Oil Leak
 

I have a oil leak that I can not find on my Roketa 167fml 200cc engine. It seems to come from the front sprocket cover ,but when I pull ithe cover no oil. It started after an oil change, so thinking it was the oil screen cover, I drained the oil after a ride and re-assembled the cover. It's still leaking. No visable leak higher up. Anyone had a similar problem with the 167 engine? Maybe a quarter size spot on cardboard, but with 600 miles on the engine I didn't expect this.

Do you have a skid plate? some old oil might have gotten trapped there.

Probably from the skid pan. Or, might be chain run off if you recently lubed the chain.

Chain was lubed over 100 miles ago with a wax lube and no skid plate. I know it's not alot of oil, but it has been a consistent leak for the last 100 miles.

Well then about all you can do is get everything spic and span clean, fire it up and look for leaks. Unless there's an oil fairy in your shop, it's gotta be coming from somewhere.

What kind of oil are you using?

Take a piece of 35mm film negative, slice the side off of it so you get something resembling squared-off saw teeth. Then cut the whole strip narrower to make it easier to work with. It may take a few cuts to make just the right tool.

Work this between the output shaft and it's oil seal, in kind of scooping motion, go all the way around. Remove the front sprocket and spark plug, you may find it is easier to work the film in if you ease the engine over while in gear. Chances are there is a bit of trash in the seal, and your aim is to pull it out with the "saw teeth".

Works well on leaking fork seals, since they are larger diameter, you needn't cut it too narrow

Rotella 15w-40w, MCB thanks for the info, I'll give it a try.

Found the leak. Some sort of electrical sensor with two phillips screws holding it, had a bad o ring. Sensor was just foward of the front sprocket. The o ring still had mould flashing. 49 cents for a new o ring. I'm finding this bike is a challenge in a fun garage kind of way.

That sensor is the crank trigger for the CDI. So the o-ring was sealing off the 2 bolts that hold the sensor to the crankcase? I'm not sure why there would be oil passages next to that sensor???

Isnt there a gear indicator switch also located just forward of the sprocket?

Whatever it was, glad you spotted it and it was an easy fix.

I got an absurdly large assortment of o-rings at Harbor Freight, nice to have around!

That was my thinking also. At least the bike runs and I am not trying to keep a 30 year bike running.

The tech level on these is within my abilities.

Allen

The sensor has an o ring on its engine side. When I removed it a small amount of oil was present and it looks like there a hole that goes deeper into the engine case. So far its still holding after 20 miles.

Ah, yes OB1!! That could well be it. That would make sense why it was sealed! You da man!!!