A forum for owners of Yamaha TTR250 trail and enduro bikes!

TTR in greece · Member

Old TTR Smoking quite a bit... Is it usually valves or rings? anything else to check? cheers

TTRfan · Super Guru

A bit of smoke on start up is usually indicative of worn valve stem oil seals.

If the engine continues to smoke after start up and uses a noticeable amount of oil then its likely rings, and/or a worn or damaged bore.

Only one way to find out! See here

mmwain · Veteran Member

I think if the valve stem seals are gone then there's a reasonable chance this is because the guides are worn. With the valves loose in the guides mine have about 1mm side to side play so I'm getting them replaced. Does anyone know how much side to side play is normal on a TTR?

JOHNYBOY · Super Guru

1mm seems quite a lot are you checking it with the valve just lifted off the seat or with it nearly out of the guide which is wrong the longer you lift it out of the guide it will look like it has a lot of side movement john

TTR in greece · Member

Many thanks for the advice. Winter job I think. I suppose its much easier if I take the whole lump out of the frame and get the motor on a bench?

TTRfan · Super Guru

Not neccessary. Also, easier to work on in the frame if you haven't got an engine stand.

TTR in greece · Member

Thanks mate. Saves a lot of bother not taking the lump out. Just that when I have done other jobs like taken the carb off its a bugger as theres not much room... Is there a manual anywhere? Cheers

TTRfan · Super Guru

A mistake that some new owners make is to try and remove the carb without first removing the airbox. I know it is possible but makes a simple job difficult IMHO.

A couple of videos here.

Steve sells a range of manuals etc here.

Brian