Husqvarna Rancher 455 idle running problem

[westriver87]

I am new to the site and have a quick question for y'all. I just picked up a Rancher 455 for a good price. Looks like new and only a couple years old. The problem is it starts and runs fine when the choke is on, but when you turn the choke off the engine speeds up to almost full throttle. It speeds up so much it engages the clutch. I am thinking it has an air leak somewhere. Is there any places that are common to leak air on these saws before I get into it? Do y'all have any other ideas? Thanks in advance for the help.....

 

[Stihlbillie]

Husqvarna's have a high idle switch that is set when the choke lever is pulled out and once the saw starts you blip the throttle to set it back to idle. I don't know if thats the problem your having? Or the idle screw is too far in. If not it's probably an air leak around your crank seals.


-chimpboy

 

[westriver87]

I have two other 455's and this problem is new to me. I am aware of the choke/high idle function. What all is involved in changing crankshaft seals on this thing?

 

[Stihlbillie]

Replacing crank seals basically means complete teardown and cleaning everything along the way. I think a guy on this site has a video of a 455 being rebuilt.


-chimpboy

 

[Stihlbillie]

It could also be a cracked intake boot.


-chimpboy

 

[Mattyo]

Is the idle screw too far in?

Is the low screw too far in / defeated?

Intake boot could be cracked. ..loose...crankseals bad...bottom gasket bad...etc

 

[Stihlbillie]

Oh yeah it was mattiyos video.


-chimpboy