Smoking

[ktoom]

when i start the bike up for the first time, it smokes . Once i ride it though it goes away and never comes back for the whole race or ride. It only smokes when im warming the bike up from a cold start or when it sits for accouple days until i ride it again. I recently had the whole motor apart and installed new gaskets and put everything back together my the manual. The bike dosen't lack power or anything. Any thoughts?

[356]

Piston rings....

[dvn]

Maybe valve seals?

[mwmx54]

why did you take it apart?? it could be valve seals or piston rings. but the reason it smokes is because oil is somehow making it to your piston.

[356]

Ya I meant to mention the valve seals to. Sorry I was in a hurry. Yes the reason it is smoking it b/c oil is making it past the piston. Replace the rings and valve seals. Total cost would be about 30 bucks.

[ktoom]

I look it apart cuz there was a gear problem. I think its the valve seats cuz when i had it apart, i put new rings in it. when i started it up after i put it back together, it was smoking then. I find it weird how the valve seals would all of a sudden go bad after i get the bike back together?. Wouldn't the oil in the cylinder make it run like crap though?

[chewy619]

If you took it apart, and re used the vavle seals, u wasted yur time, they turn to junk once u take the vavle outta them and re use them, had the same thing happen to mine, jsut put new seals in and they were fine

[OldSlowMXer]

Valve seals. No doubt. Smoking on start up is because oil will make it past a bad seal when the bike is sitting. Not all of the oil drains out of the head when you shut it off and some will leak past the bad seal. Once you start it up the oil burns off and everything is good. I wouldn't worry about it unless it gets really bad.

[ktoom]

I never took the valves outta the head though. I only took the tranny all apart. It boggles my mind that they would all of a sudden just go bad when i put the bike back together?

[motoxbluedog]

These bikes had a tendency to smoke when they intially start up. Once everything is warm it settles and no more smoking. Unless your creating a smoke screen around the track I wouldnt worry about it. Both of mine do it.

[ktoom]

KK, cool. Thanks boys

[gray151]

What color is the smoke? If mine is cold and i start it for the first time in a while, with full choke, you might get a small bit of black smoke if you pop the throttle, real rich fuel/air mixture, but you would expect that with the choke on, if its that its normal, if its blue i would look into it.

[Cyclepop]

Im with motoxbluedog, mine smokes a bit when starting, probably due to choking??? However after it is warm it is fine. It did this prior to a new top end and after a complete top end overhaul. If it stops after warming up, I dont think it is a problem.

[kelstr]

when i start the bike up for the first time, it smokes . Once i ride it though it goes away and never comes back for the whole race or ride. It only smokes when im warming the bike up from a cold start or when it sits for accouple days until i ride it again. I recently had the whole motor apart and installed new gaskets and put everything back together my the manual. The bike dosen't lack power or anything. Any thoughts?

well ,you did not prep the cylinder to seat the new rings, ( the valve seals are fine),

you must hone it and assemble it dry in order to get the Rings to seat,

if you just put rings in the glazed cylinder and oiled it going together ?? ,

the rings wont ever seat and it will go through oil and contaminate the combustion chamber and will hurt the valves !

[OldSlowMXer]

well ,you did not prep the cylinder to seat the new rings, ( the valve seals are fine),

you must hone it and assemble it dry in order to get the Rings to seat,

if you just put rings in the glazed cylinder and oiled it going together ?? ,

the rings wont ever seat and it will go through oil and contaminate the combustion chamber and will hurt the valves !

I'm not so sure about that. I think these cylinders have a Nikasil plating that is very fragile and will be damaged if you try to hone it. I'd check with the dealer first.

[Fly5150]

My X has a little smoke on startup. My TTR also does this. I think its because the choke is on and making the engine rich till I turn the choke off. This is the only time it ever does it, on startup with the choke on. Never with the choke off. I wouldn't worry about it.

[kelstr]

I'm not so sure about that. I think these cylinders have a Nikasil plating that is very fragile and will be damaged if you try to hone it. I'd check with the dealer first.

nope !!---you must hone any cylinder to brake the glaze, ( i don't care if it is iron nikilsal chrome )----( you wont get these questions answered from the guy at the dealer , or the manuel )

if you dont believe me --ask " BURNED " he has a long history of high HP engine building , as so do i and proper cylinder prep is so important , ( it takes along time to correctly set up hone and really wash and clean all the top end componuts for correct assembly )

you could hone a nikilsal cylinder all day long and not hurt it ? ,

you must give the rings something to bite into and seat ,

you can't oil the cylinder or rings at all on assembly or you will never get the thing to seal and work correctly ? ,

its been this way for ever in engine building ? .

oil must not get into the combustion chamber at all,

proper cylinder prep a dry build and slowly turn the motor over quite a few times and let the rings bite the nice dry fresh honed cylinder is how you really get the cylinder seal to keep making the most use of combustion and not have blow-by .

when you get oil in the combustion chamber you cause so much engine dirt and this keeps the valves from seating correctly and they overheat and die ,

not to mention you are contaminating the crankcase oil from all the blow-by and contaminating the fresh fuel charge and making less power

its just one of those things you learn .

the pump fuel is bad and dirty enough ( you really should use race fuel -----but we wont go into that ---yet )

[ktoom]

But then why does my bike run fine? I didn't know u were suppost to hone the cylinder? I only say that cuz i know alot of people who put in new pistons without honeing the cylinder. It would make perfect sence, as u explained. What can i buy to hone the cylinder myself?

[Kx250FRiDeR651]

hydro carbons

[kelstr]

But then why does my bike run fine? I didn't know u were suppost to hone the cylinder? I only say that cuz i know alot of people who put in new pistons without honeing the cylinder. It would make perfect sence, as u explained. What can i buy to hone the cylinder myself?

A flex hone , or dingle ball hone as they are also called

most guys have quite afew of them to hone about everthing on a bike, pistop pin bore , cam carriers, bucket bores etc.

they are cheep and come in sizes from 1/2" too 10"

i use a 3 1/2" to 4" 240 grit flex hone for most all the 2 stroke and 4 stroke bikes