Yamaha TRX850 Enthusiasts Forum

When I recently checked/adjusted the valves on my 96 bike I was able to achieve the required clearances, although a couple of the inlet valves were only just within spec. At some point I will need to replace the inlet valves with the newer version or oversized after market valves. What I'd appreciate advice on are;
- If I fit new, standard sized valves, are the seats likely to need re-cutting or should I be able to just lap the valves in?
- If I go for oversized inlet valves, is there any advantage if I'm retaining the standard exhaust valves?
- Can anyone recommend a supplier of valves - I seem to remember there's a tuning company located in the Netherlands?
- Any issue in fitting used (later) valves?
- Anyone got a set they no longer need, new or used?
Cheers

I ended up buying a later TDM head for £150, just a thought for you..

Had been considering that option but good ones seem few and far between - I'm going to take a look now but so far all I've not seen anything I'd want to take a chance on on 'the Bay'. Seen a few bits which look fit for the scrap yard though!!

All valves wear the seat and the two then marry to create a unique surface. So replacing any valve requires the seat and valve to be matched (cut). Valves are able to be 'tipped', the valve is place in a valve grinder and then tip is ground to give more clearance for the rocker/cam etc. This is usually the last step before replacing the valves for new ones as the seats only require a blight lap to clean them up. Personally I'd buy new valves and get the head striped/cleaned and rebuilt with new guides and seals fitted. If you are able to strip the head and buy all the parts required this will save you $$$.

Looking at a head which I'm told is from a 2000 TDM. I can see from the pictures that it has '3LD' stamped on the head and the valve faces - does anyone know what, if anything, this signifies?

3LD is the XTZ750, but it is the same. I've just checked the pics of the head I put on mine and it has 3LD written all over it.

Snod Blatter wrote:3LD is the XTZ750, but it is the same. I've just checked the pics of the head I put on mine and it has 3LD written all over it.

That's a relief because I've already bought it. Haven't done anything with it yet as my bike is running fine, but having given it a once over it looks pretty good