Yanmar 1gm10 Performance Problem

[michaelmrc]

well still no luck in determining the cause of this issue. engine will not get past 3000 rpm now and surges down to 25-2600 when surging i find that if i crack open the bleed screw on the injector pump it revs back up to around 3000 but will slowly creep back up and down. almost as if air is getting into the system. im curious if it could be a defective diaphragm in the lift pump i priced out a new one here $219 pretty steep. i was thinking of replacing with a walbro electric pump any thoughts or recommendations. this one looks reasonable.
Walbro - Marine Electric 4PSI Fuel Pumps 12 & 24V

[rtbates]

Do you have a single lever control?

If so, could be the control cables..

[michaelmrc]

no i have twin lever thottle and shifter

[Chief Engineer]

$219.00 for a Yanmar Lift Pump??????

They cost less than a Hundred down here.

[michaelmrc]

must be nice $219 canadian funds i thought was outrageous. an electric walbro is $100 less and probably better.