MOPED ARMY

Sure, I understand that doing it the way the manual states will work great. I'm just trying to understand for my own knowledge if using my other method has any downsides or not. I can't think of anything for certain, besides getting a bit more oil in the moped for about 100 miles since I'd have premix going through it with some of the oil injection system till it pumps out all the air bubbles, so I'm just trying to see if there is anything technically/functionally wrong with running a tank of premix through it to bleed the oil system automatically. I would think that there may even be a slight benefit to running a tank of premix through with regards to getting all the air bubbles out, but maybe I'm wrong. When I bled the oil injection system myself the proper way, I did end up with one air bubble, so maybe the premix method might be even better? I think about this stuff too much lol.

Thanks for the reply, that makes more sense to me. An oil pump may not have the specific tolerances to pump air bubbles out, but can obviously pump oil since that is what it was made for. Good point. You mentioned that there is a bleeder on the oil pump. I did not originally see a bleeder anywhere in the manual when I did the process the first time. I looked at the manual again and I realize I overlooked a step in the bleeding process originally. Are you referring to the oil control lever that you hold open only while the engine is running to bleed the system?

Ok, I will try out your method to see how it goes. Definitely seems easier than the method in the manual. One question though, when you say to "lightly pressurize the oil tank," do you mean to fill the oil tank with oil? Or are you referring to pressurizing the oil tank in some other way?

I had to do it, I really wanted to try out my premix idea so I thought I'd give it a shot first. I realized the previous owner had installed an improperly fitting oil inlet line, so I replaced that with a clear oil line and while doing that I also checked the port on the oil pump and the port had oil in it so I'm assuming the oil pump was full. I then installed the new clear oil inlet line and left the old oil outlet line alone. The oil outlet line obviously had air bubbles in it since I did not attempt to do anything with it. So I then made sure I had premix in the gas tank and fired the moped up and held the oil control lever open while it was idling. After a second or two or holding the oil control lever open, there were no more bubbles in the oil outlet line (and none in the inlet line, although the inlet line never had any anyways). I'm going to be running premix in the moped for a while anyways and will periodically check the lines, but I think the oil injection system is essentially bled now since I don't visually see any bubbles in either the oil inlet or outlet lines. If I did it the way the manual states, I find that filling the oil outlet line with an oil squirt can is a tad more cumbersome than I like due to the limited space in that area. And the manual obviously tells Urban Express owners to do that because if they just run pure gasoline in the gas tank but have air bubbles in the oil lines, they can starve the engine of oil for sure. So I'm not recommending my premix method obviously, but as of now it at least seems to be working fine. I'll have to check it for a while to see if any new air bubbles form or anything, but I definitely prefer doing it this way over the manual's method.

I agree, I wouldn't want to run more than one tank like that through it. Having a tank of premix in there will give me some time to see if the oil injection system is working properly too, since this moped has not been run in years and at least now I can check to see if the injection system is operational. As of now it seems to be working, but I'll have to check the oil levels in the oil tank to see if they're going down over time to be sure