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'79 CB750F Super Sport / Engine Finish

Luis Etchenique

'79 CB750F Super Sport
Messages
57
Reaction score
14
Points
8
Location
South Ponte Vedra Beach, Florida
The engine of my restoration functions well, and all it needs is to recover its original shine.

This is the silver-painted version, but I'm not interested in re-painting; can I soda-blast the engine as a unit ? ( engine has been removed from frame ).

All openings ( exhausts, carbs, etc ) have been properly sealed, and I intend to thorouly clean-up any residue prior re-install.

Has anyone tried this ? Any comments or suggestions ? ( vapor-honing is out of the question due to its potential to penetrate the unit ).

Thank you as always.
 
Never did an entire engine before and including carbs. I'd consider blasting media past seal edge like output shaft. What kind of soda? If mixes with water likely OK. Get around spark plug bases good when cleaning up. You have vent openings in carb bottom of bowls. The screws do NOT cut those off. The choke shafts and butterflies use flimsy foam seals to stop entry of dirt, getting too close or too much shooting pressure can distort or tear them and will get inside somewhat
 
https://photos.app.goo.gl/qtPLVhKjeaEKrKps7

https://photos.app.goo.gl/TCgZj7F5f599vMSU8

... I saw these pics on the cb750.com FB page, and looks like the owner has prepared his engine quite well for a soda-blast session. Clever stuff !

All intake & exhaust ports are safely sealed as well as vent hoses etc. ( I need to find out what kind of hardware he is using to seal those ports ).

In my case ( like him ) I won't need to worry about the carbs -- which have been removed.

As soon as I complete my exhaust fabrication, this will be the next step.
 
They look like automotive rubber engine freeze plugs which you can get in various sizes. Be careful using them, they can apply enough force if overtightened to crack the intakes to ruin head. Tighten while twisting them and quit at tight enough you can't twist any more or just barely. DON'T go tighter! They don't have to be super tight to deal against air blasting.

I've used those plugs hardwired/bolted in place on a header both ends to then pressurize it with 100 psi air to then heat header with a torch locally to red to let bangups and big dents push back out. A well banged up Kerker header came out looking like brand new doing it. Do the work outside, if you blow one of those plugs it will go straight up maybe 500 feet!! BTDT, it could kill you.
 
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