Valve cover gasket mating surfaces

Hey all,

I'm replacing the valve cover on my KZ650, and am in the process of the painstaking task of carefully scraping the old gasket off with a razor blade. May have just barely scraped into the aluminum here and there :blush: but I don't think it's anything that would compromise the seal. There is some seriously stubborn residue on this thing!

The parts that I've worked on are smooth to the touch, but there's still some faint traces of red from the gasket here and there. Must this be removed, and if so, does anyone have any suggestions as to how? I'm hesitant to get any more aggressive with the razor, as I'm afraid I'll end up doing more harm than good.

[Edit: picture didn't work the first time... trying imgur:]


For those of you keeping track, yes, this has been probably the world's longest valve adjustment.

Thanks in advance!

Soak the gasket remains with one of these. Give it time to work. Ed

Fine emery cloth works great

Thanks, Ed! I actually have some of the Permatex stuff, but found it to be of little use. I may have been too sparing with it for fear of it getting into the engine. Is there any risk there?

And thank you, baldy. Emery cloth sounds like it would be good, but is there any risk of the grit getting inside and damaging the engine?

Maybe I'm being paranoid -- just trying to be a more careful mechanic than my bike's previous owner!

I would stuff some rags around where I needed to put the gasket remover and then put a heavy coat on it using a flux brush. Ed

Have read of others sharpening a small piece of plexiglass/lexan/plastic to scrape with...mebbe sharpen one of those scratch-off lottery ticket scrapers...(looks like a miniature windshield scraper) They usually give them away at your local lottery stop...

I have used a fine honing stone wetted down with some WD-40 to do my final prep on my gasket surfaces for ages.

Then just wipe gasket surface down with a shop rag and some carb cleaner.

Grumpy: interesting idea! I've tried using plastic razors with no luck, but I imagine something like lexan might stand up to the abuse a bit better.

Dr. Gamma: sounds like a good approach -- Is there any risk of bits of the honing stone getting into the engine using that method?

Thanks again, everyone.

My little honing stone is like 3 inches long about 3/4 inch wide and about 1/4 inch thick. If you oil the stone the little grit that there is gets suspended in the oily film.

I have NEVER had any of the stone break away as I lapped the gasket areas.

I think my honing stone was made by Norton.

I bought it back in the late 70's. I use it ONLY on gasket surfaces thats it.

Dr. G: Awesome - any idea what grit your honing stone is? I realize that you bought it some time ago, so no worries if not! Otherwise, anything in particular to look for when selecting an appropriate honing stone?

serfrock wrote: I actually have some of the Permatex stuff, but found it to be of little use. I may have been too sparing with it for fear of it getting into the engine. Is there any risk there?

It's not the same stuff as it used to be. I had a 10-15 yr old can left over from changing diff. gaskets on a 1972 Blazer and it worked great! Would just melt the old gasket and it would wipe off with a paper towel like melted cardboard mush. Ran out of that can and bought a new can and its absolutely useless. Might as well use windex to remove the gaskets.

So now we are back to doing it by hand, slow and steady.....just take your time and be careful.

I changed the valve cover gasket on mine recently when I did my valves, I put it on dry like everyone says to. It leaks, but just a tiny tiny bit, nothing like before when it would run down the front left corner after running. If I do it again I will probably put some sort of sealant, just a tiny amount, on the bottom of the gasket and leave the top dry for easy removal of the cover. See if that seals it up better.

Remember - when you install the new gasket do not use sealer. Just put it on dry and you won't have that problem in the future. Ed