Increasing MS290 Oil Pump output

[FlyingDutchman]

I have a 390 kitted MS290. It has always oiled poorly. The chassis is pretty old, oil pump is original but looks perfect. Been taken apart multiple times and cleaned, checked, and cleaned and checked again, It only goes through about 1/2 to 1/3 tank of oil in a tank of fuel. Its on the max setting. Running 325 .63 ga chain on a 20" Tsumara bar because it cooked the old bar and its what I had handy.

Is there a way I can increase the output of the oil pump to run a 25" bar or at least competently oil the saw?

 

[RED-85-Z51]

Be tempted to try a new oiler. My ms311 oils a 25" no problem.

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[FlyingDutchman]

This is a grandaddy MS290, square top. Almost an 029. I had read that there was an upgrade pump for these but haven't been able to find it. A 311 is at least 20 years newer. Not sure if they share the same architecture anymore.

 

[RED-85-Z51]

This is a grandaddy MS290, square top. Almost an 029. I had read that there was an upgrade pump for these but haven't been able to find it. A 311 is at least 20 years newer. Not sure if they share the same architecture anymore.

I has an 029Super, and a pair of 290s in last week and 2 had 25"s ans one a 20". The all seemed to oil pretty aggressively...made a real mess on the bench quickly.

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[HarleyT]

Here, this might help..

 

[user 122190]

Maybe run a thinner viscosity oil?

 

[FlyingDutchman]

Even with 50% gasoline in the tank, it still isn't oiling right. I think the eccentric at the end of the gear/piston (near the numbers 1 and 2 HarleyT's post) must be worn down. I was looking for debris or physical wear in the piston/bore.

 

[FlyingDutchman]

Does anyone know the likelihood that I will need a new oil pump body to go with the piston when I get it?

 

[dmb2613]

11276403201 is the entire pump , go with that

 

[FlyingDutchman]

Dealer had the part number that dmb2613 mentioned in stock paid $46.50. The part number was superseded they said but did not list the actual part number on the invoice. The guy who has the saw says it oils great now.