Cleaning top end parts. Have some questions.

[JE4570]

Hi all,
Doing a top end rebuild and need to start cleaning up my parts. Question1: Should I avoid soda blasting gasket surfaces when I go to soda blast?

As far as the head goes, should I pull the valves out and clean the carbon with a wire dremel before soda blasting? Or could the soda blast remove carbon? Is there a safer way to remove carbon from the head that doesn’t involve me potentially ruining something.

As far as the valves themselves is there any danger to using a wire wheel to clean these?

I know its important to get rid of carbon before lapping to avoid fouling up the surface, other than that, are there any more dangers I should be aware of before I dive in headfirst?

 

[5twins]

You can use paint stripper to remove the carbon from the head, piston tops, or where ever else you've got a build-up (exhaust ports maybe). It will probably take several applications. But it won't remove the carbon on the valve faces, it's too baked on. But they're hardened steel so once removed, you can wire wheel them clean. Just avoid the seats around the edges if you can. Once the valves are removed, stuff strips of oiled rags in the guides to keep junk out and protect them while you're cleaning stuff up.

 

[Paul Sutton]

I found that a very thin layer of carbon/gum build-up in the valve guides can prevent the values from rotating during operation. This rotation comes about due to the lash/tappet screws striking the end of the valves off-center. This is by design and the rotation helps keep the valve/valve seat clear of carbon build up. Cleaning the carbon film out is somewhat difficult. I did it by using a thin strip of cloth with Autosol polish followed by thorough cleaning to remove polish residues. See the following thread:

http://www.xs650.com/threads/engine-valves-not-rotating.49609/

In Entry 21 TM (TwoManyXS1Bs) points out that 30 Cal (8mm) rifle bore cleaning brushes are very good for this cleaning job.