Was just out for a test ride on a somewhat freshly rebuilt ski. Had it seize up on us out on the water. Got it home and started ripping into it and found that we could get it cranking again after it cooled. Noticed an air pocket in the oil inject line so I pulled pump and turned with drill. Can’t get it to pump unless it’s basically past wide open on the throttle. Swapped it out with another one and that one seems to be doing the same. Having the pump lined up with the marks I can’t get it to pump a single drop at 2000 rpm on the drill. Any suggestions out there? Has new filter and XPS 2 stroke oil. Tested the pump completely off the ski by filling the oil line with oil.
787 oil pump issues
- Thread starter tingraham
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kenfyoozed
Member
Was the one you swapped it for a new one? or just another used on off another engine?
GGuillot
Well-Known Member
You're spinning it counter clockwise correct? It pumps almost nothing at idle when the marks are lined up, it relies upon residual oil inside the engine. You need some resistance to get it pumping, I run them on the bench as an assembly of the pump and RV cover, lines and all, without touching the pump arm, it'll prime and come out the brass fittings at the RV cover pretty heavy. Then lines still intact, install the RV cover and pump, connect the supply line and open the little screw on the pump to bleed the air out.
Then adjust the oil pump according to the SM, throttle plates closed and synced,then 2 turns on the idle screw then align the pump lines. Should be very little turning the idle screw to fine tune the idle, then recheck the pump alignment.
noviceskier
Active Member
Pretty sure to bleed the pump all you do is crack open bleed screw turn the arm at "WOT" while the engine idles till you see no more air in the lines then close the bleed screw and adjust the marks from there.
GGuillot
Well-Known Member
Everyone has a technique, mine is to not do any of that with the ski running, it's done all prior to starting to remove any doubts. When I crank for the first time, there's no air in the lines and I've confirmed it'll pump.
noviceskier
Active Member
There is residual oil inside the engine and will lubricate it at idle, but I understand your caution.
To the OP you should always be premixing a new engine along with the oil injection.
To bleed the pump open the bleed screw with the engine off until you get fresh clean oil and no obvious air.
Then with the ski at idle (3000 rpm out of the water) hold the oil pump arm open, you will get a lot of slack in the cable so make sure the ends don’t pop out of their ends. You should see the oil slowly pulsing into the little 3/32” clear lines. It only moves about 1/8-1/4” per pulse even holding the arm wide open at 3,000rpm idle.
To bleed the pump open the bleed screw with the engine off until you get fresh clean oil and no obvious air.
Then with the ski at idle (3000 rpm out of the water) hold the oil pump arm open, you will get a lot of slack in the cable so make sure the ends don’t pop out of their ends. You should see the oil slowly pulsing into the little 3/32” clear lines. It only moves about 1/8-1/4” per pulse even holding the arm wide open at 3,000rpm idle.
Alright folks, thanks for all the replies! I bench tested 3 oil pumps I have including the one that was on it (all used pumps, not new). 2 out of the 3 worked about the same where they pumped virtually nothing with the marks lined up but when you get about 1/8” or a little more passed the mark they would start pumping a bit. The 1 pump that acted different was the pump that was on it which I had to rotate it to roughly at least where it would sit at full throttle, if not more to start putting any oil out. It would put the oil out at a decent rate once it started. Apparently I have discovered the one pump ever that has failed. All the pumps were properly bled before the bench test by actually blowing into the oil line with my mouth to force the air and oil out of the bleeder.
Thanks for the tip on premixing for the first tank, I’ll go ahead and do that before next test ride.
Thanks for the tip on premixing for the first tank, I’ll go ahead and do that before next test ride.
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