oil consumption

[jermzfree]

Got an 03 busa with about 10k on it. It seemed to use around 1/2 quart every 1k miles. I don't see any blue smoke coming out of the exhaust but it will spit out some black smoke if rev it up in neutral. It also backfires on deceleration with NO mods and stock exhaust. If anyone has any ideas as to what might cause this I would love to hear em.

 

[GIXERHP]

Vavle stem seals, or rings! You would need to have a leak down test done to find out what is is!

 

[jermzfree]

If I had to guess I would say it is the valve stem seals that are leaking. If the valve stem seals are leaking, would the bike puff out a little blue smoke when I first start it up from oil leaking past the valves and accumalating in the cylenders? This bike has all the power in the world so I am skeptical about rings being bad. If valve stem seals are bad, could that also explain the backfireing and black smoke, or are those two totally unrealated?

 

[Burger King]

Have you taken the fairings off and checked everywhere for leaks? It might be leaking only under higher pressure while riding and if you are using synthetic oil it can be a very fine mist that is exiting the engine.
Is the breather hose from the airbox to the engine hooked up?
Have you checked inside the airbox? Is it oil soaked?

The black smoke from reving the engine in neutral could just be carbon buildup.

It's hard to believe that with a 1/2 quart every 1K miles that there isn't a lot of smoke or a noticable leak somewhere.

 

[GIXERHP]

My 04 didn't smoke either, but when i have the motor out, for the big bore, i resprung the valves and replaced the seals at the same time! The seals that i removed were hard as a rock!

 

[Mr Bogus]

Vavle stem seals, or rings! You would need to have a leak down test done to find out what is is!

I would second the valve seals and most likely cause and I would be really suspect of the intake valve seals..

The oil mixes pretty thoroughly with the fuel going in the motor and is mostly burned.

I have seen cars that can do this and the only way to see the smoke is with a projected light source (a good flashlight for instance) at night shot through the exhaust gases..


Exhaust valve seals would cause smoke, rings at 10K would have required a good overheat, run without an air filter, or some other grossly obvious problem barring some type of manufacturing error.

 

[jermzfree]

I guess my next step is to go ahead and do a leak down test, or take it to my trusty bike mechanic and have him do it. If anyone has seen a good thread on leak down tests for the busa, i'm all ears. Did a quick search with no luck.

Thanks for all the great input, much appreciated