sthill FS450 Vibration

[simonRribeiro]

hi

 

I have a fs450 that works and runs great but has a vibration that I can feel through the handle bars and the hole machine in general.

I have swopped the head from another machine and it is still there, I have fitted a new drive shaft and shaft liner and the vibration is still there.

 

the vibration is bad enough that using the machine for more than 15mins becomes uncomfortable/painful.

 

I am now thinking that the crankshaft may be bent !

 

just wanted any second opinions before I start tearing the engine apart

 

any help would be much appreciated !

 

 

thank Simon

[garth mc garth]

What's the clutch like? I'm guessing it can't be too bad if you have had it apart already to replace those bits

[Millbert]

Hello

 

Have you checked all engine mounts?

[simonRribeiro]

I have checked the clutch and the engine mounts, and all look good

[Richard 1234]

Has the gearbox on the head got grease in it?

[spudulike]

A bent crankshaft would either make the engine not run or would significantly scuff the cylinder bore pretty quickly!

[simonRribeiro]

the head does have grease, I replaced the bearings in the head first but it was still the same so I then managed to use a second head from another machine but that also made no difference

[simonRribeiro]

my thinking on the crankshaft is that it is bent on the output part where the clutch fixs on

[harrythecat178]

Have you checked bearing around the clutch drum, especially if you have a whirring noise

[simonRribeiro]

yes, I have also changed that bearing, you mean the one actualy in the drum_