igotta 02 honda 400ex has lex exhaust and uni filter and i was running 20 50 weight oil and it was smoking horriably and then i switched back to 10 30 weight gtx not synethic and now it smokes a little but eats the oil idk wut to do please help it smokes and it smokes bad sometimes but not bad other times wen i ride but the heavyer weight was terrable so i need help

 

Does it feel like there is any power loss. When i had my 01' ex it started to smoke white one weekend but i did nothing then the next i was told it was smoking bad so i checked the oil and it had burn't all the oil. So i refiled it and after that weekend it had alot less power so i took it too my dealership it was'nt seized but the engine was worn bad and i needed it rebuilt. if any of this sounds familiar it could be you valves or piston possibly.

 

Sounds like piston rings, might be time for a top end rebuild.

 

It is my understanding that if it smokes on start-up and then clears, it is the valve guide seals.

Smoking that doesn't stop is the rings.

Might run a compression check to verify the rings are not sealing.

 

Seems to be a common thing on the 400EX's. Nearly all of them smoked a little and quite a few smoked like a train. Most likely a top end rebuild will take care of it.

 

Rings bro, rings