Adjusting Oil Pump on GT250

[Nomadmax]

I have a technical manual and have adjusted my oil pump on my GT250K as specified. At WOT (or near it) I get a fair amount of smoke. Should it be adjusted like the manual says or do modern 2 stroke oils cause it to run a little rich? It does smoke pretty good after sitting which would indicate (from what I've read here) that the check balls in the oil fittings are stuck open. But even after that, it still smokes pretty good. The bike idles good, isn't hard to start and the trans oil is still all there. I guess I just don't remember my old bikes smoking that much.

[oldjapanesebikes]

How much have you ridden it ? I ask only as any of these bikes that have sat for a while load up with oil in the pipes and crankcase which will not clear out until you've had on the road for a while and got everything well warmed up. If you have only had it running in your shop or driveway, then I'd hold off till after you've burned a tank of fuel on the highway before thinking about changing anything.

[Nomadmax]

I've ridden it some, a few tanks full anyway. I was reading in another thread here that the marks to line up should be at WOT. I lined mine up (according to the manual) at closed throttle so when you go to WOT the arm goes past the second mark. I may just go align the mark for WOT and see what that does.

[oldjapanesebikes]

I've ridden it some, a few tanks full anyway. I was reading in another thread here that the marks to line up should be at WOT. I lined mine up (according to the manual) at closed throttle so when you go to WOT the arm goes past the second mark. I may just go align the mark for WOT and see what that does.

Not 100% sure about the GT250, but suspect it can't be too different from the T250 - actually just looked at the Clymer manual and they say it is the same, so how be you take a look at the shop manual ? I have the T250 one on line at this link.

[Nomadmax]

That was very helpful, thank you. I adjusted the pump so that the marks lined up at WOT and got less smoke. I'd say I'm gonna have to do something about those ball bearing check valves in the oil line fittings though. My guess is they're stuck open and letting oil in when the engine is off.