I have a 1991 kdx 250 (just bought) even when hot the bike blows smoke (quite a bit when cold), oil lightly spits from the exhaust and leaks from around the connection of the exhaust to the barrel. The bike appears to have plenty of commpression and is quite crisp in the powerband. Is this normal ?.I am running castrol TTS fully synthetic oil at 32:1 I have noticed articles in this forum about oils and how the use of some oils needing power valves to be cleaned. Would this cause exhaust smoke if so whats involved in cleaning the power valves. The exhaust is a pro circuit.