Topic: Gasket SERIOUSLY stuck

[NewOldSchool]

In the last two weeks I have removed the head and cylinder block from my 1974 CB750 engine.

The head has now been completely disassembled so that I can clean it and rebuild it. When taking the gasket off it had stuck to the head and was like brittle plastic. I have peeled it off and scrapped with a razor blade the best I can, but some gasket material remains like its welded to the head.

How can I get this material off??? Can I uses a fine grit sand paper like 600 or something?

[lucky]

Snap-On gasket scraper.

[CycleRanger]

In the last two weeks I have removed the head and cylinder block from my 1974 CB750 engine.

The head has now been completely disassembled so that I can clean it and rebuild it. When taking the gasket off it had stuck to the head and was like brittle plastic. I have peeled it off and scrapped with a razor blade the best I can, but some gasket material remains like its welded to the head.

How can I get this material off??? Can I uses a fine grit sand paper like 600 or something?

Soak it with solvent. Scrape scrape scrape 

[NewOldSchool]

The head is also seriously mucky with oil and grease and dirt outside from the leaky head gasket, as well as lots of carbon in the combustion chambers and exhaust ports.

Can I use Simple Green as long as I wash it off extremely well? Aside from media blasting (I don't want to have to repaint the head its in fairly good condition) do you have any other tips?

[CycleRanger]

Use some foaming engine cleaner and some stiff nylon brushes and a brass brush.

[Rob69]

In the last two weeks I have removed the head and cylinder block from my 1974 CB750 engine.

The head has now been completely disassembled so that I can clean it and rebuild it. When taking the gasket off it had stuck to the head and was like brittle plastic. I have peeled it off and scrapped with a razor blade the best I can, but some gasket material remains like its welded to the head.

How can I get this material off??? Can I uses a fine grit sand paper like 600 or something?

You can try gasket softener compounds, but I've never had much success with them. I've found that patience and countless hours of careful scraping is the best way. I wouldn't sand or be tempted to use a die grinder with any of the 3M attachments that many recommend for gasket removal.  You will damage the aluminum mating surface(s). Very expensive to have repaired at a machine shop (if at all). I learned the hard way.

[NewOldSchool]

Thanks, I tried the smallest gauge (softest?) wire wheel attachment on a power drill at medium speed and pressure and it just polished the area a bit. I quit almost immediately and will go buy a scraper. 

[BobbyR]

This may be of some help to you. I did a google search on removing gaskets and a few Honda and Kawi forums showed up. Here is a video that looks pretty good.

Honda-Tech: How to Remove tough gaskets

[NewOldSchool]

Thanks all!

[Harsh]

Mine was the same way.  I used some gasket remover stuff from the auto parts store.  It softened it a bit, but it took a number of applications, a fair amount of elbow grease, and a lot of patience.

What are you going to do for replacement gaskets?  You might want to check Honda Service Bulletin #42  http://data.sohc4.net/SB750/750_42.pdf
It might just be my kit, but so far I am missing 4 o-rings from my Cycle-X complete kit.

[chewbacca5000]

Hondaman suggested I use permatex foaming gasket remover.  Put it on and let soak overnight.  It really helped things out.

 http://www.jpcycles.com/product/424-567?utm_source=none&utm_medium=cpc&utm_term=&gclid=COOPsIPAn7ECFYFo4Aod2n-UYw

[Rob69]

This may be of some help to you. I did a google search on removing gaskets and a few Honda and Kawi forums showed up. Here is a video that looks pretty good.

Honda-Tech: How to Remove tough gaskets

I'd be very cautious. We used that technique when I worked at a dealership (time is money). The shown method works, but you have to have be very light-handed. It's not hard to irreversibly mar an aluminum surface. If time isn't an issue, I'd err on the side of caution and use a gasket scraper, followed up by dressing any imperfections and cleaning residual baked-in gasket material with a very fine stone and some lubricant.

[Accolay]

Those roloc bristle disks look promising, but still might be kinda rough. Green is 50 grit equivalent, yellow is 80, and white is 120.

http://www.3m.com/product/information/Roloc-Bristle-Disc.html

[dave500]

sharp gasket scraper and caution,hold it squarely,the unwitting will hover too long in one spot with a power tool,not such a problem with cast iron though,use the power tool for the left over problem spots.

[NewOldSchool]

I bought a scraper from O'Riley and the damn thing isn't flat! I makes gouges on one corner. I'm going to return it and get a brand name one from Sears or somewhere reputable.

I was able to get the head really clean with a brass wire brush and half a bottle of Simple Green (I rinsed the head off for nearly 30 min after to make sure there was no residue left over. That got all the gasket material off and the face of the head very clean.

I then took a very small screwdriver and lightly chipped all the stubborn carbon away from around the valve pockets, being very careful around the valve seats. After that I dried it off extremely well and put a film of motor oil on all the seats.

Now I have to clean the jugs in the same manner and take them over to Valley Cycles to get freshly honed.

[saxamaphone]

Hi all, I'm having a similar issue to many here.  I took the head and cylinders off in order to replace rings but getting the gaskets off is holding me up big time.  I'm embarrassed to bring up an old thread like this but I've been trying various brands of gasket remover (they did nothing), razors blades and plastic scrapers but they're not doing anything.  The razors at a 90º don't really take anything off and when I try to go flat along the surface I inevitably scratch up the surface.  I'm at a bit of a loss.  Here's what I'm working on:





Then the base gasket that's also rock hard (I took what I had stuffed in the holes out for the photo):





I don't want to go the route of power tools but I was wondering if anyone has run into remnants of gaskets that were seemingly impossible to get off and how they eventually got it off.  Once I get most of it off I'm planning on scrubbing with SOS pads or scotch-brite and mineral spirits.

[fendersrule]

I've used a very "fine" wire wheel (soft) and was able to easily get it off that way.

But for a larger area that you have, the above recommendations seem good. Tray spraying some aircraft paint remover and letting it soak. Still probably have to scrape, but it helps soften it.

[martin99]

Grind the end of a broken hacksaw blade to a single knife edge, makes a good scraper that you can use nice and flat. Other than that it's patience, patience, patience. Some good music and a few beers help. Don't be tempted to go the power tool route, you'll only fcuk it up.

[Dimitri13]

Take it to a machine shop. Have them hot tank it, remove the stuck on gasket, and maybe even deck it

I did when I got tired of spending hours scraping off (and gouging) the gasket off the top case.

[Vinhead1957]

Straight edged razor blade

[calj737]

You can get ScotchBrite discs to attach to your drill and use them dry or in conjunction with solvents. Either way, they're soft enough to not damage the metal yet have enough grit to bite while spinning rapidly.

The other tool I used on my head was a paint remover wheel. It's plastic material, like a flapper wheel. It'll strip paint to bare metal, but won't scar the metal. Electric drill, not battery operated. Or a compressor driven grinder with these attachments.

[edwardmorris]

Acetone + ATF is pretty popular.

I've had great luck with just wetting 1000grit sanding paper on a block with acetone itself and gently scraping off the most stubborn bits. But not everybody seems to think sanding even with that fine a grit is smart.

[mcswny]

The answer is simple and its the same answer when one asks "whats the easiest way to get carbs on"

And the answer is.... drum roll please.... Have someone else do it!

Kidding. There's a million good ideas here and they all work for the individual user. Choose your poison and move slowly. Put on some good music and grab at least a 12 pack.

good luck!

[saxamaphone]

Thanks for the tips guys.  I'll keep going on it with a razor I think.  I'll try and soften it as well with some acetone.

[kyre]

I had the same issue as you. No amount of chemicals would "soften" the gasket. Razor blade only took off so much and there were areas where it was hard to get to, also slooooow.  I tried the gasket scraper but it's a bad idea. Too easy to slip and gouge the very soft aluminum.

I have a dremel And ended up getting the "finishing abrasive buffs" attachment and the gasket came off so easy. Of course you should have a light touch (as soon as you see metal slow down) but it's a soft material and doesn't really mar the aluminum if you do end up being a little heavy handed.