New guy with new old bike

[Walmart Ninja]

Hello. I bought a 1972 CB750. It does need some love in the cosmetics department. What is a good method of cleaning the rust, faded chrome, white crusty stuff on the forks, engine, etc etc. I always thought the shape of these old bikes was the epitome of a cool old badass bike. But it's gonna take a while to get her up to speed, fo sho. Hopefully you all can help me on the long, arduous journey.

I don't know if I can post pics yet as a new guy.

 

[hinksy]

I just nut and bolt rebuilt a 77 supersport and it can be a lot of hard work . The engine has clearcoat on it , mine was black satin paint . So that has to be removed before you can make it look good , same as the fork legs , I was going to just clean her up , but the more I looked , the deeper I went , till I had it down to a bare frame . Once stripped I could see that it had to be done as the frame/electrics/brakes were a mess . Aluminium foil in a ball with crc is good for the chrome , it`ll get rid of surface rust , but deeper needs a converter and a soak , then possible rechroming . Most of the nuts and bolts on mine had surface rust , so I wire wheeled them to clean them up and soaked them in evaporust . One day I might try a bit of plating to spiff them up . All the alloy , so fork legs and engine bits , look really good when polished . But again that requires stripping . It took me about 3 yrs all up from purchase to finished bike , so it is a love job , but just go bit by bit , do some youtube searches and take your time , you`ll get there

 

[UK K6]

That's been my experience also. I found, unless you have a replating kit, whatever you do to the nuts and bolts doesn't last. I've steadily replaced all of those that are easily visible. Most alloy and chrome responds to the more gentle metal polishes.

I found off the shelf engine paint doesn't withstand ethanol without flashing over with an ethanol proof clear coat.

My approach was to get it running, identify what needs doing mechanically to make it run well and reliably and only upgrade cosmetics in the areas I was working. Other than blasting and powder coating my frame, only because the engine had to come out, I left expensive shiny stuff until I had the bike running, riding and stopping well and requiring no more major work (he hopes!). That way, the bike was never off the road for more than a month and I hadn't spent loads before I knew it was basically sound.

 

[Walmart Ninja]

Thanks for the advice guys. Yeah, gotta get it running here too. Waiting on points and condenser. I rebuilt a 1975 Triumph TR6 (car) from a bare chassis, so I am aware of how much fun it is. I am wondering how much good rust remover will be. For the Triumph, there weren’t really chrome or shiny pieces for the mechanical stuff, so I used lye and acid and other bad stuff to remove crud and rust on parts before repainting them. These parts are chrome and nice, so I’m out of my element . I look at the engine specifically and wonder what the hell I should do with it.

 

[Walmart Ninja]

Hinksy, that bike looks sharp!

 

[hinksy]

That was going to be my plan , till I found out that if a motor sits for 30 yrs , that it doesnt want to play

 

[hinksy]

Hinksy, that bike looks sharp!

Thanks Ninja , good old parts even are not cheap , so depending on your budget , it could cost you a lot . Mine came in around the 12 000 usd mark , phew ! Have a look at brickhouse builds and hackaweek , even motorcycle rewind on the youtubes , lotsa hints on how to clean them up there

 

[Walmart Ninja]

Hinksy - Ouch! This motor does turnover which is good. And I have a video of the PO with it running from a couple days ago. He just lost spark recently, so maybe it’s not going to be too bad, mechanical wise. Hopefully.Not looking to make a concours ride here. Just make her look nice and be reliable for when I take her out to terrorize the civilian population.

 

[UK K6]

I did everything myself apart from the frame powdercoating and cylinders borescope measurements and re-hone. Mine was turning over, non-runner, rusty frame with awful hand brushed sections, ripped seat, but good tank. 2 destroyed carbs, a bad head, hole on the rear fender and a cracked rear brake lining. I sourced a 2nd hand head, head cover, rear hub and a bank of carbs. I bought a David Silver seat and Vietnamese chrome fender. I went through everything. The bike now looks pristine, almost concours and runs like a dream. I spent almost £3k to get there. Had fun doing it.

Edit: the challenge is knowing when to stop. I am waiting delivery of a replacement rear grab rail, as the original looks shabby against the new fender. The only remaining issues are a small stain on the inside of the speedo glass and light pitting on my mirror stalks. I'm leaving these things as a reminder of what I've achieved!

 

[PWBII]

Always a labor of love these bikes. As an aside I got hooked on these when my cousin gave me a ride on his '76' & promptly did a wheelie when we took off. (with both of us on it!) & no, I didn't fall off. Might I add, I find the point eliminator set-ups to be very advantageous to these bikes points & condensers are getting pricey when you can find them. Buy the eliminator & time it once & your set!

 

[Walmart Ninja]

Thanks for the inspirational tale, K6!

PWB, I am waiting on points and condenser from the PO before diving into this and trying to get it started. I am in the dark on the points eliminator setup. Right now sitting on my hands waiting to start!

 

[PWBII]

Points eliminator will replace your whole point plate w / wires & the cam on your advance unit. Time as usual once & done forever. here's a pic of it.

 

[hinksy]

Andy mechanic , brickhouse builds and hackaweek show how to set up your points

 

[Walmart Ninja]

Thanks guys

 

[Walmart Ninja]

I watched a couple hackaweek videos. He goes deep on the motor. deep deep.
If the bike runs and shifts, is there any reason to tear the motor apart looking for problems or potential problems? I have a tendency to "If it ain't broke, I'll fix it till it is" that I try to avoid.

 

[hinksy]

I would just check the oil filter if you are worried . Run it , see if it sounds ok ( they rattle like hell ) and drop the oil and check for sparkles . If it is all clear and there is no major noises , you should be golden

 

[dirtdigger]

The biggest thing to worry about is the timing chain tensioner and primary tensioner wheels coming apart. The rubber wheels get hard and brittle and start to break apart, makes chains rattle more and can eventually break the chains. you can drop the oil pan and check for chunks and other debris. The oil pump check valve rubber tend to leak as it gets hard and doesnt seal well, that causes the oil tank to drain back to the engine pan.

 

[Walmart Ninja]

Good info - thanks guys!

 

[hinksy]

This is what you will see

 

[carg3]

I also got a 1972 back in March. It was not running. The bike had been sitting for over 10 years but the engine was turning. All I did to get it back on the road was:
- Replaced plug caps (old ones had no resistance).
- Changed spark plugs.
- Cleaned carbs.
- New oil, oil/air filters.
- New battery.

Check coil resistance, and adjust the cam chain tensioner

Regarding the chrome. I have been succesful removing surface rust using 0000 steel wool and fine scotch brite to remove the white crusty junk from aluminum.