Topic: 1977 CB750K - Project Susanne

[onetruepunk87]

Hey guys, I've been working on my CB750K since I bought it back at the end of February and figured with all of the info I'd accrued from this site I should post the fruits of my labor. This is the second bike I've done, the first being a 1979 CM400T. I used that bike to learn how to ride and to get a feel for fixing these old bikes up. I loved it, but I unfortunately outgrew it and decided to sell it in April to free up some funds to be able to fix up this 750. Here's a before and after of the the CM400T.



And here's the CB750K how I bought it and then shortly after I took off all of the touring add-ons.



I've made a good amount of progress since this so bare with me while I try and post everything up in chronological order.

[onetruepunk87]

After I first bought the bike I was broke and was doing what I could to clean the bike up with the limited funds I had left. The bike had been in storage for a long while before I bought it and at some point moisture must have made it's way into the tank. How do I know this? Because while moving the bike around in the garage I noticed a pinhole leak that wasn't there before on it.

So I drained the tank, filled it with 5 gallons of white vinegar and let it sit. After about 12 hours I flushed it with degreasing soap and water and allowed it to thoroughly dry. After that I got my dad to help solder the the pinhole and I then used Red Kote to seal the tank. About a week and a half later  after the first coat cured I applied a second coat.

[onetruepunk87]

Using a a template I found here on SOHC4 I managed to drill and chamfer the rotor. It took nearly an entire afternoon but it was well worth it.

Thank you to member SKTP for posting the template!

[onetruepunk87]

It was around here that I realized that It was going to take forever to finish this bike without some extra cash so I made the decision to sell my CM400T. It was bittersweet seeing it go. I had spent countless hours resurrecting that bike and making it something to be proud of but at 6'1" i was a bit big on it and after a year of riding experience I wanted something with a little more get up and go. My first purchase was a set of desperately needed new tires.
 


After mounting them, I used a trick I read on here for painting spokes. I took painter tape and used a hole puncher, punched a hole in a strip of tape, then cut the strip in half and placed it around each spoke. It took forever but came out great and was much easier than re-spoking and re-balancing the wheels.

[onetruepunk87]

While waiting on other parts I started on some polishing. I started working on  the forks while on the bike but took them all the way off after this to hit them on a polishing wheel. This was just by hand working up from 400 grit sand paper to 0000 steel wool. I think I did 400 - 600 - 1000 - 1500 - 2000 sandpaper and then the 0000 steel wool. That's what's pictured below, After off the bike I used a polishing wheel with Mother's aluminum polish, you'll see that in a few more pictures.

Used the same process for the brake drum and other miscellaneous aluminum pieces as well.

[onetruepunk87]

Got a nice box of goodies from Dime City Cycles. Note to anyone trying to bend aftermarket K0 badges to fit a K7 tank they won't bend, they will snap though. I tried heating them and rolling bit by bit over an old exhaust pipe for curve. It started to bend at first but ultimately snapped.

So around here I had both wheels off the bike and the bike suspended from ratchet straps connected to the support beams of my garage and balancing on it's center stand. With so much off the bike I decided it would be a good time to clean the engine up and prep it for some paint. I wasn't going to pull the engine because it was running fine so I taped off accordingly. I took the pipes off and here's the results.


And instagrammed for the hell of it.

[onetruepunk87]

After that was done I taped that off and freshened up the paint on the frame.

Scrubbed the hell out of my shocks too and got them shining like new. They looked like they had grime in them that was older than me.

I also got some exhaust collars off of eBay for the new exhaust I'm going to run. They were pretty well rusted when I got them but CLR and wire brushes took care of that.

The 4-2's that were on the bike were pretty rough and didn't need exhaust collars to go on. The headers were in pretty good shape after I cleaned them but the mufflers had broken off on both sides where they connect to the passenger pegs and had been welded up before. The one weld had failed already and I got my dad to braze it for me. He got it but it wasn't very pretty looking since there was no meat left to attach to. He also had to braze the underside of the pipe that was cracked from it getting stuffed before. I looked into getting new mufflers but they were nearly the price of a new exhaust so I just picked up a MAC 4-1.

[onetruepunk87]

Polished Forks re-attached, new headlight brackets, wheels, foot pegs, cleaned and polished front fender and my brand new seat on the bike. Starting to look like a bike again. I threw the tank on real quick to see how it flowed with the tank. I'm incredibly happy with it. I had the freshly painted caliper attached as well but I got some brake fluid on it while reattaching it and well the caliper paint bubbled right off. So I drained it fully and prepped the caliper for another go.

[onetruepunk87]

Soon after I got the new headlight bucket, turn signals, speedo, tach, handlebars, and controls all mounted. I ended up having to drill the headlight mounts out a few sizes to fit the turn signal stalks. For the rear turn signals I simply cut the stock turn signal stalk short so that the new ones would fit right in the end, just had to add a washer in the back. I also repainted the handlebar controls. Still have to connect all of the wiring but I found a "cheat sheet" for the speedo here on SOHC4, compliments of Boulevard_beck. I tested all the connections using his diagram and they all work! This really saved me a big headache. Tach and turn signals are pretty self explanatory plug and play. Not sure what I'm going to do for a taillight but I'm leaving this one for now. I used a small Lucas style on my 400 and liked it but it seems to small for this bike. Also, I'd like it to be more visible since I ride home from work at night so If I do change it I'd like something at least close to a DOT approved size.

[onetruepunk87]

This brings me just about to where I am with the bike right now. I started prepping the tank for paint. I ordered some Spraymax 2k two-part, single stage paint. I used their clear on my last bike so hopefully this stuff works just as well. I ordered the paint from 66 Auto Color. It's a paint, clearcoat, and hardener all in one. I actually have an extra can of clear left over from my CM400 so I'll be putting it over this paint, it should really make it pop. The color I got is Highland Green, same color as the '68 Mustang in Bullitt.


Here's where I'm at, one coat of primer on the tank.

This was taken just after I primed it. After sanding the primer there are a few little knicks I missed so I dabbed some filler putty on them and sanded them flat after drying. I'm waiting on a nice day to prime again and then hopefully paint.

[jerry h]

Cool -   That shade of green should look nice........

[onetruepunk87]

Thanks Jerry, I've had that color in mind for awhile now...

Finally finished wiring up all of the new electronics and got it all back into the headlight bucket. With the help of the cheat sheet I posted before it was a breeze. It definitely saved me a headache having all the wiring sorted out. I hope Boulevard_beck doesn't mind me posting it here but I figured it would help out anyone working on a 77-78. I really love the look of this headlight. It has a modern looking glass lens but also has a small illumination bulb in the housing that gives it an old school yellow look when lit.

I wanted to get another look at how everything looked all together again so I threw the tank and side covers back on. I'm really happy with the overall look and profile of the bike. Should be even nicer once the new exhaust is on.

I also did some repair work/modification on the sidecovers. The left hand side cover had a nice crack running down it that had been "repaired" by someone by drilling holes into either side of it and zip-tying it together. They did the same to reattach it's top right mounting tab. I repaired the tab by dremeling each part a bit and j-b welding it back on. I had to do a similar repair on my CM400 when I got it and it held up so I think this should too. For the crack I also used some j-b weld and just added a little filler putty on the surface. You might notice I also decided to change out the side cover badges to the original 750 styled emblem. So I found a spot on the cover where they'd sit flat and used the original mounting points as a reference to get a straight line and drilled. I just filled the original holes with more putty. Hopefully I can do some more priming this weekend, weather permitting, and then lay some paint. I'm really excited to ride this. Not being able to ride on nice days is killing me, every time I hear a bike go by I get jealous.

[onetruepunk87]

I got everything primed and sanded last night and woke up early this morning and got to work painting. After bad weather all last week I finally caught a break and got a perfect day for it. No humidity, barely any wind, 70 degrees, and sunny. Got my tank, tank lid, and side covers painted and cleared both in Spraymax 2k. The results look great. The paint is a little pricey but it sprays like a paint gun and is fuel resistant so you won't ruin all your work if you drip any gas on it. I actually overestimated how much I needed and only ended up using 2 cans of color and my one can of leftover clear from my old bike. I thought I'd go into the 3rd for sure and bought a 4th can for insurance since the color cans are only 6oz each. Oh well, I'll have extra in case of emergency. If you're gonna be using this stuff be sure to do it in a well ventilated area and use a respirator. The stuff is no joke, the can is covered front to back with warnings and skulls and crossbones. That's how you know it's the good stuff

Pictures are from before I cleared so they look even better now.

[KRONUS0100]

nice work.  where did the guages come from?

[onetruepunk87]

Thanks! The gauges are from Dime City Cycles. They have a few varieties of them in chrome and black powder coat with either black or white faces. Also the tach comes in different ratio's depending on your bike, this one being a 1:4 "for Honda CB750's and other large CC Metric bikes."

[onetruepunk87]

Got the bike pretty much reassembled. Still working on touching up the paint on the original tank badges though. I'm having some issues getting the bike to run right, It starts up but it needs the choke pulled all the way out, I let it warm up but it stalls once I close the choke halfway. I'm going to have to pull the tank off and connect a longer hose so I can play with the idle and sync the carbs. I'll have to wait a few days though since my tach cable broke while messing with everything.

[Schnell]

Love that seat. Where'd you get it?

[onetruepunk87]

The seat is from eBay seller "hondaclassic31" they have a bunch of different style seats available.

http://www.ebay.com/itm/1977-1978-Honda-CB750K-CB750-K-cafe-complete-seat-/181125053534?pt=Motorcycles_Parts_Accessories&hash=item2a2be4fc5e&vxp=mtr

[deafcaferacer]

Damn man, that is a beautiful engine. I am jealous. That green works very well with all that alum.

[Schnell]

The seat is from eBay seller "hondaclassic31" they have a bunch of different style seats available.

http://www.ebay.com/itm/1977-1978-Honda-CB750K-CB750-K-cafe-complete-seat-/181125053534?pt=Motorcycles_Parts_Accessories&hash=item2a2be4fc5e&vxp=mtr

Thanks!

[onetruepunk87]

So remember that leak in the gas tank I sealed? Turns out, I didn't . Lesson learned, test before painting. So after a day of being pissed off I got to searching for a good replacement tank. I found one on eBay with very clean inside that only required a little body work. So after a couple days of fixing a some dents and waiting for more clearcoat I was able to paint again. This time I checked that the tank held gas beforehand. I also cleared my tank badges while I was at it.



As for the problems I was having with choke and stalling out all it took was a little bit of tweaking the idle adjuster. With the new tach cable hooked up I got it idling just where it's supposed to be. It runs great now, but I'm still going to sync the carbs, I split the cost of a motion pro carb sync tool with my brother so I just have to take an afternoon to do it.

So after the paint dried I put everything back together and it looks great! I got insured and registered and rode around all yesterday afternoon with a big dumb smile on my face! I drove it to work this morning as well and it actually made going to work on a Sunday enjoyable. Here's a cell phone picture I snapped out back of my work.

It's going to rain the next couple of days but I'll take some more pictures with a good camera once the weather clears up.

[antman180]

The bike looks great !!! Looking at the Shinko 712's as well, and like the size/profiles of yours - What size tires did you end up going with??

[onetruepunk87]

Thanks! The front is 110/90-19 and rear is 130/90-17. They're a quality tire for the price, I've only put a few miles on these but my brother had them on his KZ400 and they performed really well.

[onetruepunk87]

I only ever put the one "finished" picture up so I figured I'd post a few more. Here's just some cell phone pics for now, I'll have to go somewhere cool with a good camera and take some quality shots.

[cheftuskey121]

Beautiful color man! What seat is that?