Topic: Just got my free project bike

[mooperdee]

I got my hand-me-down CB 750 today.  I'll definitely need some advice from the members here.  First, I'll need to clean everything so I can assess overall condition.  Most of the bike isn't a problem, but the head is off and has been off for, well, a really long time.  It obviously needs cleaning. 

What is the block made of?  If everything is iron or steel, I might be in trouble.  The surface I can see is a uniform brown color.   I haven't touched it yet.   It's been stored in a shed under very low humidity, so maybe it's just real dirty.  How do I clean this stuff off so that I can see what's underneath without screwing anything up?  I'm afraid that whatever I clean with will get into the cylinders and damage something.

[mutters]

 Mate get used to working with aluminium,your head,crankcases and cylinder block are (should be !) aluminium
 the cylider liners are steel ,so there could be some rust apparent there.
 hopefully you've just got to deal with dirt
 good luck, Jeff

[TwoTired]

Cleaning can be done with a stiff bristle brush (non metalic) and simple green for an eco friendly proceedure.  Water based solvents usually leave bare exposed metal prone to corrosion that a spray of WD-40 immediately afterward will arrest.

However, if you have the proper disposal facilities, mineral spirits (yes - paint thinner) works pretty well.  Plus, if any gets into your crankcase, you can just drain it out without too much of a rust worry.  Kerosene doesn't clean as well but leaves a very thin oily film behind to deter corrosion, Diesel fuel, too.  The environazi's would rather you rusted, recycled, and replaced your machine with a new one more under their control.  And thus, discourage use of these older but effective cleaning methods.

Cheers,
 

[cadler]

Why was the head off? you may need to do a top end.
Also, is the engine on the bike? You may need to remove the engine to get everything back together. Is the cam chain visible?

[mooperdee]

The head was off because the last owner was planning to replace gaskets to fix a small oil leak.  He got it apart and then just decided not to finish it.  He just gave it to the guy that I got it from.  The engine is off the bike.  Yeah, I can see the timing chain.  It's got safety wire tying it to one of the head bolts so it won't fall in.

BTW, I got a look at the ID plate.  It's a '74.  The odometer shows 49K miles.

[mooperdee]

Oh, by the way, how do I know if the bike is a K or an F?

[luckysox]

If its a 74 it's a K  They didn't make the F until 75

[mooperdee]

The plate on the frame says it was made in 01-74.  I guess that makes it a K.