Author Topic: Cobra's 76 CB750 F1  (Read 5448 times)

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Offline cobra2411

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Cobra's 76 CB750 F1
« on: April 05, 2011, 08:35:33 AM »
Ok, so up until last year I had always said I didn't want a street bike because I didn't want to get squished by some idiot soccer mom. I have a few friends that are riders that kept on me and I always just blew them off with "ah maybe someday..." I even got a few fixer upper bikes that were free if I wanted to fix them. Still wasn't interested.

My cousin has an 81 CB750 and I've ridden that and liked it. So one day I was cruising CL and searching for CB750's and there it was. About 3 minutes from my house was a 76 CB750. Same year as me!  :D

I had to have it. Life just never would be complete - it was love at first sight.

Anyway it had been a "Project" bike for a number of years and had passed hands several times. They all had good intentions but just never got anything done. The couple I bought it from needed moving money to get to AZ. They made me promise that whenever I got it fixed up I had to send them pictures. I did one better, in less then a week I had it running and on the road and stopped by to see them as they were loading up the truck...  ;D

It was far from perfect - the rear shocks were shot and I would drag the centerstand on bumps, the head bearings where shot and it turned like a mack truck with a bad tire, the electric start didn't work... etc. I kept making small improvements and kept riding and having fun.

So this brings me to this season (I'm from Philly, we have riding seasons...). All I wanted to do was rebuild the suspension, get new rims and tires and replace the clutch. That's all...

But then everybody had something to say about the red frame. I didn't like it at first but it grew on me - it was kind of a rat bike. The best comment about the red frame I would get was "well........ It's your bike......" which was code for "I hate it."

I had the swingarm off (out to Hondaman for a rebuild) and my friends kept saying "The bike's already half apart... Why not paint the frame."

And the restoration was on... Oops.  ;D

Offline cobra2411

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Re: Cobra's 76 CB750 F1
« Reply #1 on: April 05, 2011, 08:46:47 AM »
Now somewhere along the line an F3 realized the love that was being shown to a Sohc4 CB and it moved in...  ::) My next project... These bikes are like potato chips... Can't have just one.

So the frame got blasted, wire brushed, sanded, primed and then painted with a single stage urethane in gloss black. Looks pretty spiffy...

With the filthy lump out of the frame I repurposed a car engine stand and started cleaning. I was going to go black but I was also thinking about a black tank and I didn't want to get too black. I didn't want aluminum either so I looked for a dark gray engine paint and settled on cast iron which took on a bronze hue...  I was going to use a chrome valve cover, as well as chrome side covers but there just wasn't enough contrast to make it "pop". So I painted the originals and I'm going to put them on.

Offline cobra2411

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Re: Cobra's 76 CB750 F1
« Reply #2 on: April 05, 2011, 08:59:52 AM »
Now to do something with the fugly rims... I picked up some Excel dimpled rims (19x2.15 front, 18x2.50 rear) and some SS spokes from Buchanan's. You can also see the black progressive shocks. Whatever budget I had when I started is gone and I'm starting to enjoy the taste of Ramen noodles... I wanted to do Works or Ikon but it wasn't in the budget. So I went with progressives - should be fine for my riding style and a big improvement over the unknown crusty used shocks that I swapped on the bike because the originals were blown.

I cheated on the rear hub and used an aluminum paint. Looks pretty good IMO. I'm going to polish the front hub for a nice classy look.

Anyone notice the printed rim lacing instructions from Sohc4...  ;D Thanks guys! Also my improvised "K" truing stand...
« Last Edit: April 05, 2011, 09:02:30 AM by cobra2411 »

Offline cobra2411

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Re: Cobra's 76 CB750 F1
« Reply #3 on: April 05, 2011, 09:15:26 AM »
Here's a good picture of it right after I got it running and took it for it's maiden voyage. Notice anything about the mirrors?  ::)

Also a picture with clubmans on. I liked them but it wasn't comfortable in the long run so I went back to regular bars.


Offline cobra2411

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Re: Cobra's 76 CB750 F1
« Reply #4 on: April 05, 2011, 09:01:23 PM »
Well I got frustrated trying to true my new rim last night and walked away. Today I called around and only one guy wanted to do it and he wanted $200 per rim!

With my new found motivation I got it to less then .005" on both the hop and wobble.  ;D

I ended up using small pieces of masking tape. On the rim or hub for the hop and left and right side for the wobble. I marked the high and low points and it helped me see what was going on with the rim. Once I saw the high and low spots it all came together pretty quickly - it maybe took a half hour start to finish...

Not much else done cause of work. Not much likely for tomorrow either but if I can get the railings done for the house I'm working on fast enough maybe I'll finish polishing the front hub and get it laced up and trued...

Offline Retro Rocket

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Re: Cobra's 76 CB750 F1
« Reply #5 on: April 05, 2011, 09:34:47 PM »
I like the truing stand mate..... ;D
750 K2 1000cc
750 F1 970cc
750 Bitsa 900cc
If You can't fix it with a hammer, You've got an electrical problem.

Offline cobra2411

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Re: Cobra's 76 CB750 F1
« Reply #6 on: April 08, 2011, 08:28:24 PM »
ENGINE IS IN!

I thought I was going to have to wait till Sunday but my business partner offered a hand tonight and the engine basically leaped into the frame. I took the exhaust studs out as well as the breather cap on the valve cover to make more room. I got the engine up on my home made "C" on the hoist and we each grabbed an end of the frame and in 20 seconds it was around the engine and bolts were going in...

On the bad news side of things I found I have a CB 550 Brake and bracket... Thought I had everything to do my swap. Good news is that I won an ebay auction for a K7 caliper and bracket. Sorry if I beat anyone from here...  ;D Guess I'll be offering up the 550 bracket and caliper. Hopefully the new one comes apart ok and I can rebuild it.

My goal is to be on the road next weekend.

Offline jaguar

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Re: Cobra's 76 CB750 F1
« Reply #7 on: April 09, 2011, 10:17:34 AM »
looking good.

Offline cobra2411

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Re: Cobra's 76 CB750 F1
« Reply #8 on: April 18, 2011, 02:02:54 PM »
And this phase is done!

Worked franticly to get everything done and was interrupted by the GF wanting to get away for a few days... Oh well, she's been patient with me over the last 6 weeks.

Anyway, rims are laced and trued, tires are installed and balanced, swingarm was stripped and painted, new clutch is in...

All that's left is to paint the tank, tail and side covers and recover the seat. I've got a spare tank/tail so I used the existing ones for now and I'm going to work on the spare set and swap them out.

I got the bike finished on Sunday and went for a shakedown run. Today I took the bike to work and made every excuse to ride it around. I should have a couple hundred miles by this weekend and Saturday I want to go over the bike and check for loose bolts, etc. I also want to check the spokes and retrue the wheels if needed.

I also installed new points and did a full tune up. It will now idle as low as 700rpms without stalling. I still have it set to about 1,200rpms warm because it seems to like it there.

My cousin with the 81 CB750 rode it and made a comment about how much lighter my bike was compared to his.  ;D Made me laugh because they're about the same weight. He doesn't believe me and still thinks mine is at least 100lbs lighter then his.
« Last Edit: April 18, 2011, 02:07:09 PM by cobra2411 »

Offline Benny

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Re: Cobra's 76 CB750 F1
« Reply #9 on: April 23, 2011, 07:32:39 PM »
I am digging the valve cover, is that brushed and flat black? How did you go about doing that.
Newbie CB addict