Copper head gasket fitment for the uninitiated

[flipper]

I've seen mention of others on here using copper head gaskets, so hoping for some advice.

I'm looking to fit an oversize copper head gasket on my 600 due to having some issues running the standard Yamaha gasket with a 1mm oversize bore.

Whilst the standard gasket is designed to be torqued once at assembly, does using a copper gasket mean that I should re-torque it after running the engine through a heat cycle?

Also, how much copper gasket spray are people using, and how long should it cure, before fitting the gasket?

Thanks, Peter

[scottieh]

I've seen mention of others on here using copper head gaskets, so hoping for some advice.

I'm looking to fit an oversize copper head gasket on my 600 due to having some issues running the standard Yamaha gasket with a 1mm oversize bore.

Whilst the standard gasket is designed to be torqued once at assembly, does using a copper gasket mean that I should re-torque it after running the engine through a heat cycle?

Also, how much copper gasket spray are people using, and how long should it cure, before fitting the gasket?

Thanks, Peter

Hey Pete, I've installed three copper gaskets made by board member u/xtrider that he waterjet cut based on the OEM shape. Previous to installation I annealed the gasket by holding it over a propane flame until it turned a cherry red and then quenched it in cold water. I did not used any copper gasket spray. As of today, at around 1,000 miles, I have not seen any leaks developing around the head gasket and I have not checked my torque settings since installation. Hope this helps!

[flipper]

Thanks for the info Scottieh. It's good to hear that there isn't a need for re-torqueing.

I thought the annealing process was only needed when the gasket was reused, as a brand new gasket should still be very pliable - did you notice a difference after the heat treatment?

Is there a downside to using a copper spray on the gasket (apart from the obvious extra cleaning required if rebuilt)?

Cheers,
Peter

[Eric66]

You can buy cometic 98mm gaskets from the states.
Regards Eric

[scottieh]

Thanks for the info Scottieh. It's good to hear that there isn't a need for re-torqueing.

I thought the annealing process was only needed when the gasket was reused, as a brand new gasket should still be very pliable - did you notice a difference after the heat treatment?

Is there a downside to using a copper spray on the gasket (apart from the obvious extra cleaning required if rebuilt)?

Cheers,
Peter

Yes I did notice a difference in malleability between unannealed and annealed. Keep in mind this was a gasket made by a board member cut from a sheet of copper and so it may not have gone through the same prep stages as a commercially available gasket.

[flipper]

You can buy cometic 98mm gaskets from the states.
Regards Eric

Thanks Eric - I managed to get a 96mm copper one from an eBay seller - it seems to line up nicely on the barrel, so I'll use that for now. I just needed to know what the correct process for installing it was.

[xtrider]

The annealing is a good idea no matter where the copper is from , it'll just help make it seal better . Mine were pure copper sheet and I have 2 in XT's with no leaks . I did re torque mine after about 500 miles but the bolts didn't really move , is nice to do it just in case .



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