Changes through the years?

[pbear62]

A very minor change - '96 models had "YAMAHA" printed on tacho face - later
models had the tuning fork logo.

[Mincehead]

I wouldn`t know, my 96 never had the stock clocks, nor fairing and bracketry adding extra weight either.

[dandywarhol]

Earlier ones, pre '97 had TRX on the fairing, later had it on the tail.

[Killerwhale]

Other way around mate, i got the top one and it´s a -98

[dandywarhol]

Ah, ok, mine's an August '96 with original paintwork and TRX on the fairing - does that mean it's the first of the newer design??

[Killerwhale]

Ah, ok, mine's an August '96 with original paintwork and TRX on the fairing - does that mean it's the first of the newer design??

Perhaps, or it looks different in different countrys.
The below pic is a Swedish -96 i think...looks just like "hansJ" ´s bike....

[dandywarhol]

Now I'm confused - I trawled the interweb and found original schemes - 1995 blue with TRX on the fairing and the pseudo race plate on the tail but also a '98 red/black in the same design, whereas the green seems to be a late 90s scheme with TRX on the seat! The Japanese home market ones seem to have no TRX on the fairing....................

Can anyone shed some light??

[M.V.]

Ummm...the post 96 ones didn't hemorrhage oil

Ah... mine must be a 95 model!

[dfh]

Not withstanding the colour scheme variations...( my 96 in red has TRX on tailpiece) the only mechanical changes I know of for a fact is the change of inlet valves '97 build and after. I have part numbers, both 95-96 & 97 plus, on file somewhere from when I reconditioned my head 5 years ago. The original inlets stretched, increasing oil consumption dramatically & taking up the clearances to zero. Interestingly Yamaha Oz claimed no changes to the valves & thus only one part number for the inlets, but when I ordered specifically by the new 97 & later part numbers ( kindly provided by HansJ in Sweden) Yamaha Oz supplied the inlet valves with those numbers.

I have also have seen it noted that there were changes to first & second gear but I have not researched those parts...

[pbear62]

According to a '96 copy of Australian Motorcycle News I have, the Australian models had
"the same final gearing as the European models - 2 teeth smaller on the rear sprocket
than the Japanese models" Is this true?

Also, on the original '96 sales brochure from Yamaha it mentions that they are fitted with
flatslide carbs! Some gumby bean-counter must have put a stop to this before production

In Australia, I'm fairly certain the only ones that had TRX on the fairing were the Red/black
fade model & the blue '99 model.

[Mincehead]

Not withstanding the colour scheme variations...( my 96 in red has TRX on tailpiece) the only mechanical changes I know of for a fact is the change of inlet valves '97 build and after. I have part numbers, both 95-96 & 97 plus, on file somewhere from when I reconditioned my head 5 years ago. The original inlets stretched, increasing oil consumption dramatically & taking up the clearances to zero. Interestingly Yamaha Oz claimed no changes to the valves & thus only one part number for the inlets, but when I ordered specifically by the new 97 & later part numbers ( kindly provided by HansJ in Sweden) Yamaha Oz supplied the inlet valves with those numbers.

I have also have seen it noted that there were changes to first & second gear but I have not researched those parts...

This valve `stretch` has been discussed many times over on this forum and I can assure you that vlaves DO NOT start out stretching as such.
They in fact pocket themselves into the seats first thereby giving the same issues with lack of clearance and then accelerated burning of valve head seating face and valve seat surfaces.
Of course they CAN reach the point whereby they themselves are compromised by the poor seating and it`s often their undercut stem behind the head (to aid in gas flow) where if any stretch / movement is going to occur could happen. Distortion is commonly seen, heads not square to the stem etc.
Of course once the lapped seal between valve head and seat is compromised power drops off, heat builds into the head, wear on cam journals and associated surfaces accelerates and it`s the kiss of death to the motor if it`s not picked up on and dealt with.
Excessive heat build up destroys the flexibility of the viton valve stem oil seals and the oil usage increases accordingly.
Can you turn up those valve part numbers, I can have a word with a Yamaha storeman I know very well to check out the authenticity of the need for part number changes in relation to the `toffey valve` claims?
Remember many manufacturers modify numbers as the range increases and some parts overlap models or are generic.

[dandywarhol]

To my knowledge, there was never a change to the valves on the same head TDM which came into production in 1996. Can we assume then that '96 was the year the valves were changed?

[Mincehead]

Did early TDM`s suffer from the valve clearances closing up too A?

[dandywarhol]

Nope - that's why I'm wondering if the change was '96

[Mincehead]

Well my 96`er ticks away happily, the valve stem oil seals are tired and I suspect the bores of being glazed but my valve clearances are most certainly still there, my 88 bhp plus at the wheel (dyno last year) gives testament to that.
IF it existed it must have been VERY early in the production run.