064 wont idle properly, and throttle unresponsive

[chiseltooth]

Hi all, bit of advice needed here.
this 064 i got started fine but kept dieing. fiddled with the high lows and now it idles, but runs away with itself when i press the throttle. when i release the throttle it takes an age to slow down.
the hi screw is turned full in clockwise and backed off about half turn, while the low is about 2 1/2 turns backed off. i dont have a manual, but on my litlle 254xp it didnt take long to suss out the right settings by feel.
can anyone take me thru set up with some good instructions.
really appreciated.

 

[Bowtie]

Have you done a pressure and vacuum test? That sounds like an air leak.

 

[chiseltooth]

Dont have the kit or know how to do that to be honest. air getting in where?

 

[RiverRat2]

Have you done a pressure and vacuum test? That sounds like an air leak.

Yep!!!!!!!!

 

[chiseltooth]

what exactly gives it straight away for you guys that its an air leak? whats needed to fix it. if its a big job then i'll return the saw to the seller.educate me please.

 

[Dan_IN_MN]

The saw should get all of it's air through the carb

what exactly gives it straight away for you guys that its an air leak? whats needed to fix it. if its a big job then i'll return the saw to the seller.educate me please.

The clue is that the carb adjustments aren't doing what they're suppose to. If the saw is sucking air into the crankcase through the crankshaft seals, you are going to have to turn the L screw up more to give it more fuel to match the additional air to get it to idle properly....if that is possible with a leaky seal. The saw should get all of it's air through the carb and that air should be mixed with fuel.

Is it a big job? Well it involves taking the saw just about all apart. In some case, a seal leaks because its old or because the bearing is bad and the crankshaft isn't held in the center of the seal so there is a gap around the top of the shaft where the seal is leaking. Is that a big job to you?

The leak also could be in the carb mounting gasket or intake manifold.

Dan

 

[Lakeside53]

yep...