I have a newbie question for you.

I'm considering buying a 2004 TTR600RE whose engine has 11k miles on it (not the original engine though).

However, the owner has said it burns about a pint of oil every 400 miles on the freeway, which doesn't seem to bode well for any long distance trips in remote places (I'm planning a "RTW"-type trip).

The owner also points out that "The bike sometimes lets out a puff smoke from the exhaust on starting so the valve seals are worn its not a problem did a 1500 mile trip last september."

Are the valve seals the likely culprit? What else could make this bike burn oil? Would a mechanic, upon breaking open the engine, be able to say definitively whether the valve seals or piston ring or anything else are at fault? What would the ball-park cost for replacing the valve seals and piston ring be? (closer to $200 or $500?) How likely is it that the cause of the oil burning would not be properly diagnosed?

If worst comes to worst, what would a ballpark cost for an engine rebuild / new engine plus installation be, and how much time would those take?

Normally, I'd look for other bikes (and I am still looking), but the bike market where I'm shopping is quite small and the TTR is relatively inexpensive and seems to fit the bill in almost every other way. So if a valve seal / piston ring replacement would probably do the trick, I'd go for it. I'd appreciate your thoughts.

I dont think its only the stemseals, if it was using half, then maybe. My guess is both the seals and piston/pistonrings.

Rough numbers:

Piston with rings 150$
Complete gasketset inkl stem seals 60$
Machinework for cylinder 75$ ish..?
Camchain (while you're inthere) 50$
Oil and filter 30$

And then a handfull of hours for a mechanic

I dont know the going rate at your location, but for me in Denmark if wouldnt make any sence to pay a mechanic to do the work, its just too expensive.

Can you get help from a friend ect...?

Otherwise just ride the bike, and add oil. If you go a bit slower than freewayspeeds, the oil-use should drop to some.

If you can have a compression check done it can tell the mechanic if the rings are bad(at that oil usage, compression will be down). If compression checks out good then the seals can be changed fairly easy with the right tools, but usually the head has to come off, so as long as it's torn down that far then new rings and piston is a good idea.

$500 is a light number for having someone else do it. If you could do it yourself that price is easily doable for a complete job.

Thanks for your responses. I will inquire about the compression test.

When people say "replace the piston rings," does that always entail a piston replacement too, as well as reboring the cylinder? Was hoping the rings could simply be replaced (but I understand those rings require quite a bit of work to get to).

Also- just how bad is losing 1 pint of oil per 400 miles at highway speeds? Is this in the normal spectrum? It seems to be on some bikes, but seems high from what I've read about the TT6000 / XT600. My impression was that once you start burning a fair amount of oil it progresses quickly, which is why I'm looking into this- is that accurate?

Thanks again for your insights.

I think it depends what is found when the engine is stripped down; measurements can be made and compared with the specifications.

That's a lot in my view; I owned a TTR600 about 9 years ago and it did a lot better than that on oil consumption - I can't remember any specific figures though.
Bear in mind that it is a dry sump design of engine and you need to check the oil levels properly and accurately.
Overfilling with oil is nearly as bad as a low oil level.

Again, I would say that you aren't far out with that statement - it does depend on a lot of variables though, including exactly what is wrong with the engine and how long it has been "misbehaving".


I tore into my engine myself and learnt a lot from that; enough to know that there is a learning curve in play and it takes time and effort to learn on the job (that was for changing a leaking base gasket).

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Dave