Author Topic: 79' DOHC CB750 Canadian Build  (Read 1986 times)

Offline Nust

  • Posts: 14
79' DOHC CB750 Canadian Build
« on: Nov 07, 2017, 11:00:46 »
Greetings guys and gals,

I'm still a pretty new member to the forum but thought I'd start a thread for my current project and share my work and probably ask a few questions along the way.

So I picked up this 79 cb750 sitting just as you see it here in the truck.

This past weekend I started working on it at the shop.  Stripped everything I didn't need, chopped off and ground flat most of the tabs (still got a few to do).  The plan is to re-wire the bike including the install of an m-unit blue. I swapped a 17" spoked wheel onto the back to replace the comstar wheel it had. Next I'll chop up the subframe to add a hoop and flatten it out. My plan will be to raise the rear some to accommodate that and lower the front to get level.  The rest of the build includes a new pipe for the 4-1 header, clip ons, new controls, round headlight, new gauges, rebuilt forks with progressive or racetech springs and new shocks on the back. Lithium battery to be hidden and then a motor rebuild. Treat the whole thing to powder and paint and I havnt decided on a style of rubber yet.

Any input or thoughts are always appreciated and considered but not always followed.

Offline Nust

  • Posts: 14
Re: 79' DOHC CB750 Canadian Build
« Reply #1 on: Nov 11, 2017, 18:28:06 »
Got some more work done on the project today. Tore down and removed the engine out of the parts bike finally also. If you need some stock cb750 parts from a 79 just msg me.

As for the project I sliced up the subframe and tacked a piece of tube on to mock up the levelled look and check for issues, fit etc. Seems to work so now I'll bend up the hoop and weld it in place of that piece I test fit. 

Getting the motor out of the parts bike was more work then expected. Makes me think maybe I'll just reassemble the rebuilt engine inside the frame one piece at a time instead of trying to avoid scratching anything installing it as one piece.  Anyone got a suggestion on that?

Offline TheCoffeeGuy

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Re: 79' DOHC CB750 Canadian Build
« Reply #2 on: Nov 12, 2017, 10:58:02 »
Where in Canada?  I am just outside Toronto. Not your ordinary Blog site.

1968 Harley Aermacchi ML 125 Rapido, restored
1972 Honda Cl 450 engine rebuild, a day rider soon, now sold
1980 Suzuki GS850GL Street Brat  My other day bike
2000 Harley 1200 Sport S My day bike
1982 Honda CB650 Chopper light

Offline coyote13

  • Posts: 1187
Re: 79' DOHC CB750 Canadian Build
« Reply #3 on: Nov 12, 2017, 16:02:06 »
Not sure on the DOHC but on the SOHC CB750 the head is not able to be removed or replaced with the engine in frame, you may want to check clearances before you start assembling the engine in frame
Half the fun's in the get there...

Offline Nust

  • Posts: 14
Re: 79' DOHC CB750 Canadian Build
« Reply #4 on: Nov 12, 2017, 19:30:46 »
Coyote thanks for the info, I'll double check that but I'm sure I'll be putting the motor into a bare frame when it's all been powder coated.

Coffee guy I'm in Sudbury about 4 hours north of Toronto

Was gonna fab and install a hoop today but rushed a bit and kinked my tube when I was bending it. Sadly was the last of my tube so I'll have to get more tomorrow and get that done.

Online pacomotorstuff

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Re: 79' DOHC CB750 Canadian Build
« Reply #5 on: Nov 17, 2017, 08:17:27 »
Ah, another Canuck. 
Nice project - the frame mod is a good one.
I, too am just outside of Toronto (northwest of it) - but don't have a hangar to work on my bikes in LOL.
Pop me an email when you're getting ready to look at some bodywork - we've been supplying folks with our made-in-Canada fiberglass products for over 15 years...
Keep posting your progress.
P.S. nice Cub, must really dance with the O-235 on the firewall.

Offline Nust

  • Posts: 14
Re: 79' DOHC CB750 Canadian Build
« Reply #6 on: Nov 18, 2017, 16:01:41 »
Well I got back to work on the hoop today and after a couple kinked attempts at the bend I got it. So as you can see I still have to cut its length as it's way to long and still needs a 20 degree upward bend. Either later tonight or tomorrow I'll take care of that and weld it all up.

Paco, thanks for the advice, I'll certainly reach out once it's time for bodywork but it's mostly just going to be the tank.  As for the cub I can't honestly speak to it. Belongs to the father in law. I've been up once and given my fear of flying it certainly seems to move.  Luckily his interests extend to bikes and under his extensive tutiledge We've done some cool work. As for the flying and the work on that thing I stay well clear lol.

I've also attached the last project we finished in the spring. 

Offline teazer

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Re: 79' DOHC CB750 Canadian Build
« Reply #7 on: Nov 18, 2017, 17:27:19 »
That hoop looks like it's the right length, but would look better with a slight uptilt at the rear.

Offline Nust

  • Posts: 14
Re: 79' DOHC CB750 Canadian Build
« Reply #8 on: Nov 18, 2017, 20:21:38 »
Hey Teazer, plan is to put a 20degree upslope on it.  Its gotta loose at least 3-4" to be to my taste.  If I was keeping a café bump on the back then maybe it would be fine.  Just gonna finish with an upslope and a thin seat to go with a brat style look in the back. 

I appreciate the interest guys feel free to chime in with suggestions or ask some questions.

Offline Nust

  • Posts: 14
Re: 79' DOHC CB750 Canadian Build
« Reply #9 on: Nov 25, 2017, 17:26:17 »
Well I got a little more time in on the cb today, bent the hoop up on a 20 degree slope, trimmed it to length and made some slugs to weld it up. I'm gonna just clean up its portion around the shock mounts before I finish weld it.

I also built a small box for the bikes electrics in the form of an M-unit blue and tucked that away under the tank just above the carbs. Not sure how welll you can see that in the pic.

Tomorrow I'll finish weld the hoop and build a seat pan.