Another crank gone!!

[misterdimwiddy]

Not good news.

All three main bearings are totally shot.

Looks like wear due to high mileage but doubt it's repairable economically.

Now what do I do once I have composed myself???

Buy another TRX and break mine?? Might be the best way fwd.

Anyone got a spare crank that just needs a big end regrind??

Groan..................

[dixonj]

Bad news, so what parts do you need ?.

[misterdimwiddy]

Just phoned for a price on a new Yamaha crank for a larf.

£1371.78 + 10off shells at £9 each.

So that's not the answer to my troubles then!!

[zednine]

Im afraid that by the time youve rebuilt the motor with crank , shells , gaskets , piston rings , shims etc youll be looking at the thick end of 600 quid ......... you can pick a Trx up for a grand and sell the spares and if you get lucky break even or at least reduce the costs and the hassle

Ive had to do it twice and its the only way ynless you are lucky enough to come across an engine.

Chris

[dixonj]

Im afraid that by the time youve rebuilt the motor with crank , shells , gaskets , piston rings , shims etc youll be looking at the thick end of 600 quid ......... you can pick a Trx up for a grand and sell the spares and if you get lucky break even or at least reduce the costs and the hassle

Ive had to do it twice and its the only way ynless you are lucky enough to come across an engine.

Chris

Might have to sell Phil my spare motor

[Snod Blatter]

Sorry that I can't help but I wonder what you mean by the mains being shot? Do you mean the crank itself is worn or warped or what? How many miles do you think the engine had done?

I'm just interested is all..

[misterdimwiddy]

I think that my motor has done many miles but will never know how many.

The main bearing journals are all deeply grooved, more so than the big ends. Main bearing shells are all showing a coppery colour in places which means the white metal surface has worn away.

The crank is not bent but repair is not an option I think.

Adding FCR's is what finally made it fail but it was fast while it lasted.

Hope you don't have the same experience as me!

[Snod Blatter]

Oh dear God.. People say these engines are tough but they're not really. I ended up taking mine to Germany (1700 miles in a week!) on worn oil which it drank so fast that it was out of the sight glass on the first day with the top end tapping. Back then I assumed it was all needle and ball bearings (like the Honda motor I've rebuilt) but now I'm very concerned about what might've been done. I hardly went above 4K the whole week aware of the old oil (although I did keep it topped up!) so hopefully it's not too bad, but

As a project idea, would a 360 TDM crank and cams fit? It's supposed to be a much gruntier setup..

[Killerwhale]

Oh dear God.. People say these engines are tough but they're not really. I ended up taking mine to Germany (1700 miles in a week!) on worn oil which it drank so fast that it was out of the sight glass on the first day with the top end tapping. Back then I assumed it was all needle and ball bearings (like the Honda motor I've rebuilt) but now I'm very concerned about what might've been done. I hardly went above 4K the whole week aware of the old oil (although I did keep it topped up!) so hopefully it's not too bad, but

As a project idea, would a 360 TDM crank and cams fit? It's supposed to be a much gruntier setup..

You never have bad oil in a TRX do ya? The extreme topping up on a TRX makes for alway´s fresch oil!

[misterdimwiddy]

Oh dear God.. People say these engines are tough but they're not really. I ended up taking mine to Germany (1700 miles in a week!) on worn oil which it drank so fast that it was out of the sight glass on the first day with the top end tapping. Back then I assumed it was all needle and ball bearings (like the Honda motor I've rebuilt) but now I'm very concerned about what might've been done. I hardly went above 4K the whole week aware of the old oil (although I did keep it topped up!) so hopefully it's not too bad, but

As a project idea, would a 360 TDM crank and cams fit? It's supposed to be a much gruntier setup..

I would not say that they are weak motors at all; the opposite infact.

Just need consistent maintenance and a close eye on oil level.

There are plenty of examples on the forum of very high mileage TRX's out there.

My error has been adding 20hp to what is an old high mileage motor, thrashing it on the track and it has understandably said enoughs enough.

[Killerwhale]

Oh dear God.. People say these engines are tough but they're not really. I ended up taking mine to Germany (1700 miles in a week!) on worn oil which it drank so fast that it was out of the sight glass on the first day with the top end tapping. Back then I assumed it was all needle and ball bearings (like the Honda motor I've rebuilt) but now I'm very concerned about what might've been done. I hardly went above 4K the whole week aware of the old oil (although I did keep it topped up!) so hopefully it's not too bad, but

As a project idea, would a 360 TDM crank and cams fit? It's supposed to be a much gruntier setup..

I would not say that they are weak motors at all; the opposite infact.

Just need consistent maintenance and a close eye on oil level.

There are plenty of examples on the forum of very high mileage TRX's out there.

My error has been adding 20hp to what is an old high mileage motor, thrashing it on the track and it has understandably said enoughs enough.

Correct, they bored the XTZ to 850 and made it 270 for paris dakar and it really performed way back. Guess the trix could do with a small rebore and nikasil linings. My TDX now use NO oil at all, and if 900 oilpumps fit you should all do a change....they are wayyy better pushing oil thru system!

[dixonj]

Oh dear God.. People say these engines are tough but they're not really. I ended up taking mine to Germany (1700 miles in a week!) on worn oil which it drank so fast that it was out of the sight glass on the first day with the top end tapping. Back then I assumed it was all needle and ball bearings (like the Honda motor I've rebuilt) but now I'm very concerned about what might've been done. I hardly went above 4K the whole week aware of the old oil (although I did keep it topped up!) so hopefully it's not too bad, but

As a project idea, would a 360 TDM crank and cams fit? It's supposed to be a much gruntier setup..

I would not say that they are weak motors at all; the opposite infact.

Just need consistent maintenance and a close eye on oil level.

There are plenty of examples on the forum of very high mileage TRX's out there.

My error has been adding 20hp to what is an old high mileage motor, thrashing it on the track and it has understandably said enoughs enough.

Correct, they bored the XTZ to 850 and made it 270 for paris dakar and it really performed way back. Guess the trix could do with a small rebore and nikasil linings. My TDX now use NO oil at all, and if 900 oilpumps fit you should all do a change....they are wayyy better pushing oil thru system!

Any evidence to back this up about the 900 oil pump. If so it would be a great upgrade for people who run modded motors.

[misterdimwiddy]

I wonder whether the TDM900 runs at higher oil pressure then?

Maybe you could achieve this by altering the pressure relief valve in the sump of the TRX (p2-19 and 2-20 in the online manual). Shimming the spring or changing it may be possible but s'pose you would need a gauge on the system to see the effect of any change (+ temperature/viscosity affects on pressure to complicate things).

I recall doing something like this on my old RSC998 CB900F.

Looking at the diagrams it is not clear to me which of the two pumps the relief valve affects; you would think it would be pump #2 for motor lubrication; why regulate the pressure for the tank return?

Also noted that the gallery bolt in the head appears to be on the main pressure circuit (p2-22 fig A) , not simply gravity fed. Mine always trickled from here (low pressure?) when I thought it should have given me a good drenching when removed.

Doubt there will be many 900 pumps around especially if we are all looking for them.

[Kenny]

Id like to know if the TDM900 suffers the same bearing failures and if not whats the reason for this. Maybe something in the pressure relief valve or the oil pump pumps more oil and at a higher pressure.

[Killerwhale]

I wonder whether the TDM900 runs at higher oil pressure then?

Maybe you could achieve this by altering the pressure relief valve in the sump of the TRX (p2-19 and 2-20 in the online manual). Shimming the spring or changing it may be possible but s'pose you would need a gauge on the system to see the effect of any change (+ temperature/viscosity affects on pressure to complicate things).

I recall doing something like this on my old RSC998 CB900F.

Looking at the diagrams it is not clear to me which of the two pumps the relief valve affects; you would think it would be pump #2 for motor lubrication; why regulate the pressure for the tank return?

Also noted that the gallery bolt in the head appears to be on the main pressure circuit (p2-22 fig A) , not simply gravity fed. Mine always trickled from here (low pressure?) when I thought it should have given me a good drenching when removed.

Doubt there will be many 900 pumps around especially if we are all looking for them.

It does, same amount (and i use TRX tank and pan) and the glass i over full at pressure. Those metal pumps really push way better!