Cleaning engine mating surfaces

Hello all,

I'm working on the engine to a 1976 KZ400S and I currently have the top end dissembled. While the block and head are off, the mating surfaces should be easy enough to clean the old gasket off of, however my concern lies with the crankcase gasket surface. What is the best way to prevent the gasket remover and the remains of the old gasket from falling down into the crankcase while cleaning? Will a rag stuffed down into the base of the cylinders be sufficient?

Also, is it frowned upon to use a brass bristle brush or wheel in my dremel to clean off the stubborn gasket?

Thanks in advance.

Even though I had rags stuffed in and was careful I spilled so much ...... decided to take the motor out and rigged it up to a auto stand then took off the pan and sprayed it out with WD-40 and brake cleaner flipping it over 3 or 4 times.....You probably should do this anyway as you'll find the pan and oil pump a dirty mess and this way it was spotless...... I used razor blades (be careful though) and maybe nylon wheels if not and not brass.

I use rags, scrape it off then flush with diesel while the drain plug is open. Shop vac first of course.
Steve

patience and lots of time comes to mind LOL. Frowned upon? If you use the least preferred method compared to the most preferred but end up with the desired results, there's nothing to frown upon. That cat image is something else.

Permatex gasket remover dabbed on with a brush softens the gasket nicely. Get the old style gasket remover, not the low VOC crap, which doesn't work nearly as well. It takes a while to remove the gasket if it's the petrified original and it may make take several applications of the sauce. Just take your time and avoid the crud going down the crankcase.

Alright I'll pick some of that up from the local auto parts store and give that a try. I'll post before and after pics hopefully later this week when I have some time to work on it.

Is it safe to soak the head and block in a degreaser like purple power? I'm going to do exterior cleaning as well while i've got it apart.

ZeffRides wrote: Alright I'll pick some of that up from the local auto parts store and give that a try. I'll post before and after pics hopefully later this week when I have some time to work on it.

Is it safe to soak the head and block in a degreaser like purple power? I'm going to do exterior cleaning as well while i've got it apart.

Negative on that purple stuff. It's super harsh and will corrode the aluminum.

I use an old chlorine tablet bucket with a lid. Put the head or cylinder inside, dump a gallon of carb dip in the bucket, install the lid and shake every time I remember. The dip will soften the baked on crud and carbon after a few days. Works great.

Nessism wrote:
Negative on that purple stuff. It's super harsh and will corrode the aluminum.

Phew glad I asked on the purple stuff! Thanks!

Don't know if this helps but ...

I did this a lot on old VW engines with great success - apply a little grease on the edges of the case where you will clean, this way the grease kinda' holds all the "shavings" together and sticks to the razor blade as you scrape it off. Ditto on being uber careful with the blade to not knick the casings.
This trick also works when you may have to machine a part of the case (like drilling out an old stud / bolt boss. Putting some grease on the drill bit helps to collect the filings/shavings on the bit.

Yup.
Steve

ZeffRides wrote: Hello all,

I'm working on the engine to a 1976 KZ400S and I currently have the top end dissembled. While the block and head are off, the mating surfaces should be easy enough to clean the old gasket off of, however my concern lies with the crankcase gasket surface. What is the best way to prevent the gasket remover and the remains of the old gasket from falling down into the crankcase while cleaning? Will a rag stuffed down into the base of the cylinders be sufficient?

Also, is it frowned upon to use a brass bristle brush or wheel in my dremel to clean off the stubborn gasket?

Thanks in advance.

I crammed blue shop rags into the area where the rods come up and tucked them in at the edges. I used a single sided razor blade and my wife's vacuum..... scrape a few inches then slurp up the crud so it can't work it's way into the engine.

bountyhunter wrote:

ZeffRides wrote: Hello all,

I'm working on the engine to a 1976 KZ400S and I currently have the top end dissembled. While the block and head are off, the mating surfaces should be easy enough to clean the old gasket off of, however my concern lies with the crankcase gasket surface. What is the best way to prevent the gasket remover and the remains of the old gasket from falling down into the crankcase while cleaning? Will a rag stuffed down into the base of the cylinders be sufficient?

Also, is it frowned upon to use a brass bristle brush or wheel in my dremel to clean off the stubborn gasket?

Thanks in advance.

I crammed blue shop rags into the area where the rods come up and tucked them in at the edges. I used a single sided razor blade and my wife's vacuum..... scrape a few inches then slurp up the crud so it can't work it's way into the engine.

I'll bet the wife was glad you lubricated the vacuum for her. :whistle: