Dolmar 420sc problem & various questions

[Stere]

Got it off with a homemade tool made from a 3 ft length of wood with 3 nails stuck in the end so had plenty of leverage

 

Loads of black gunk underneath

 

I think the worm on mine has worn shorter either end as it seems short of the lugs on the bottom of the sprocket so they don't seem to turn it.

 

Here  is a picture of  the part from the  internet  "worm" or PUMP DRIVE  181 245 090

 

 

Is this usually the bit what wears out?

 

 

[Stere]

Part above  came from germany & now its oiling fine.

 

Idle is  fast when saw gets hot though (had too re-adjusted down)  hoping it will settle down after running a  few tanks of fuel though the saw.

 

Got that new 95TXL  064G  oregon  chain on  its really grabby cuts like crazy gotta be careful with it i reckon. Its not the best  for smaller diameter stuff abit too fierce, but really fast on large stuff.

[Sawchip]

2 hours ago, Stere said:

Part above  came from germany & now its oiling fine.

 

Idle is  fast when saw gets hot though (had too re-adjusted down)  hoping it will settle down after running a  few tanks of fuel though the saw.

 

Got that new 95TXL  064G  oregon  chain on  its really grabby cuts like crazy gotta be careful with it i reckon. Its not the best  for smaller diameter stuff abit too fierce, but really fast on large stuff.

50.1 synthetic oil "only" or Aspen and then....If you have a TACH set the idle at 2500-2600 when warm/hot with the L"  (low running needle) side on the carb ...ie slow the motor a tinny bit at idle with a little more fuel rather than just backing down the idle screw. The ps 420 tends to idle fine around 2500-2600 rather than 2800 ..then when the motor really gets hot you tend not to get a significant lift in rpm. The Zama carb is fairly sensitive so take note of your baseline positions before you start.