Piston change on a Yamaha Xt 600 -88

[WebGringo]

Having a question on above mentioned project. Found out that the piston on the bike is starting to wear, and rattles a bit so might be a good idea to get it changed and rebored in the near future.

After looking around i found that the pricing for a original or high compression piston do not differ to much.

Question is, can the old machine handle it ?

The xt engine is known to be reliable, how much will this change ?

Wear and tear ?

Bearings to be changed ?

Grateful for whatever input u might have on this

[NOMADAK]

I had a 1990 XT600. I put 25,000 miles on it before selling it. It was huffing a bit of oil/smoke out the tailpipe but would still pull over 100mph.

The motor is claw hammer reliable as a design.

How many miles do you have on the machine? How long have you owned it? How has it been maintained?

[450X22]

Because the carb/cam/exhaust is so mild on that bike I recommend staying will the stock piston/rings set up. Rejet, open air box, add upgraded exhaust, and upgrade the fork springs. This bike doesn't like anymore than this.

[WebGringo]

Had the bike for a year, and besides the noise its running like a champ, and always fireing up on first or second kick.

Got 35 000 km on the bike, been rattling a bit since 25 000 km but getting worse.

Well maintained, valve clearance checked twice a year, oil changed 2 till 3 times a year.

Been ridden by an older man as a commuter before i got it.

Is a supertrapp with modded airbox and rejetted already.

[NOMADAK]

There are a couple of guys up here who ice race older tt600's and have high compression pistons/White brothers cam/pipe combos. The bikes were no more or less reliable than they were when new. They were much stronger running though. I haven't seen them for a few years now. I am pretty sure they were '86 /'87 models.

I had looked on the White Brothers website for such a kit when I had my Xt600 and they were no longer available. The White brothers have sold to another group now, so that will most likely be a dead end anyway.

I say go for it. Are you going to rebuild yourself? You need a machine shop to mic out the cylinder for you before you buy any piston. You need to see how much wear the cylinder has on it right now. Check at the top, middle and bottom to see if the cylinder is square. Then from those readings you will know how worn the cylinder is and be able to determine exactly what sized piston you need for the motor's tolerances. At the very least you need to re-hone the cylinder. You don't want to slap a new piston in an old worn out bore.

[WebGringo]

Got a haynes manual, and high hopes, so yea, planing to do it myself.

How hard can it be on an old air cooled thumper ?

Plan to take the cylinder of and leave it to a machine shop.

Ordering parts from the spec i get there.

Got some info from a yamaha dealer that said that most XTs have a wear in the top of the cylinder, just a question of how much.

Change of cam would be cool, but expensive as well.

Will, me knowing, cost at least as much as the piston and gaskets put together.

And that to be run on a tight student budget. =o/-

Heard something about a top end rebuild, how much is to be done there ?

Checking tolerances and that all valves are ok ?