Dang it,
Forgot to mention.. Use gloves and acetone to clean the mating surfaces. Aluminium and copper are porous and will retain that degreasing stuff. Acetone is some deadly shit, so use carefully.
Ciao, Nick Alaniz, 2002 Ducati ST4$, Sacramento, CaL.
----- Original Message -----
From: "Nick Alaniz" <nicktoh@comcast.net>
To: "st2 owners" <st2_owners@yahoogroups.com>
Sent: Sunday, February 13, 2011 2:12:17 AM
Subject: Re: [DucatiST] Leaking Copper Head Gaskets
Colin,
Finish the copper gaskets kinda rough, 220 grit. Make the finish round, think micro hedgerows for the oil to travel over. I know, sounds weird, but it makes for a better barrier with the copper spray. I like to use a stainless steel "toothbrush" to roughen up the cases and the bottom of the cylinders too. Brush round with the circular metal.
Other wise torque them +10-15 lb/ft. It'll squash em good, and it might stop the leaks.
Good luck, and good hunting.
Nick Alaniz, 2002 Ducati ST4$, Sacramento, CaL.
----- Original Message -----
From: "golgrin" <ecol@paradise.net.nz>
To: "st2 owners" <st2_owners@yahoogroups.com>
Sent: Saturday, February 12, 2011 5:15:31 PM
Subject: [DucatiST] Leaking Copper Head Gaskets
02 ST4S 25Kmiles
I cannot get these gaskets to seal coolant completely.
Its not gushing out.......a 2 hour hard ride the other day used about 1/2 cup of coolant.
Coolant leaking out of vert head just under exhaust header.
Horizontal out of intake side and slight seepage at base gasket.
No sign of any getting into oil.
I had taken heads off to lap valves etc.No problems with original gaskets...no leaks.
After the valve work I flattened head surfaces on glass with lapping compound and reassembled with Cometic copper base and head gaskets.
I had annealed and then removed oxidation on the gaskets prior to using.
Surfaces were cleaned with engine degreasing spray then dried.
2 coats Permetex Copper Spray on the gaskets and reassembly very carefully to the book with the 3 stage tightening and the retightening after 1st heat cycle then after about 100 km.
After 2-300km more I tried retorquing again....a tiny amount of movement if any altho pretty hard to tell if they actually tightened.
Whats going on here?
What am I missing?
Heads off for 3rd time in under 500km is no joke eh?
Thanks.
Colin.
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