Yamaha TRX850 Enthusiasts Forum

I am runninng a higher compresssion ratio and was wondering about using a copper head gasket.

Does the XTZ750 have a copper gasket and if so could you open up the bores a bit to fit the TRX bores? 2.5mm bigger on TRX

One moment please caller.

Cobba is getting one.made up at the moment and will be along
shortly

Or these guys might be worth a phone call.
I think they might not be too far from you.
http://www.stephensgaskets.co.uk/produc ... ad-gaskets

Might not be any good to you in the UK, but.......

http://www.obrien-aluminium.com.au/gasket_1.html

Just had one made up at 0.9mm thickness which is 0.1 or 0.004 thinner than the std OEM yamaha gasket. The clearance maths where done on my motor rebuild and if I went any thinner I would start to sacrifice the valve/piston clearance just incase I hit a neutral and the motor has a big rev and the valves waggle n float about.
For around the same price as an OEM its money well spent as you will get a better compression seal than a composite and its reusable.
I'll have few on hand shortly to go with the 12:1 Arias 878 pistons when they arrive next week.
I'll get him to produce a couple of std bore 89.5mm ones too so they can be used on a std motor or bored in conjunction with the barrels if going for oversize pistons.

I've attached a photo on the previous msg..

Nice work, what will it cost?

$82
Which is better than $95 for an OEM from Yamaha.
Most places will make them to various thickness to suit your needs.
I'm sure the price in old blighty would be much the same Simon.

thats a good price, I will have one at that PM me