Engine Issue

[afarkas]

I just purchased a 2001 Yamaha Zuma at an auction a month ago and everything appears to be working great. Actually, this little bike has been running like a raped ape until today.
I was running at full throttle for 10-15 minutes when the engine started to flatten out. I stopped, started back up and it ran great for a couple of minutes and then flattened out again. This happened a few more times and then seemed to correct itself, but it seemed that the engine just didn't have quite the power as before, almost unnoticable though.

So, I've got the following questions:

This bike is a 2 cycle that automatically mixes the oil with the gas, but I haven't noticed much oil being used. After running a couple tanks of gas I thought that I'd notice more oil used, but the oil level in the tank doesn't seem to have moved much. I didn't think too much about it because I can see a little light smoke coming from the exhaust when the choke is on. Here's the question: How much oil is used or what is the rate? I'm wondering if the oil pump is working properly.

I don't know how long the present spark plug has been in use. Could this be the problem?

[speedy_scooter]

Easy way to find out if the injector is still working, pull the plug, if its got like little or no oil residue then the pump most likely isnt pumping all the way. If the plug has a black residue tehn the pumps working. It all depends on the plug color.

[Zuma_Man]

so the spark plug is supposed to have oil on it?

[speedy_scooter]

It should have a bit on it yes. You dont want it to be dripping off or all gunked on but you want a little burned on layer.

[mickgoblin]

Your plug should be chocolate brown on the firing portion of the plug. You may just try a new NGK plug for it and make sure you gap it between .6 & .7mm if you have a 49cc Zuma. Thats the factory yamaha gap in my service manual for a 2005. Check your plug again after a ride and look at the color. On this site they have a plug chart to show you whats good and whats bad as far as color and wetness goes.

[rydah]

when you first start your engine does it smoke a lil, if not your not getting oil in your engine.

[Zuma_Man]

my engine smokes quite a bit actually, I think i'll do a plug read, the last time I did it, it was like golden brown, but not chocolate brown. have you seen the ngk charts, lol. I was looking at them..I was like wth..?

[afarkas]

Yes, the engine smokes a bit at start up.

I took it up to the repair center and on the way after about 15 minutes it lost power again. The engine just flattened out with the throttle wide open. I pulled over and then started again making it up to the center, but there was a bit of a loss of power.

The repair guy said for $90.00 they would change the plug, adjust the carb and oil injector, check tranny oil and give it a once over. He also stated that it could just be a blocked exhaust, so I thought that it would be money well spent.

I got the bike at an auction for $75.00 and don't know if it's ever been serviced.

[ScrappyScooter]

The oil injector can be adjusted?

[XPS1210]

the oil injection on these are fixed... however I opened mine up the other day and I think it might be able to be controlled a little via larger or smaller tension springs in it... but not sure