Which sealant do you use?

Fifth times a charm...I hope.
Have a hellva time sealing the cylinder cover without a gasket. It seeps oil when hot at different points. Never at the same spot after resealing the cover. Cover is not warped.
I've tried these four products:

• Permatex Ultra Copper
• Napa/Permatex Form-a-gasket Aviation
• Yamabond
• Permatex Form-a-gasket #1

What product has worked for you guys?

What is a cylinder cover? Are we talking about valve covers or similar on a four stroke? There is some spray that comes out pink to purple from an a spray can. It can be sprayed into the cap and put on as a liquid. High tack perhaps. used it up years ago. Norton mechanic liked that.

It's called a "top cylinder cover" on a four stroke 510. Valve cover is the cover used for adjusting the valves. I suppose many call it a rocker cover.
No gasket are used nor required for assembly.

Thanks Dirtdame. I used the UltraCopper which is the same as UltraBlack but with a higher temp rating. Maybe it's my technique that's failing me.

If it is a sealer only joint I use "right stuff", made I believe by permatex. Tough to get apart again though. Prep before with brakecleaner or acetone, one drop of oil or coolant and no seal.

I'm still not clear which part is needing sealant. Is it what most of us would call the valve cover or something else? What bike are we working on? I know we're in the vintage side but still helpful for us numbskulls to know what you're talking about, lol.

Honda has some really good stuff and it comes in two different styles. One is softer than the other when dry. I used this Honda brand on a two stroke cylinder instead of a gasket and was impressed with it.

ya need a pic?:smirk:...look at the first post. It's call a "cylinder top cover" per the service manual.

HuskyDude- Gasgcinch was my first choice but I can't find it around these parts.

Yes, I do. I don't know the vintage parts/lingo/quirks. If you saw service/parts manuals I deal with for a living you'd understand, maybe.

I was waiting for the o-ring to arrive from MotoXotica. Brown Box truck arrived a few hours ago and I gave Yamabond another try. It's all buttoned up and I'll start the 510 tomorrow.

We'll see if I sealed it this time. Don't know if I can stand another round off this!

I re-read your post and if I understand it correct you are trying to seal a gasketless mating surfaces? If so and especially if they are dissimiliar material or just different sizes-expansion/contraction rates I would suggest this. Try a anerobic sealer from Permatex, I believe the number is 518. It flexes with flanges for example to provide a "o-ring" type of seal. Used alot when mating two alum. housings together in the automotive industry, also alum. to steel. Red jelly looking stuff that only dries in absence of air-anerobic. I use it instead of a gasket on my clutch covers and no leaks. I can verify that part number tomm. at the shop if you wish. Scott

Scott-
Yes, that's correct. Two machined flat aluminum surfaces together.
Tolerance has to be in the thousands as the rocker arms reside in the top part and adjustment to valve lash has to be taken into consideration, hence no gasket.

I'll see what the results are with this round. I did install a new o-ring this time to the camshaft cover. The previous one was used in the last two attempts.

I would be interested in the Permatex item number.
Thanks

I have had great luck with it, Permatex part number is 51813, thats a pretty big tube and I'm sure you can buy a smaller tube. Above part number is around $25. I think you will be satisfied with the results. Easy clean up as it doesnt dry away from the actual joint. Scott