Motorcycle Repair: pw 50

Question
QUESTION: Hiya again in the last few days have totaly removed oil pump from my sons bike seems to be ticking over and revving fine but i am still having problems with the bike smoking and also shes still spitting oil through exhaust although not as bad as before is there something elsr that i could be over looking or does the bike need a good run to push the ramaining oil through the exhaust. Thanks

ANSWER: Hi Rossco,

Sorry for the delay. It was a very hard racetrack weekend. I just got home.

Of course, there will be a lot of unburned oil in the exhaust that must be burned off...
This can be done either by a REALLY GOOD run, which will make it red-hot, or, by a powerful
propane burner, and, understanding and patient neighbors!!!
At this point I must say, that, if you are using a fully synthetic, high performance
two-stroke oil, DON'T...!
Competition oils take high performance competition engines to be efficiently burned.
You're not doing any good if you're using them on a PW engine.
Follow OIL manufacturer mixing ratio, and prepare the fuel in a proper container
(not the fuel tank) making sure you stir and shake thoroughly.

Assuming you've checked the thinks I mentioned in the previous answer, I apologize if I offend
you by suggesting novice checks, but I can't be aware of the questioner level.
That said, I look forward for your coming back with an update...

Best Regards,
Lazaros.
    

---------- FOLLOW-UP ----------

QUESTION: Hi again i am still havin bother with this bike after a week of trying to push this oilthrought the system i have turned to premix and i am still getting nowhere to resolving the issues i notice that when cleaning the spark plug it was jet black and oily when looking down the top end i notice a load of oil splashing round in there. I then got in touch with previous owner who told me he was using a high performance racing oil pryer to me buying it so is this just oil that hasnt been burnt being sucked through the pistons or should i be starting to get worried sorry to trouble you again and thanks.

Answer
Hello Rossco,

I think that if it was old oil trapped in the crankshaft chamber it would be gone by now...
Check crankcase once more by making sure that there is no vacuum building up in the transmission and that trans oil isn't getting low...

Regards,
Lazaros.