455 has issues

[Forrest Arnold]

Hey guys hoping to gain some knowledge without having a possible expensive mistake. Some of you may know that I recently lost the top end in my 55 rancher so when I narrowed my dad's 455 and it was acting a little funny I took notice. Maybe I'm a little gun shy but I'm trying to be proactive. So here's the deal-eo I was cutting some small limbs and such with the saw it started fine and ran perfect crisp throttle no hesitation nothing out of the ordinary I probably ran it for maybe 5 minutes. Shut the saw off shagged some brush. About 30 minutes to an hour later I need to use the saw again fire it up and it's high idleing like crazy so I blip the throttle thinking it might be part of the the cold start feature but it wouldn't idle down. So I take the top cover off to see if the linkage is bound or if there's any obvious funny business going nothing is out of the ordinary. Still running at high idle. So I turn down the idle screw to see if that would do it. The saw now idles the way it should. I am concerned about an air leak since it happened so abruptly but i would think and there's a good possibility I'm wrong that if the idle went up due to an air leak turning the idle down wouldn't have much effect on it. My dad took it to a shop they were 2 weeks out but they started the saw and said it sounded fine to them. Being not so knowledgeable when it comes to small 2 strokes I just want to be sure that everything is copacetic. Thank you guys for your continued help while I try to learn about the art of small engine mechnics.

 

[TBS]

Check the intake boots behind the carburetor because sometimes they come loose or crack causing an air leak

 

[Forrest Arnold]

Okay I'll check there. In your humble opinion does it sound like an air leak?

 

[TBS]

Those boots can actually leak intermittently where they attach to the carb and cylinder insulators. To me it is an intermittent leaks.

 

[Forrest Arnold]

Well I checked the boots didn't pull the carb off the boots are pliable and dont appear to be cracked. There is some residue on the carburetor and boots. I read somewhere about people using carb cleaner to diagnose air leaks similar to the way you find vacuum leaks on a automotive engine. Is this a proven method and if it is what would be a telltale. Would the rpm pick up or would it try to stall?

 

[gasmonkey]

Well I checked the boots didn't pull the carb off the boots are pliable and dont appear to be cracked. There is some residue on the carburetor and boots. I read somewhere about people using carb cleaner to diagnose air leaks similar to the way you find vacuum leaks on a automotive engine. Is this a proven method and if it is what would be a telltale. Would the rpm pick up or would it try to stall?

Check the four 6mm cylinder retaining bolts on the underside of the saw.They must be real tight.Ive seen the odd one missing giving the symtoms you describe.