Topic: 1977 CB750k restore project

[dgilling]

I went to change my sprockets, chain, front disk, and brake lines, and now I have the bike taken down completely to frame and motor.  I've always wanted to restore as much as possible and I guess now is the time.  I'm not looking for perfection, just better and I want to keep it running as good as it does.  The bike is rusting out in lot of places, electrical was in pretty bad shape.  I would like to do small things to the engine, but I don't want to mess with it too much.  I did the carbs a while back and don't plan on messing with them.

I bought the bike 8 years ago for $300 and rode it almost every day when I lived in California.  I've since moved to Colorado and being the winters are much longer she doesn't see as much action.  I wish I would have started this project in the winter. 

I hope to clean it up pretty good but I don't want it to become a money pit.  I plan to replace the important things and do most of the work myself.  I can't decide if I want to get the frame powder coated or just try and paint it myself.  I feel like sandblasting would save me a ton of cleaning time and if it's at the shop getting sand blasted I might as well get it powder coated, along with the wheels and other parts. 

Here is my list.  Let me know if i'm missing an important one.   
To do:
Rear wheel
   -Remove old rusted spokes
   -Order new spokes
   -Powder coat wheels
   -Polish hubs or paint black??
   -Order/Install new bearings
   -Lace/true rim
   -Mount/balance tire
Front wheel
   -Remove old rusted spokes
   -Order new spokes
   -Powder coat wheels
   -Polish hubs or paint black??
   -Order/Install new bearings
   -Lace/true rim
   -Mount/balance tire
Front/rear Brake
   -Order new Godferry Rotor
   -Order new sling shot brake lines
   -Rebuild caliper (maybe) needs some new screws for sure.
   -Clean/polish rear brake pedal
   -Clean/install rear brake light switch
Frame
   -Clean and powder coat or paint
   -Clean/Install inner fender
   -Remove rear fender rust and possible paint black, considering bobbing the fender
Body
   -Remove cap and petcock from tank, strip paint and prep, recreate the skull stencil
   -Replace Headlight fork ears with new ones or polish and remove rust on old ones
   -Strip/prep headlight bucket
   -Clean/polish fenders and misc shiny parts
   -Order new turn signals
   -Order new Cateye taillight
   -Order new brighter headlight
Suspension
   -Replace front fork seals
   -Paint lowers
   -replace springs with progressive springs
   -stanchions have damage, which damages the seal, replace or repair
   -Polish up rear springs
Engine
   -Clean
   -Paint?
   -Polish covers and shiny bits
   -Paint black background on alternator cover, possible replace alternator cover.
   -Replace valve cover gasket
   -Inspect/replace cam chain tensioner
   -New Header gaskets
Airbox
   -Replace case
   -replace rubber boots, but they're so damn expensive!!
Gauges
   -Replace with new smaller ones, they speedometer doesn't work anyways
Electrical
   -Clean and replace as necessary

[SOHC4 Cafe Racer Fan]

A restoration is inherently a money pit, but the end product is priceless.  It's not a financial investment -- it's a fun investment.

[dgilling]

These are my original photos of the bike when I got it 8 years ago.  The skull will stay, i'll need to recreate the stencil somehow.  I thought for sure i'd go all flat black but I see some gloss black and I'm starting to like it.  Not sure what to do now.  I painted the headers and they stayed black for a long time but is starting to fade again.  I've also dented the gauges and the front fender.  Other than that it looks pretty much the same. 

[calj737]

Regular exhaust paint will not survive on these pipes. They get heated from the inside-out and the rusting generally occurs due to condensation build up internally, thereby attacking the paint adhesion.

For best results, have the inside of the header pipe treated with a ceramic powder coat, then paint or ceramic coat the outside of the header. This will preserve the pipe and reduce the header temps, and improve exhaust gas scavenging.

For your stencil, seek a vinyl sign maker. HB know, the guys who make the stick-on advertisements for cars, trucks, etc? Take a scan or digital file of your image, they will die cut it onto vinyl. Get mirror images for either side of the tank, and a few smaller/larger scaled versions. Spray the base color of paint you want the stencil to be, then apply the stencil. Then spray your top color, remove the stencil to reveal the base color, then top coat. Voilá!

[dgilling]

This restore might come with a lot of dumb questions so please bare with me.  I've done a lot of searching on the forum to try and find answers but sometimes it's easier to just ask and get a quick answer. 

How do I decide on what to paint and what to powder coat?  I'm getting close to having all the parts removed.  All that is left is the motor from the frame.  Then I need to make a decision on what to paint, powder coat, or clean up to shiny chrome again. 

Any one have suggestions on their favorite products and methods for removing rust from chrome?

I hope a lot of people subscribe to this restore because I'm going to need the help. 

[chewbacca5000]

Wow looks like a very ambitious project.  Be sure to take one major system at a time and you will be fine.  If you are looking for original color on the frame it is around 80 to 85 percent gloss.  Keep the pic coming.

[calj737]

Rust removal from chrome: soak some aluminum foil in water, then rub the chrome with it. It will remove surface rust very well with little expense, and no chemicals.

Paint: body work is best painted as it allows the greatest flexibility in style, colors and materials. Talented and experienced powder coasters can do amazing things, but they are hard to find in many places locally.

Powder coat: frequently chosen for frame, swing arm, brackets etc. Essentially the heavy metal items that need the extra protection that powder coat provides, and where durability is preferred. Cleaning powder cost is simple as water, or soapy water. Doesn't suffer from water spotting either and the shine (if you on choose gloss finish) pops right back.

Polish: many folks choose to polish side covers and "highlight" pieces if they paint/powder cost their engine. It's a ton of work, but looks fantastic. The part must be very clean before you begin the polishing steps to insure the best finish. Work you way through sanding (starting about 80 grit for heavy tarnish and scratched areas, maybe 120 for average wear areas) then step to 320, then 400, then wet sand from 600, to 1,000 to 2,000. Then, move to cotton wheel on a buffer, stepping though the 3 different rouges. Simple  . Requires lots of beer.

[dgilling]

Thanks so much for the reply.  I hope to start cleaning tomorrow after I get the motor all the way out with a buddies help. 

I pulled the lowers off the forks tonight and removed the seals.  One was leaking.  The race has a pretty big gouge in it.  Should I try and file it smooth? 

It was tough to get the lower allen bolt out too.  The piece on the inside just kept spinning with the bolt, even with an impact wrench.  I head to create a wedge and hammer it down on it to hold it. 

Here are some of the parts I removed.  Any feedback is welcome and encouraged. 
Rust on Spokes.  Hoops actually look rust free. 




Dent in front fender, I want to modify this one to be smaller anyways. 




These pieces on the header just fell off when I removed them, and I think there's supposed to be a copper gasket in there but I see no evidence of one.  The fourth cylinder seemed to leak oil out the header gasket but i could never really tell for sure because of other leaks.


Brakes are going to need some new parts


Fuse Box.  Do you think this will clean up?  I looking to pinch pennies where ever I can.  Especially on something that is easy to replace down the road. 


Cb750k by dustygillingham, on Flickr

Battery must have leaked some acid
Cb750k by dustygillingham, on Flickr

I've never really known what this part on the bottom of the battery box is for.


Rust on bottom of the fender
[url=https://flic.kr/p/nvd7SK]

I'm pretty sure i want to replace these.  I have some from a 750 custom that look like the same part and are in a little better shape but I might just want to replace all together.
[url=https://flic.kr/p/nbWUfo]

Headlight box with the previous owners on/off switch. 


I'm probably just going to put these same shocks back on save the replace for another day when I recover from everything else.


Gauges will go, speedo didn't work anyways but I believe that's the original miles. 

[dgilling]

The bike feel over a in my garage a long time ago and cracked the alternator cover.  I JB welded it, and it held up for a long time.  Starting to flake now.  I want to just replace but holy cow those things are expensive.  Any ideas to repair?

[dgilling]

A good portion of battery acid leaked down here.  I'll make sure to install a proper drain hose!


Top of rear fender
[url=https://flic.kr/p/nt9rN8]

I did my best to take some pics of the exhaust.  Pretty messy.  I'm not even sure what it should look like on the inside.  Every valve doesn't look the same though. 
[url=https://flic.kr/p/nroQrU]

[url=https://flic.kr/p/nbWL3F]

[url=https://flic.kr/p/nbWWtG]

Notice the top of the spark plug.. Things are pretty white and corroded.  The actual electrode on the plugs looks pretty good though. 
[url=https://flic.kr/p/nvdabH]

[calj737]

Copper exhaust gaskets: Yours are there, they are crushed, and do reside in your exhaust ports on your heads. I can see them clearly from the picture you posted (mentioning the valves). Replace them when you put the motor back together. You'll need to dig them out of there.

The "shells" are the 2-piece shims that fell off. They install under the flange when reinstalling. Orient them on either side, held in place during install with a little dab of anti-sieze or grease. Having the seams 12:00-6:00 aides in water escaping through them.

Rust on chrome: try the aluminum foil trick on the ears and fenders. You might be surprised... You can use a Rust converter spray to treat the underside of the fenders, then spray an undercoat on them to help future corrosion and to protect them from road grime, rocks, etc... It's like an aerosol Line-X. I believe Eastwood offers it. You can use it on your battery box too.

Member Edwardmorris has a resto thread going on. Look back a few pages and he details exactly these steps and products.

That fuse box will clean up. Reapply dielectric grease to the plug ends when installing.

Spokes: I would replace them. It's a safety issue, not a cosmetic issue. You can locate NOS ones, or, buy stainless ones ($2@ from Buchanans) and never have the issue again. But don't save penny's with your safety on an old bike.

Fork lowers: if the gouge is internal, and the race is mucked up, definitely needs to be repaired, else it will fail again. In the future, loosen the Allen bolt at the bottom before you disassemble the fork. The tension of the springs and fluid help hold the nut just enough. An impact wrench helps too with the torque to loosen/unwind it.

[dgilling]

Should the shells be replaced? It looks like in this case the shells are in one piece. http://www.powersportsuperstore.com/Mac-4-Into-1-Canister-System-Black-201-2601-p/4156378.htm?Click=35177

Nice to know on the forks.  I was following the clymer manual.

Any ideas on the alternator cover?   

[calj737]

You'll only need to replace the shells if they are damaged. You can omit them on some aftermarket systems. Or use those supplied with the aftermarket system.

The covers for your year are 1-piece, earlier years were a 2-piece design. The cover is aluminum, so if you can TIG weld, you can grind out the JB Weld, and re-weld it permanently. That will require some refinishing of the part afterwards. Or, you can look for a used one. Member Stilltime is looking to trade 1, his is like yours, but he wants a 2-piece. Perhaps he will sell it. Or, you can PM Bill Benton and see if he has one.

Else, post up a "Wanted" ad in the section of the forum for parts you seek.

[dgilling]

I got the motor out tonight, but had a casualty.  I bent the engine bolt that connects to the pegs and mangled the threads on it, but motor is out and on to cleaning now!  I'm definitely going to have to come up with a more graceful way to mount the motor.  We had to wiggle and wobble that thing to get the frame off. 

Do I spend anytime cleaning something if I'm going to get it sand blasted anyways?  It seems like that would be a waste of time. 

[calj737]

You say sand blast, what are you having sand blasted? Frame and other bracket bits? That's fine.
Don't blast the motor with glass bead or aluminum oxide. You'll be required to tear down the entire thing to extract all media from the internals of the engine. You can soda blast the engine in an assembled state, this is much safer.

Yes, degrease it before blasting. Whether you are going to sand blast the parts or have them done. Powder coaters have to first degrease before blasting to avoid contamination of the media.

Two ideas for you: 1. Set up a stack of magazines on the right side of the motor. Lay the bike onto them, then lift the frame off the motor. Reverse sequence for installing. This puts the motor a bit higher in huge air and avoids mangling the motor hangar bolts, and gives some extra clearance from the ground so you can manage your hands in there.

2. Contact member 754. He will sell you a no-weld frame kit. This sections portions of the top rails and truss to allow you to remove the engine much more easily and service the head with the motor in the bike. In fact, you can install the lower end only, then install the upper with the use of frame kit. Well worth the expense for the ease and benefit of all other matters.

[dgilling]

I was planning on having the following items media blasted (not sure which one) and powder coated a matte black finish. 
frame
swing arm
fork lowers
center stand
battery box
alternator cover
gear shift cover
valve cover
battery caliper
wheels
hubs

I planned on painting the following items:
Gas Tank
Fenders
side covers

[AintNoEasyWay]

Sweet. The skull logo is badass. Restoring a K7 as well. Subscribed.

[Chaser60]

Your call on budget with regard to PC.   If you want to save a little money, you will find that rustoleum products (in a gloss of to match your PC parts) will work out great for things like battery box, gage bracket, dummy lights housing, ignition bracket etc.   Any of the small, non outward or highly hidden parts can be rattle can painted.   Some folks have found PC guys that basically quote the big stuff and will toss in the little items for another small upcharge.   If you can find that, have them all done.   

As someone said above, the money just keeps flowing out.   I am past what I could ever get for this bike for sale, but when done, I will have a one of a kind bike that winds out to 10 grand on the tac for less than 5k.    Smiles per dollar spent will be very very high.

Cheers and good start.

[dgilling]

I just bought a sand blaster with soda conversion kit from harbor freight.  Everything for under $200.  I also started calling around about powder coating prices and some places are pretty reasonable for blasting and coating.  One guy quoted me $200 for frame, swing arm, and some extra small stuff. 

Should I just take the blaster back?  I still have to do the motor so I'm thinking i'll get my money out of it there.

The other problem is I need to build up a place in the garage to do the blasting.  Hmmmm?

 

[calj737]

Soda blasting is generally a lost-media process. Often blasters do this outside, so not sure soda blasting in a garage is a great idea. If you do blast in a cabinet, you'll need to seal it really well and connect a strong vacuum to pull the dust as you go. Also, a quality compressor is needed to maintain sufficient CFM to produce enough pressure.

Your choice though. It's nice to have a blasting cabinet when you fab and strip stuff.

[dgilling]

I don't have the best air compressor but according to the numbers it can manage the blaster. It seems like the $200 for the blaster would be better spent towards new parts. Especially if the shops around here are pretty reasonable.

I think ill return it and just try and manage without it.

My biggest concern is how do I clean in between the fins on the motor without a soda blaster?

[calj737]

Elbow grease! Actually, lots of folks use solvents, degreasers, brushes, etc. it will come clean.

The best approach in my opinion, is Simple Green. BUT, get the aluminum safe formula (blue label). Wash, soak, rinse. Repeat. Scrub. Repeat. It will come cleaner than you think with effort and no $.

[dgilling]

I've got elbows so this crap is going back to the store. I hope to get in some good cleaning sessions tomorrow.

Any good threads on cutting and modifing the front or rear fenders? I've looked around but didn't find much with details. I'm sure I will have more questions after tomorrow.

Thanks or the advice. Always appreciated.

[dgilling]

Well I didn't get much done this weekend considering I had to fix the lawn mower and mothers day.  I did accomplish some things though. 

I disassembled the brake caliper.  The hoses were cracked in multiple places and there was a ton of rust inside the caliper.  The brake fluid in the caliper looked like black sludge.  I'm so surprised that it actually stopped.  I also removed the first part of the engine.  Things don't look pretty in there.  I'm afraid to take off the rest. 

Notice the black sludge coming out of the caliper


This is about as clean as I could get it.  Do you think it's okay?  Can I replace just the o-ring?  I can only find the oring for sale with the piston, and I think my piston is still good.  I also need a new hard pipe for the brake line.  I can't seem to find that either. 



Oh, boy... looks like a mess.  Bolts were rusted pretty good. 


Does this Race come out before powder coat?  Will I need to remove this I'm i'm putting all balls bearings in there?


Is this salvageable or will I need new fork tubes?  Doesn't seem like it will buff out.


Last question is do i remove the old bearings from the swing arm before powder coat?  What's the best method to remove those? 

[dgilling]

I found the o-ring here http://www.partzilla.com/parts/search/Honda/Motorcycle/1977/CB750K+A/FRONT+BRAKE+CALIPER/parts.html#uloc25

But there are two part numbers listed.  Which one do I need?