Topic: CB750K4 what did I get myself into?

[calj737]

A better “current” approach is to use silicon bronze. Has all the merits of lead without the hazards. It melts at a much lower temp than steel, won’t rust, is easily sanded/ground flush, and can be applied with Oxy/Mapp/TIG/MIG processes.

[BrockCB750]

Thanks for the suggestions on fixing the dent. I will think about what I want to do.

I am making progress removing the paint and rust. It is REALLY slow going but its getting there.

[BrockCB750]

Clutch tool came in fits perfect. Pulled the tab back. But... It just spins the entire clutch. In neutral or in gear.

How do I get this thing off?

[BrockCB750]

Should have seen this coming. Haha.

Did some googling there are no good options.

I think at this point I am going to test that the rings are good. Still need to Google exactly how to do that but if they seem okay I think I am going to call the lower half good and get the head gone over and replace all the rubber and gaskets cylinder head up and call it good. There was not a spot of rust internally I have seen. No signs of water intrusion. I think I have a good chance of being good to go.

[70CB750]

Clutch tool came in fits perfect. Pulled the tab back. But... It just spins the entire clutch. In neutral or in gear.

How do I get this thing off?

You need two tools.  One to hold the clutch and the other one to loosen the nut in the center.  I made these way back.   You can borrow them, I will not be using them anytime soon.

Or maybe an impact wrench would do but I never tried that.

[PeWe]

I have used a piece of wood that blocked front sprocket.
Higher gear in.

Last clutch jobs with engine in bike. 5th gear, plank block rear wheel to roll.

[BrockCB750]

I think I finally made up my mind about what direction I want to go. Going to brain dump here.

Condition of bike parts...

Trash:
exhaust unrecoverablely rusty
rear fender
wheels and tires
shocks
anything electrical

Salvagable:
Frame
Engine (no rust inside, needs a lot of elbow grease to clean it up)
Carbs (complete rebuild)
Airbox (all new rubber needed)
Rear and front brakes
seat (maybe)
oil tank (rusted, dented)
gas tank (rusted, dented)
Front fender (Dented and bent might be able to save it?)

Good:
Nothing

This is not going to be a full on restoration and was never really in the cards but resto-mod in a cafe-leaning style. The goal is to have a safe, comfortable and rideable bike that I think looks great.

Things I know I want to do:
- Keep the airbox and carbs. I don't want to deal with tuning a breadbox or pod filters.
- Repair the gas tank. Smooth over the badge areas.
- Keep the electronics mostly original.
- Attempt to save the front fender and paint it.
- Get a replacement front wheel in its regular 19" size
- 4 into 1 exhaust (probably delkevic)
- New wheels from Buchanan
- Euro-style handlebars
- Remove the flange everyone cuts off the frame
- Paint the frame semi-gloss black

Things I am pretty sure I want to do:
- Keep original seat mounting. (no frame hoop)
- Get replacement side covers with original badging
- "Delete" the rear fender
- Remove the tabs that the rear fender parts slide into (really don't know if I am going to do this or not)
- Keep front and rear signals
- Leave chain guard off
- Get a replacement rear wheel in larger 18" size
- Get a new seat. (I like brown leather, but outside of that not sure yet)
- New IKON shocks
- British Racing Green (BRG) paint for tank and side covers.
- Limit the amount of chrome on the bike.

The next steps:
1) Figure out what I am cutting off the frame. If I leave the rear fender mounting tabs will it look bad, that will be tucked behind stuff right? I don't plan to ever go back to the OEM rear fender but if I don't need to cut something I don't want to.
2) Figure out exactly which flange to cut off. haha. I haven't marked it or even bothered to identify it in the chaos of the disassembly. Need to make sure I mark that clearly before taking the cutting wheel to it.
3) Once frame is cut finish the endless amount of prep getting rust, paint, grease etc off.
4) Decide if I can live with the dent or if I want to fill it. JB Weld? idk probably just live with it.
5) FINALLY primer the frame.
6) Send out head to get rebuilt.
7) Order wheels and tires.

[Mark1976]

   Whew!!!!! Got coffee or what!!!

[BrockCB750]

Haha! I hit a wall... I was getting a bit overwhelmed with my parts list and trying to figure out what to do next. I needed to just brain dump and organize my thoughts and thought I would do it here.

I want to attack it in chunks now. Current goal is to get the frame on wheels and rolling. Surprising amount of choices and work need to get done to even get there.

[Mark1976]

   No really,  I hear ya, completely understand. One thing at a time and what can I afford,  or spend and not be overwhelmed.  Get your frame squared away, painting, fenders and the cosmetics, you'll be surprised by what you'll spend. I really like Buchanan's,  but let me tell ya,  wheels, quality wheels are pricey, look at the alternatives. Pulling the engine together so that it'll look and perform to yours or anybody's satisfaction isn't cheap, especially when you start paying others to do things you not able to perform yourself. I always have to remind myself, "there are no short cuts." Unfortunately the only way to not waste your financial resources is to spend it wisely the first time. Doing things twice is just plain expensive. Take your time, ask plenty of questions, in the long run you'll save time and money. Really great thread so far...

[BenelliSEI]

The best solution for nice (inexpensive) wheels is to buy a truing stand and build your own. My son sand blasted and powder coated a rusty set of rims black (you can do any colour). Spent less than $100 on a set of aftermarket spokes and cleaned/ polished the original hubs. Using my stand, he built a lovely set of rims for a couple of hundred dollars, and learned a new skill! He then mounted and balanced (on the same stand) new tires, saving even more. Watch a few videos and go for it!

[Mark1976]

The best solution for nice (inexpensive) wheels is to buy a truing stand and build your own. My son sand blasted and powder coated a rusty set of rims black (you can do any colour). Spent less than $100 on a set of aftermarket spokes and cleaned/ polished the original hubs. Using my stand, he built a lovely set of rims for a couple of hundred dollars, and learned a new skill! He then mounted and balanced (on the same stand) new tires, saving even more. Watch a few videos and go for it!

Really great advice, The rim and spoke sets (from China)on ebay are by all means a cost effective option, and in today's world the vast majority of people wouldn't know the difference between a re pop wheel set or a set from Buchanan's. I've been building wheels since I was 12, my last set of carbon wheels for my bike (triathlon) cost more than any motorcycle wheels I've ever built, it's not difficult by any means but it's not everyone's cup of tea either. Yet when your done you've learned a skill that very few people would ever attempt to do these days, but that's the purpose of the project in the first place. Doing what few do today, learning by doing....

[calj737]

Resist cutting the frame until you have shocks in hand, seat, and signals. THEN and only then, make any cutting decisions. Painting a frame should be the last thing to do after you have completely mocked up the bike. Otherwise it will get scratched and changes in decisions will occur causing repaints or shortcuts to the final build.

[BrockCB750]

Waiting to cut/paint the frame is advice I am going to take. Thank you!

I think today I will disassemble the swingarm and the rest of the triple tree and look at what I need to buy to get those rebuilt.

[BrockCB750]

The best solution for nice (inexpensive) wheels is to buy a truing stand and build your own. My son sand blasted and powder coated a rusty set of rims black (you can do any colour). Spent less than $100 on a set of aftermarket spokes and cleaned/ polished the original hubs. Using my stand, he built a lovely set of rims for a couple of hundred dollars, and learned a new skill! He then mounted and balanced (on the same stand) new tires, saving even more. Watch a few videos and go for it!

Really great advice, The rim and spoke sets (from China)on ebay are by all means a cost effective option, and in today's world the vast majority of people wouldn't know the difference between a re pop wheel set or a set from Buchanan's. I've been building wheels since I was 12, my last set of carbon wheels for my bike (triathlon) cost more than any motorcycle wheels I've ever built, it's not difficult by any means but it's not everyone's cup of tea either. Yet when your done you've learned a skill that very few people would ever attempt to do these days, but that's the purpose of the project in the first place. Doing what few do today, learning by doing....

My understanding those Chinese "Rising Sun" wheels and spokes you can get at 4 into 1 (particularly the wheels) were very low quality and not DOT approved. I have read some threads here about some QC issues. QC issues don't bother me, I can send them back. I am concerned about them being dangerous. So I figured another place I didn't want to go cheap was a good set of rims and spokes.

[denward17]

If I recall, I got a front rim and all spokes from vintagecb750.  It was a DID rim, whatever that means, but seems to be pretty good quality, wasn't warped or anything and easy to true up.

[BrockCB750]

If I recall, I got a front rim and all spokes from vintagecb750.  It was a DID rim, whatever that means, but seems to be pretty good quality, wasn't warped or anything and easy to true up.

https://www.vintagecb750.com/products/3/suspension-wheel/132/rims-spokes-wheel-seals-tire-valve-stems

Those look very reasonable. Says they are the same company that made the original OEM rims. I am guessing they are steel instead of alloy but for my purposes I don't care much. I also liked the idea of black rims but for this price I could live with chrome. Thanks!

Also just got back in from the garage. These were a huge pain in the ass to get appart. That rust locked them in good. Also you know how I know my bike sat for 40+ years? haha

[Mark1976]

The best solution for nice (inexpensive) wheels is to buy a truing stand and build your own. My son sand blasted and powder coated a rusty set of rims black (you can do any colour). Spent less than $100 on a set of aftermarket spokes and cleaned/ polished the original hubs. Using my stand, he built a lovely set of rims for a couple of hundred dollars, and learned a new skill! He then mounted and balanced (on the same stand) new tires, saving even more. Watch a few videos and go for it!

Really great advice, The rim and spoke sets (from China)on ebay are by all means a cost effective option, and in today's world the vast majority of people wouldn't know the difference between a re pop wheel set or a set from Buchanan's. I've been building wheels since I was 12, my last set of carbon wheels for my bike (triathlon) cost more than any motorcycle wheels I've ever built, it's not difficult by any means but it's not everyone's cup of tea either. Yet when your done you've learned a skill that very few people would ever attempt to do these days, but that's the purpose of the project in the first place. Doing what few do today, learning by doing....

My understanding those Chinese "Rising Sun" wheels and spokes you can get at 4 into 1 (particularly the wheels) were very low quality and not DOT approved. I have read some threads here about some QC issues. QC issues don't bother me, I can send them back. I am concerned about them being dangerous. So I figured another place I didn't want to go cheap was a good set of rims and spokes.

   Those rims are fine, I've done 2 different pair now, one set on a 76 cb550f I rode for an entire summer before selling it. They're not an Akront or a Borrani or Excels, but at their price point, they're a good alternative. And if your gonna build them yourself,  its a good cost effective place to start.

[BrockCB750]

Nice, I think this is the first instance where I have seen someone who bought a pair and went back and got another. I will do a little more research.

[BrockCB750]

Okay looked at the service manuals and it says to remove the clips and the fork tubes come out.

I am pulling on the fork tubes and they are not sliding out. What am I missing?

[calj737]

Did you get the socket head screws in the bottom of the slider (look upwards where the axle passes through) ? Those screws hold the damper rods to the bottom of the shock.

[BenelliSEI]

If I recall, I got a front rim and all spokes from vintagecb750.  It was a DID rim, whatever that means, but seems to be pretty good quality, wasn't warped or anything and easy to true up.

I’ve also used them on several bikes. Excellent quality and look great. If you want black rims, have a local powder coater sand blast them smooth and coat them what ever colour you want. Unless the rims are really rotten, they’ll look good.

[70CB750]

What Cal says.  Also lookup your bike on CMSNL for diagrams, very helpful.

[BrockCB750]

Looks like I missed the allen head here. No other fasteners of any kind left... These allen heads are seized in there pretty good. Going to let them soak in PB Blaster for awhile.

[RAFster122s]

If you have an impact gun or impact (screw)driver (hammer style) they are good about breaking free the reluctant fastener.