Hey guys - Couple of questions on head gaskets and to possibly rootcause a leak.
Combo: 2000 CR500 / '89 Motor / '86 style HF-1 head / 1.5mm Over
Running a Cometic 85-88 (thicker) head gasket to get compression down with HF-1 head and pump gas. Started up the bike and I'm leaking out of the front of the head. Actually most of the coolant is bubbling up through the stud/nuts on at least 3 of the forward studs. It was hard to tell if the leak was actually coming from the gasket area or just dripping down from the studs. I did not use gasket sealer and did not check head for flatness (although head was re-installed as-is and didn't leak before)
I re-checked torque and they were good. Gave them about an extra ¼ turn. This improved the seal but still seeing little bubbles coming up the forward couple of studs.
I’ve ordered Honda gasket P/N 12254-ML3-881 which is the 3 layer for ‘85-‘88. However I’m not sure I can use this with a 90.5mm bore – Can anyone confirm? Without removing the gasket from the package it looks like the ID is about 90.2mm.
If I can’t run this OEM gasket due to my bore size, can anyone recommend a good one? With or without sealer?
I have not taken it back apart yet to check, but I suppose if the head measures more than 0.002” out for flatness I’ll need to work it in with some light sand paper on a granite plate?
Thanks,
Scott
Head Gasket Questions - OEM with Overbore & Coolant Leak
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- Joined: November 21st, 2012, 7:59 am
- Location: Farmington Hills, MI
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- Posts: 4
- Joined: November 21st, 2012, 7:59 am
- Location: Farmington Hills, MI
Thanks for the info. But I'd rather not introduce a whole lot of machining here or have to buy a new head just yet if you meant you have a head for an offer.
Seems this thing should be sealing and I've either got a bad Cometic gasket or a warped head. I'd still like to know what is the largest bore you can run with an OEM head gasket.
Thanks,
Scott
Seems this thing should be sealing and I've either got a bad Cometic gasket or a warped head. I'd still like to know what is the largest bore you can run with an OEM head gasket.
Thanks,
Scott
2000 CR500