Yamaha TRX850 Enthusiasts Forum

Evening all

I will be changing my old buggered block for a decent second hand one very soon, I have already checked its vital signs and all dimensions are spot on.

I was just wondering if anyone can suggest any parts that are worth changing while im there, obviously I will being doing piston rings and gaskets etc, but im sure there are other bits to do also. The engine has only done 14-15,000 miles from new.

Cheers muchly.

As it`s easy to get out while you are doing the engine work, check the cam chain and tensioner / blades too. TRX`s seem to be bug*ers for stretching cam chains within quite short mileages.
I think if my addled memory serves me correctly, another member posted somewhere the new `unstretched` length of a cam chain here on the forum.
I think the number of links and type are quoted in the downloads section but not certain if an overall length is given.
Easy enough to measure a new one, just use a piece of string laid along it as the cam chain is a hyvo / endless type.

http://www.wemoto.com/bikes/Yamaha/TRX_ ... Chain_DID/

You `may` find them cheaper if they are other makes but DID is a good quality chain.

You may find it doesn't need rings but as Mince has said, while you've got it stripped down that much you may as well check the cam chain / tensioner.

Other than that, you could check for any slop on the crank bearings and damage to the cams. Valve clearances are a given.

I personally would also have a look at the oil tank - you'll be amazed how much sludge builds up in there.

That should keep you busy

Thanks men for the info, most helpful. Thanks heaps.