TDM 900 engine with TRX head

[Rich]

Has anyone used a TRX head on a TDM 900 engine in a TRX frame? Is it a straight fit apart from the centre engine mounts, oil tank fitting and possible chain alignment issues? Basically I want to keep the carbs, std ignition etc and as mine will need rods, rebore, crank checking/grind (I've just bought a hopefully good head!) so it may be better to fit the head onto a TDM and have what may be lower oil consumption and better fed crank.

[Killerwhale]

Has anyone used a TRX head on a TDM 900 engine in a TRX frame? Is it a straight fit apart from the centre engine mounts, oil tank fitting and possible chain alignment issues? Basically I want to keep the carbs, std ignition etc and as mine will need rods, rebore, crank checking/grind (I've just bought a hopefully good head!) so it may be better to fit the head onto a TDM and have what may be lower oil consumption and better fed crank.

Yes

[alextrx850]

This is a good topic,..I've often thought that Yamaha would have developed the TDM 900 and then gone the same as the TDM850 and made the TRX900. (Maybe the previous influences weren't there)..
Is the use of the TRX head only to have the frame to head support lug ?
And are the oil pumps in the TDM900 better than the TRX850 ones ?
Are we just better off just buying a KTM 1290 super duke and letting the people with the diplomas do the designing ?
Maybe.

[Rich]

Hi Alex'
Is the use of the TRX head only to have the frame to head support lug ?
that and to run carbs, don't really like EFI as would need the loom, ECU maybe clocks etc to controls it and to my thinking less is better, if the TDM head would go better with just a lug welded on (as Coxylad), but ditch the EFI that may be the way to go.

And are the oil pumps in the TDM900 better than the TRX850 ones ?
Don't know, but from all I've read recently they seem to be or there is a better feed to the crank, it may be that it's a 10 yr old engine as opposed to a 20 year old one and materials and QC have improved in that time.

Are we just better off just buying a KTM 1290 super duke and letting the people with the diplomas do the designing ? Probably, but I like playing in the garage so most of the fun would be lost to me.

Hi Killerwhale,
I've seen your bike - very nice it looks too. Apart from the flatslides, pipes and ECU, any other mods to the engine to get it to fit?

[coxylaad]

I have the full 900 setup from the TDM900. including all electrics, clocks, fuel pump etc, and funnily enough I have just last night been out on a TRX with a 900 engine with the 850 head (and FCR's) so I am probably in the unique position to give a proper balanced appraisal.

They are both great, but different.

The Specs are as follows:
900 FI:
Full TDM 900 engine, in stock form.
Big bore exhaust
Airbox removed and replaced with a shared filter pod.
Power Commander

900 FCR:
TDM 900 block and barrels, mated to a flowed 850 head.
41mm FCR carbs
Akropovic full exhaust system
Standard airbox

We have just picked up the 900 hybrid bike, that's why I was testing it last night. Power wise there is not a lot in it. I would say the FCR bike is a little stronger, but it wouldnt pull bike lengths on the straights at Cadwell (our test track )
I was very impressed with the civility of the FCR's. it was the first time I have rode a bike with FCRs, and it behaved impeccably. It looks like its running a little rich, and the bike itself needs a little bit of work but its a good setup. the 6 speed box is really big improvement, and well worth the hassle. Then there is the absence of oil consumption. I have done about half a dozen track sessions at teesside and a full day at cadwell on mine and havent had to put any oil in at all.

If I had to do mine again, I would probably still go down the full fuel injection route, as I have had nothing but good things to say about it. It pulls like a train, behaves like a bike that has just come out of the show room, and has a really hard clean edge about it in both the noise it makes and the throttle response.

The hybrid bike itself has renthal bars which were quite honestly horrible and will be getting removed asap, 6 pot calipers which, to be honest I preferred my blue spots, and the clutch was slipping every so slightly. The throttle response was not as clean as the injected bike, but if you hadnt rode them back to back you would never ever notice. Also the tyres were completely shot so that affected how the bike wanted to turn. We just picked it up at the weekend so with a little bit work it will be a good un!
sorry I wandered off topic a little!

[marcimark]

Are we just better off just buying a KTM 1290 super duke and letting the people with the diplomas do the designing ?
Maybe.

I would ride a 990 Super Duke if I had longer legs

[coxylaad]

"Are we just better off just buying a KTM 1290 super duke and letting the people with the diplomas do the designing ?
Maybe."

Maybe if you had buckets of spare cash to throw about. I actually prefer bikes of a certain power output. Above a threshold things start to get very serious.

[Rich]

Thanks Coxylaad, that's just the sort of thing I was hoping for. To me the TDM/TRX head looks the way to go and finding a good TDM is easier by the looks of it.
Could you let me know if it uses the TRX ECU or the TDM one?

Don't worry about going off topic - I do all the time I found the Tokico 6 pots worked better and were less wooden with -2 hose, but certainly preferred 4 pot Nissins for overall feel. It came with newish ProLites and blue spots so I'll be leaving those on.

[coxylaad]

The 900 with the 850 head runs all the 850 electronics.

If you do go the fuel injection route then you will have about 80 joints to solder as relay part of the loom needs extending.

Either route is going to be a lot of fun

[Rich]

Many thanks - just need a good TDM engine now

[phil108]

There is 3 for sale on flebay......

[alextrx850]

"Are we just better off just buying a KTM 1290 super duke and letting the people with the diplomas do the designing ?
Maybe."

Maybe if you had buckets of spare cash to throw about. I actually prefer bikes of a certain power output. Above a threshold things start to get very serious.

Thanks Coxylaad, said well..

Guessing if the TDM 900 motor was used with the fuel injection in place, the TDM900 loom would obviously be used .
Interesting thought to sell a working motor with a set of FCRs in place ,..would be enough to placate a Tdm pump.

[Rich]

There is 3 for sale on flebay

4 , I did mail the one at Congleton to ask if I could hear it running but he has taken it out of the frame last weekend. I'm making the top yoke at the moment and going on hols so will probably start looking properly next month.