Yamaha TRX850 Enthusiasts Forum

Has anyone on the forum ever used a flywheel from a 96 TDM in a TRX 850. The yamaha part numbers are identical apart from the first 3 model numbers. A 96 rotor assembly is listed as 4NX-81450-00. The 96 TDM part is 4TX-81450-00.
I am restoring my 96 trx engine and during the engine being stripped, the rotor assembly (flywheel) rusted badly and I wanted to replace it. I bought a cheap TDM flywheel off E-bay and it looks identical to my old TRX unit apart from three small drillings on the TDM unit.
Thanks in advance for any advice given.

Drillings are for balancing I suppose.
With both engines being 270 degree cranks, the flywheels should be interchangable. Although the different codes in partnumbers make me less sure about it. After a visual comparison if they are the same I would give it a try.

4NX simply says it's early TRX. Europeans are 4UN. 4TX is the name of 2nd gen TDM...

jpe70 wrote:4NX simply says it's early TRX. Europeans are 4UN. 4TX is the name of 2nd gen TDM...

I know, but the different partnumber might suggest it is specifically made for that model.
In the partlist of the TRX are also partnumbers with the codes of the YZF750 (4FM), FZR600 (3HE), etc.
So you can be sure the parts are exactly the same. Why would they change the partnumber, even only the first 3 digits regarding the model code, and not the part itself?

It wouldn't surprise me if they are different weights, do you have a decent set of scales to hand?