Cleaning up the engine

[Bonwit]

I'm looking at buying an early SOHC, probably '71-'74, and have been browsing Craigslist. I notice some bikes' crankcases are mottled, or splotchy, the effect of weathering, I suppose. My question is, to what extent is this fixable? Were the crankcases painted? Is this splotching in a clear coat? Is the only solution to repaint (assuming they're painted in the first place) or can they just be cleaned/polished? Thanks for the input. I want the engine to look good, but I don't want to start a frame-up restoration at this point.

 

[dirtdigger]

Official Honda motor paint color is Cloud Silver. I find that Duplicolor Engine Enamel Silver is close enough for me and won't cost you a ton. The Cloud Silver is available but cost you $50/can for the base color.

 

[Bonwit]

So is it possible to mask off and repaint a case without dropping the engine and taking things apart?

 

[Dinosaurocker]

I wonder too if the 'splotching' is in a clear coat, and if there is any way to help with this short of repainting?

 

[rickgoodspeed]

Hi I am deciding to repaint my engine aswel. There remains only one big question; How do you protect the paint for oil en gas spills? I was thinking about a matt black (engine paint till 650º) maybe with a 2K matt transparent finish?! How would the 2K paint hold on an engine with engine paint?

 

[grepper]

A lot of the covers you can take off sand and polish while the engine is in the frame.

As for paint, your going to need something that can handle high temps and chemicals. Most everything in a rattle can needs to be heat cured. You can do this by running the engine, but there are parts of the case that wont get up to the curing temperature.

I can imagine getting an engine masked off while it's in the frame would be pretty difficult. Last year I painted my engine whole, but out of the frame. http://www.cb750.com/threads/595-CB750-K5-Restoration/page2?p=7641&viewfull=1#post7641

But after getting the bike on the road I found out I needed to rebuild the engine, so I'm repainting is in pieces and curing it in the oven. http://www.cb750.com/threads/595-CB750-K5-Restoration/page7?p=13308&viewfull=1#post13308