Yz Head Gaskets On A Tri Z

[Semo Tri Z]

Does a 88-94 head gasket off a YZ 250 work on a TRI Z??????????? I hear that the 85 YZ gasket will work and increase compression but what other years will work also.

[Derrick Adams]

Pretty sure the all the newer YZ head gaskets are O-rings. I know my 87 is. I disassembled the stock Tri-Z gasket and removed one of the 3 pieces.

There are 3 sections, one thick one and 2 thin ones. Each thin one you remove should raise your cylinder pressure by about 20-30 lbs.

[twgranger]

Pretty sure the all the newer YZ head gaskets are O-rings. I know my 87 is. I disassembled the stock Tri-Z gasket and removed one of the 3 pieces.

There are 3 sections, one thick one and 2 thin ones. Each thin one you remove should raise your cylinder pressure by about 20-30 lbs.
The gasket still works if you do that? No leaking or heating problems?

[Semo Tri Z]

So have you had any leaking or heating issiues with the modified head gasket? And before i try this please explain how they come apart. I don't remember exactly how that head gasket went together. Is it easy to get apart?

[Derrick Adams]

No problems to speak of. I should note that I did this to bring up my compression to normal range. When I installed the YZ top-end my compression was only at 150lb.

This is an old 250R trick from way back. The gasket layers are held together with 2 rivets. They simply pop apart with a small screw driver. I would advise to check your compression before hand, and not exceed 200lbs.

I have mine between 175 and 180lbs.

[Semo Tri Z]

I checked my compression today and it is about 190psi, so i probably be better off leaving it alone huh. I am just looking for every little bit of extra horsepower i can get without spending a bunch more money. Any other tricks you can help with?

[Derrick Adams]

Stock 250R carb!!!!

[wolfspider]

yz250 85 head gasket fits tri z 85 head, plus if you get yz250 85 gasket set about 80 per cent of the gaskets fit tri z.
cheap power up for triz is any air box mod as the tri z struggles to breath through its complicated air box, plus pipe and rejet. :w00t: