OPT,

If I do that and it IS flowing oil, is it an all-or-nothing deal? In other words, how do I test if enough oil is flowing? There is an in-line filter on the oil line which I would replace before I tested this. Also, I think my oil line is opaque so I wouldn't be able to see oil flowing...

Then, since I premixed I would imagine I would want to cap the oil tube until the first tank of fuel is just about finished as I would not want run premix AND inject oil...at least not for long!

 

Just loosen the 10 mm bleed screw on top of the oil pump and let the oil flow out a little to clear any possible air bubbles. Pull the oil line from the base of the cylinder,plug the nipple at the cylinder with a rubber plug. Since you have the tank premixed it wont be any danger to it. Crank the engine,at an idle lift the pump lever arm all the way up. This just tricks the pump into pumping like it was at max rpm. If the oil trickles out,the oil pump is fine.

 

OPT,

Fired it up tonight with the new top end. Heard a lot noise like something was loose, vibrating (you know how these 2-cycles run). Sounded like the oil pump so I lifted the pump lever like you suggested and nothing seemed to change. I would have thought I would see white smoke from being oil-rich.

So I think the chattering sound is the pump going or gone. I shut it off. I will cap that all tomorrow and run straight pre-mix. At least for the first tank during break-in.

After that, I will again look at the pump using the method you posted. In the meantime, I plan to simply drain the oil tank and cap the hose (keep debris out) and put a cap on the oil pump intake nipple.

Is anything else required for this? thanks!

 

Noise could be radiating up from the crank bearings or rod bearing if you just did a top end only. Al you have to do on the pump is pull the line from the cylinder,block the inlet injector with a rubber cap plug and lift the pump arm up as the engine idles. If oil comes out the hose the pump is ok.The noise you hear may be something else?