husky 3120 wont rev right

[chainsaw surgeon]

can anyone help with husky 3120 ,fitted new piston and pot, starts fine but revs at top end sounds like its running rich,can anyone tell me how to tune it as it has only one adjuster on carb

[Stubby]

Spud will be along , fear not !

[chainsaw surgeon]

thanks i hope he can help

[spudulike]

The 3120 has a fixed H jet and you can only adjust the L jet. If it is running rich at the top end then I would suspect something is wrong with what has been done!

 

Has the carb been apart since the repair? The first thing I would check is the metering arm height is correct.

 

Is the saw fourstroking at the top end, how did the piston/pot fail in the first place, has the route cause been found, is the P&C OEM or aftermarket?

 

Good luck

[mixedangased]

whats it like with the air filter off?if its ok then fit a new one,they seem to be very fine and block easily also if they are damp will do the same,

[chainsaw surgeon]

Hi the piston and pot failed because someone had put a peace of chain file in the inet manifold

The saw runs fine up to half revs and seems to miss fire a bit

[spudulike]

Hi the piston and pot failed because someone had put a peace of chain file in the inet manifold

The saw runs fine up to half revs and seems to miss fire a bit

 

The misfire could be loads of things from fuel to ignition etc, was the new P&C OEM - the Chinese ones can be hit and miss on bore to cylinder fit, squish and port bevel and timing!

 

If you do a decent size cut, what colour does the plug go?

 

As a previous post, if the air filter is removed (leaner running) does it rev out better?

 

It may be an air leak causing bogging or too much fuel!

 

Is the L screw on factory, if you leave it on idle for a few minutes then give it a load of throttle, does it smoke a lot?

 

If the saw ran fine before the file episode (am guessing the file broke and messed the bore???) has anything else been done or just a new P&C fitted.