Author Topic: 1972 CB 750 restoration after a 40 year nap (Read 16939 times)

autotec · « **on:** October 18, 2015, 10:38:24 AM »

Below is the start of the project I brought home yesterday. My uncle bought it brand new in late 71 and parked it in 75 after covering only 7K miles. Looking the bike over, everything seems to be there and in decent shape besides a couple pieces of chrome that are badly pitted and a rusty fuel tank. I still have to decide what route and how far I go with it, but whatever I decide, it should be fun. I look forward to all comments and suggestions. Let the fun begin!

Thank you, Justin

Stev-o · « **Reply #1 on:** October 18, 2015, 10:40:57 AM »

As original and complete it is, plz dont cafe it!

You could start by soaking the tank in vinegar or trying the electrolysis method to remove tank rust.

754 · « **Reply #2 on:** October 18, 2015, 10:47:29 AM »

It looks like an early 72.

Lease try cleaning the chrome first before writing it off.. Better to have original with some wear, if it can look presentable..on a nice survivor bike..

autotec · « **Reply #3 on:** October 18, 2015, 10:48:27 AM »

Quote from: Stev-o on October 18, 2015, 10:40:57 AM

As original and complete it is, plz dont cafe it!

You could start by soaking the tank in vinegar or trying the electrolysis method to remove tank rust.

No, no cafe treatment for this one. I will have to change the bars though, I need to make some room for me.

I was just about to run to the store to buy some washing soda to try the electrolysis method.

autotec · « **Reply #4 on:** October 18, 2015, 10:50:53 AM »

Quote from: 754 on October 18, 2015, 10:47:29 AM

It looks like an early 72.

Lease try cleaning the chrome first before writing it off.. Better to have original with some wear, if it can look presentable..on a nice survivor bike..

The few places I tried cleaning turned out pretty good. With a little more effort, most should come out great. I'll take a few more pictures soon.

Stev-o · « **Reply #5 on:** October 18, 2015, 10:51:09 AM »

Hard to tell from the pic, but those may not be origina bars?

autotec · « **Reply #6 on:** October 18, 2015, 10:53:55 AM »

Quote from: Stev-o on October 18, 2015, 10:51:09 AM

Hard to tell from the pic, but those may not be origina bars?

I'll have to look at some pictures and compare, I just assumed they were.

dusterdude · « **Reply #7 on:** October 18, 2015, 11:08:51 AM »

Nice bike

754 · « **Reply #8 on:** October 18, 2015, 11:32:09 AM »

Clean steel wool and soapy water will not harm chrome.. Steel wool is cheap.
Stay away from the scouring ans Sos Type pads with abrasives..will scratch up the chrome..

edwardmorris · « **Reply #9 on:** October 18, 2015, 11:55:06 AM »

Welcome!

Yay! another early K2 goldie

Late 71 purchase is most likely the rare super early K2s. If you'd rather not post the VIN, an easy way to tell eary vs late K2 is the wording on the dash panel. Early ones have NEUT, later ones have NEUTRAL label for the neutral light respectively. Its hard to tell from the angle but yes, it does look like the handlebars aren't original. Gas tank will take some work and the Carbs will definitely need a full and thorough cleaning. You can download the factory manual from these forums and try the 3000 mile tune up and fire it up with cleaned carbs and an aux tank (if in a hurry

).

oldhatt45 · « **Reply #10 on:** October 18, 2015, 12:04:48 PM »

autotec,

She's a Beauty!!!!

For cleaning the Chrome up, try some Colonel Brassy
http://www.amazon.com/Colonel-Brassy-16-Surface-Cleaner/dp/B004N0IZNC

Works really well. Takes some elbow grease, but generally will bring the chrome up pretty nice.

And I believe those handelbars are NOT original as others have said.

Charlie

rinkeldekinkel · « **Reply #11 on:** October 18, 2015, 12:14:14 PM »

good nice looking project!
Sounds pretty much like the one i found,
Is the steel on the inside of your tank thin?
Mine can be pushed in at the fuelcap...

Good luck on your project!!

Desert-SOHC · « **Reply #12 on:** October 18, 2015, 12:15:22 PM »

Coke soaked 0000 steel wool will clean the chrome right up without damaging it.

HondaAddict · « **Reply #13 on:** October 18, 2015, 12:32:12 PM »

Nice looking project bike. Keep us updated!

Evaporust does wonders on a rusty tank. I used it for my V65 Sabre, which sat with an empty tank for 14 years. I put in a gallon and let it soak, turning it every day for about a week. Looks great now.

https://www.evaporust.com

autotec · « **Reply #14 on:** October 18, 2015, 01:52:21 PM »

Thank you everybody for the kind words, the picture makes it look better thank it is though. (don't they always?) Metal seems ok on the tank, I cant push it in by the cap. Just got back from the store with some supplies, so time to start cleaning the tank.

Below I'll post a few pictures of the VIN and the dash. Looks like it's a early one. One question though, what's the difference between the early and late ones?

Thanks, Justin

Stev-o · « **Reply #15 on:** October 18, 2015, 02:05:41 PM »

Hey Mo - I think it's a later K2 as it does not have the K1 gauges.

autotec · « **Reply #16 on:** October 18, 2015, 02:15:31 PM »

Quote from: Stev-o on October 18, 2015, 02:05:41 PM

Hey Mo - I think it's a later K2 as it does not have the K1 gauges.

I called my uncle for more history on the bike. The gauges were replaced at one time after a accident, sometime in 72. With that, the bars were replaced too. He cant remember if the bars were the same or not.

edwardmorris · « **Reply #17 on:** October 18, 2015, 03:38:33 PM »

Quote from: Stev-o on October 18, 2015, 02:05:41 PM

Hey Mo - I think it's a later K2 as it does not have the K1 gauges.

IINM, only the very first batch of US K2s (fewer than 800) had the K1 style gauges. All the rest had the dash panel. Mine's a 11/71 too, but its still 4000 ahead of this one.

@autotec The early K2s have a lot of oddities. Handlebars are one of them, K3+ had a different style, K0-K1s had a different style and K2s had their own

Early K2 have the dash like yours and mine, later ones have different wording. Even later ones have similar gauge faces but different internals (damper fluid vs. magnetic) etc. etc. Its a pretty fun with all its peculiarities

autotec · « **Reply #18 on:** October 18, 2015, 04:59:23 PM »

Quote from: edwardmorris on October 18, 2015, 03:38:33 PM

Quote from: Stev-o on October 18, 2015, 02:05:41 PM
Hey Mo - I think it's a later K2 as it does not have the K1 gauges.
IINM, only the very first batch of US K2s (fewer than 800) had the K1 style gauges. All the rest had the dash panel. Mine's a 11/71 too, but its still 4000 ahead of this one.

@autotec The early K2s have a lot of oddities. Handlebars are one of them, K3+ had a different style, K0-K1s had a different style and K2s had their own Early K2 have the dash like yours and mine, later ones have different wording. Even later ones have similar gauge faces but different internals (damper fluid vs. magnetic) etc. etc. Its a pretty fun with all its peculiarities

Ah, thank you for the info. Just finishing up on some cleaning, I'll post some pictures soon.

autotec · « **Reply #19 on:** October 18, 2015, 05:14:56 PM »

Here is the rust I found in the tank. I figured I would try the vinegar first, then the electrolysis as a last resort.

Thanks, Justin

oldhatt45 · « **Reply #20 on:** October 18, 2015, 05:36:32 PM »

autotec,

Try the Klean & Strip brand Prep & Etch (Home Depot carries it.)
From what I can see in that picture, I'd think the Prep & Etch wouldn't take more than an hour or 2 to clean it up.

Charlie

autotec · « **Reply #21 on:** October 18, 2015, 05:51:21 PM »

Quote from: oldhatt45 on October 18, 2015, 05:36:32 PM

autotec,

Try the Klean & Strip brand Prep & Etch (Home Depot carries it.)
From what I can see in that picture, I'd think the Prep & Etch wouldn't take more than an hour or 2 to clean it up.

Charlie

I will give that a shot if this doesn't work, thank you. But so far, it seems the vinegar is working. This is after only 2 hours. It's a little hard to see, but I see some clean metal in there.

Stev-o · « **Reply #22 on:** October 18, 2015, 06:04:07 PM »

Looks to be cleaning up real nice.

autotec · « **Reply #23 on:** October 18, 2015, 06:05:10 PM »

While I'm waiting on the tank to un-rust, I figured I would clean the bare bike so the dissassembly would be cleaner. (if that's a word) The only issue I ran into was the removal of the plastic side covers. After 40 years. they did not want to come out. But with a coating of silicon lube, they finally came out without breaking. After a degreasing, I was impressed with the finish on everything. It almost looks new. Almost.

Desert-SOHC · « **Reply #24 on:** October 18, 2015, 06:10:44 PM »

Looks purdy

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Author Topic: 1972 CB 750 restoration after a 40 year nap (Read 16939 times)