Topic: 1979 CB650

[scott jones]

I put the engine back together & I have oil running out of the cylinder head. It looks like it's coming from the head cover running down by #1 spark plug. I put 6 rubber plugs in the head for the head bolts to prevent leakage but I think 1 of them is leaking. Should I have put some sealant on those plugs? Please advise. Thanks! Scott.

[fizzlebottom]

One suggestion that I've seen multiple times is to use a layer of Hondabond or Permatex liquid gasket sealant between each puck and the cylinder head. The thickness of the sealant should depend on whether or not you got genuine pucks. I've seen accounts of folks who got really thin aftermarket pucks that caused leaks.

[scott jones]

Ok I thought the aftermarket pucks were the same size as the OE ones but I'll check it again. Thanks for the tip. Scott.

[scott jones]

I noticed when I looked at the original plugs they had a little dome on one side of them. The other side was flat & they seem to fit the hole in the head better so I plan to reuse them because they also appear to be thicker than the aftermarket ones I installed. My question is do the little domes go upwards toward the cover or does it matter? Thanks. Scott. I'm sorry for these questions but the engine was apart when I got the bike.

[fizzlebottom]

Don't reuse the original pucks. Even if they are undamaged and still pliable, they are old as #$%* and will not have anywhere near the life span that you want. You can use aftermarket pucks, but need to use some of the non-hardening gasket sealant to help them along.

The originals are domed because they are slightly stretched from years of hot oil sloshing against them.

[scott jones]

Oh I see. I didn't realize that. Thanks for the tip.