Topic: CB750 K4 Cafe "Project Warhorse"

[solo 2]

OK, a little background info. For the last couple years I've been playing with Yamaha RDs with every intention of doing a proper cafe bike. Fun bikes, but 1 street tracker, 1 roadracer and 1 unfinished roadracer later still no cafe. My original idea was CB350/450 but I got side tracked as I easily do and while looking for ideas became smitten with the CB750.

So after much searching, cursing, head banging, driving, discussing, talking to wishful owners with a "classic", having long conversations with myself on whether to pull the trigger or not, losing a couple that I should've jumped on...I instantly bought the only one I could find within 150 miles, happy that I could mercilessly talk the PO down to $900, only to get it home and realize that between my eagerness and the lighting in his garage I'd just bought an engine that's never had an oil change and about 5 other parts that don't need to be replaced or rebuilt.

So it begins...

[solo 2]

After getting the bike home I started taking it apart and doing an inventory of good parts and things that had to be rebuilt or replaced. In my haste I hadn’t really paid a lot of attention where I should have. The hand switches on both sides were beyond repair, carbs were full of white rust and only good for a few parts, fork tubes were scratched badly, stator cover was gouged from a previous fall, swing arm had about an 1/8” of play, calliper piston is seized, the fuel tank was just that and nothing else on it and finally the frame has a crack in it which oddly runs lengthways down the bottom frame tube under the engine. This was only some of the stuff I had planned on reusing.

So here is an inventory of stuff I’ve acquired since November when I picked up the bike:

JE 836 piston kit
Dynoman DP315 cam
K1 carb set complete
NOS hand controls
CycleX fork tubes
Progressive suspension springs
Fork seals
Tapered headstock bearings
Gas cap assembly
Petcock
Swingarm shaft
Frame grommets
Carb gasket sets

The bike is now totally apart except for the engine which I’m going to leave until some of the smaller assemblies are completed. All bearings and bushings will be replaced and more engine parts to come once I start that. The next big purchase will be a set of Akront shouldered rims and stainless spokes (I’m still screwing up the courage to pull the trigger on that one). The exhaust I’m still waiting on to see which direction I’m going to go, I’m leaning toward a 2-1 system right now.

As for the color I change my mind daily right now, but I keep coming back to the original Flake Orange with original color striping but different pattern as I’m putting knee dents in the tank. Possibly silver which I’ve always thought made anything look sportier. Maybe gold…

I’ll be posting pics as I go and will probably be asking for help/advice along the way, I’m hoping the Hondaman book will go a long way on this project. Ciao for now.

[solo 2]

I think I almost have everything apart now sans motor, this weekend I took apart the caliper, master cylinder, removed the bearing from the wheels, started sanding down the fork tubes and got into the carbs a bit. I'm waiting on parts deliveries and still ordering more.

I ordered some stainless rims off of Ebay, the price was killer and they look awesome. I know they're not as light as the aluminum rims but 2 polished stainless rims for the price of 1 ali, I don't think the performance diff on a non race bike is worth that much. I was going ali just because I needed to replace the old rims and they aren't that much more than the factory chromes. I'll post pics when I recieve them.

Tried the Pine Sol cleaner on some parts yesterday...WOW, works great and I don't get a headache from the fumes. I stuck a single, heavily gummed up carb body complete with slide still in, the slide would barely move at all. An hour or so later the carb was nice and shiny and the slide moved like new, although the lubricating action of the soap probably had alot to do with that. Anyway don't let anyone tell you it doesn't work extremely well. Will post pics tonight.

I also tried the grease gun trick on the siezed caliper, thanks for that bit of info, out in 10 seconds, no fuss. What really amazed me was the fact that the nipple only went in 1 thread, I thought it would blow off but it did the job. Maybe the piston wasn't as siezed as I thought. Later.

[solo 2]

So here's some pics of a carb that's been soaked in Pine Sol for a couple hours, a little brushing with a stiff brush and then I spent maybe 10 minutes scubbing it with S100 polishing soap and a toothbrush. The S100 is nice because it is easily water soluable, I just rinsed under the kitchen tap. For the amount of effort I think the results are great.

[bluesmoke69]

Great start will be watching.

[solo 2]

Stayed late at work and drilled the rotor, nice to be a machinist when you're working on bikes. I'm looking at building some custom rearsets next possibly but I need a roller so I can locate them so it might be awhile yet.

[solo 2]

I’ve got a fair amount done lately, carbs are rebuilt, forks are ready to put back together, I made a new stainless piston for the brake calliper and right now I’m just polishing everything. Polishing is much easier than one would expect, it’s more time consuming than anything. I’m getting some pretty good results without going too overboard. I ordered some POR15 Glisten PC to clear everything with, I’ll let everyone know the results when they’re done. This stuff is supposed to stick to even highly polished metal and be water clear, we’ll see.

My stainless rims came in and I was wrong about their weight, they’re incredibly light and look great, not perfect but very nice. Spokes are coming from Bucanans. This will be the next project as soon as they get here. I’m also thinking about making a bunch of custom brass parts if I decide to go with a color that will fit.

I keep changing my mind on what color the bike is going to be and what other modifications I’m going to do, the big problem seems to be that it looks like everythings been done to death with these things. Every time I get an idea I take a look around and it’s been done, sometimes almost exactly to what I’d imagined. I want something nice and simple, clean looking, so I’m just going to go ahead and do what pleases me and if it looks like another so be it. When you see a bike that is close to what you had imagined and it’s done well it’s hard not to take things from that bike. I just hope after all this money and time the bike will live up to my expectations.

[solo 2]

Recieved my Ikons today, nice looking units, $400 to my door from Columbia Car and Cycle in Nakusp, B.C.. Awesome service, mine were actually in stock, the owner is famous for Laverda parts but also owns a K1 and K2. I'd highly recommend this place to any Canadians and anyone else looking for some interesting parts.

[solo 2]

So I’ve got a fair amount done in the last couple of weeks, most of my polishing is done, just the hubs left which look to be a pain, I think I’m going to take them to work and recut the centers so they’ll polish up nice. I received my spokes from Buchanans, very nice 7 gauge no taper stainless, should look chunky.  I finally decided on an exhaust and ordered a header from Carpy, Steve was good to deal with but had to call as I was having no luck with email, can’t wait to get it. Received my side badges from Greenjeans , very nice.

I finally fixed the frame damage as 1 of the lower tubes was basically paper from internal rust, I couldn’t find seamless tubing that was a size match so I just cut out the bad sections and welded in some smaller tubing then filled and ground it. It was a fair amount of work but turned out well. After bead blasting the frame I noticed a couple small spots that will need to be repaired, and I want to weld up the headstock down tubes as they’re only slide fit and tack welded. I’m going to make up the removable top tubes at work.

I decided on orange as the main color, what shade I don’t know yet, but this now allows me to go with some custom gold color pieces. After some research on materials I went with aluminum bronze as it polishes up to a nice gold color, resists tarnishing in the elements and has a pretty high tensile strength, a lot higher than aircraft aluminum. So right now I’m making up the fork caps and top nut for the triple tree, will post some pics of the progress so far.

I tried out the Glisten PC on a scrap piece of polished aluminum and adhesion and hardness are not going to be an issue, you can’t scratch it off with a screwdriver. The only issue is it slightly hazes the polished mirror finish, but is much better than any other clear I’ve seen even though I just brushed it on. I think if you didn’t have the side by side comparison you’ be hard pressed to tell if it was cleared or not. I’m going to try it out on a larger piece but I’ll do it complete and spray it on this time so more to come on results. Ciao for now.

[solo 2]

Well it’s been a long busy summer and fall and I’m back to the Cb with a vengeance. I’ve finalized my color scheme and have purchased a few new parts along the way.I’m waiting on the stuff for my dual front disc set up, still have to buy lines and a M/C.. I’ve ordered a set of FZR600 flatslide CVs to play with, I think it might be a good mod, get the best of both worlds with them. The throttle response is supposed to be great, it’s a popular mod with the GS crowd. Right now I’m working on the gauges, going to put in the faces from Lecram, very nice units in KPH. I picked up an F tank, not sure which one I want to use yet or whether to go with a custom bronze fuel cap or an aircraft type.

I’ve been doing a lot of motor stuff in the last couple of weeks, but I think I need to get a roller built to really see where I’m going with this thing. This weekend I think I’m going. to build up some foam for the seat mould. I have to fabricate or buy some rearsets still, I like the Ekert set up, It would be reasonably easy to make.

Lots of work and $$$ ahead, my plan is to have this thing ready to be shown at the Ponoka motorcycle show in July. That was my plan for this year but you know how that goes, I also have a couple of 2 stroke Yamahas that I’m doing too. I think by the time I’m done buying parts and deciding on how things are going to look I’ll have enough parts to build another CB, that’s how it went with the 2 strokes.Sorry if this is all over the place but a lot is happening and I’m not big on typing, but it’ll get more orderly with pics as I go now.

I always thought it was kinda corny to give a name to a vehicle, but when the movie Warhorse was announced I thought “perfect”. What better name for an old, abused and neglected survivor being restored to it’s former glory. So welcome once again to “Project Warhorse”

[Emokid]

Looking and sounding good so far  will follow this .
For rearsets you might want to check out this guys product :
http://oldschoolspeed.blogspot.com/

[jiggliemon]

I'd like a set of those fork caps.
Do you think you'd like to make some?

[solo 2]

I might end up making some more, but they wouldn't be cheap. Aluminum bronze is fairly expensive, plus machining. I'd really have to work out what it would cost, more= cheaper also. I might also be doing a custom bronze gas cap with a weld in bung.

[lucky]

After getting the bike home I started taking it apart and doing an inventory of good parts and things that had to be rebuilt or replaced. In my haste I hadn’t really paid a lot of attention where I should have. The hand switches on both sides were beyond repair, carbs were full of white rust and only good for a few parts, fork tubes were scratched badly, stator cover was gouged from a previous fall, swing arm had about an 1/8” of play, calliper piston is seized, the fuel tank was just that and nothing else on it and finally the frame has a crack in it which oddly runs lengthways down the bottom frame tube under the engine. This was only some of the stuff I had planned on reusing.

So here is an inventory of stuff I’ve acquired since November when I picked up the bike:

JE 836 piston kit
Dynoman DP315 cam
K1 carb set complete
NOS hand controls
CycleX fork tubes
Progressive suspension springs
Fork seals
Tapered headstock bearings
Gas cap assembly
Petcock
Swingarm shaft
Frame grommets
Carb gasket sets

The bike is now totally apart except for the engine which I’m going to leave until some of the smaller assemblies are completed. All bearings and bushings will be replaced and more engine parts to come once I start that. The next big purchase will be a set of Akront shouldered rims and stainless spokes (I’m still screwing up the courage to pull the trigger on that one). The exhaust I’m still waiting on to see which direction I’m going to go, I’m leaning toward a 2-1 system right now.

As for the color I change my mind daily right now, but I keep coming back to the original Flake Orange with original color striping but different pattern as I’m putting knee dents in the tank. Possibly silver which I’ve always thought made anything look sportier. Maybe gold…

I’ll be posting pics as I go and will probably be asking for help/advice along the way, I’m hoping the Hondaman book will go a long way on this project. Ciao for now.

Condition sounds normal.
That "white rust" is aluminum hydrochlorate and it just needs to be cleaned and spray with WD40.

[solo 2]

Not when most of the floatbowl inards are disolved away

[solo 2]

I've been working on getting some of the painting done on the bike this week, I'm using POR-15 Chassis Coat for the frame and brake parts. I hope their clear coat works just as good, stuff is amazing. I'm shooting it using a touch up gun, thinned 10%, 25PSI at inlet. Used very little to do both calipers,M/C, swingarm and lower triple. There is almost no overspray and it self levels beautifully. I need to experiment a little more with thickness and second coat. I basically did 1 full cover coat and then a second after about 10 minutes, I thought I pooched it when the second coat went all rough but it just levelled out in no time.

[solo 2]

Here's my refinished gauges, thanks to Lecram for a great product

[solo 2]

I've just been doing some polishing lately and am still looking at clearcoating the finished parts but I've run into some issues with the prep to make the paint stick, as usual will let you know the results when I'm finished. The Por-15 experiment is ongoing and I've learned alot of don'ts so far, You must follow the prep to a tee or else failure is immenent.

I tried contacting the guy with the speedo adapters to no avail, so I just made my own. I made mine out of 316 stainless as I think the wear on aluminum will be pretty quick with the seal, maybe not but it makes me feel better.

I blasted my F tank and made patch panels so that I can put a bung and cap into it, going to make a custom brass cap for it. I'm thinking of smoothing the top of the tank so there is no ridge in it, there's alot of dents to fill anyway and then I can put my striping on straight with no taper.

I got my Tomesselli Condor bars in this week, expensive but very nice and period correct for what it's worth

Ciao for now.

[solo 2]

Just been doing some bodywork on the F tank so it's ready to paint, smoothed out the whole tank, took some pictures of both tanks. The stock tank has knee indents that need to be finished and its been por-15 coated inside, I bought new cap assembly and petcock but decided not to use it. I'm waiting for the monza cap for the F so I can make a spigot for it. I'm just preparing everything for paint. I have to make myself a gordon frame kit before I do the frame and some swing arm bushings too.

Bought another bike so that kinda slowed down my progress, but back at'er this week.

[solo 2]

Wow, Feb. was my last post, doesn't seem like that much time has passed. I kinda got side tracked with another build, a ground up on one of my 350LC's...



So now it's back at the 750, thinking next spring now, but I've been collecting some more parts and am now in the process of making a plug for my own seat design as I'm not really fond of the generic looking seats available. I wanted something that would extend/compliment the line of the smoothed out F tank as well as fill the hole at the back. This has been alot of work so far as I want the plug to be as perfect as possible so the part will need no finishing other than paint. I formed this out of pink styrofoam insulation coated with body filler. After priming it tonight you notice all the little flaws that still need attention, oh well, hopefully the time invested will be worth the end product.

[solo 2]

It seems that every time I turn around another few months have gone by. Most of my time this summer/fall has been playing with my fiberglass mold, it was a ton of work, time and money. The end result of the mold is excellent though, hopefully I can sell a few of these seats if people like them to recoup my investment, it was good experience anyway. Now I have to buy the proper gel coat and resin to make the actual seat.  This will hopefully be done by the end of this month.


I got my rims laced up and the look awesome, just need to do the final truing and tightening.


Finally got my forks together,  I think the tree looks great with the bronze caps.



My cylinders are in getting bored right now, I tried the Duplicolor engine paint on the them and cured it in the BBQ at 350 degrees, worked like a charm, really cures the paint well. I still need to buy all the parts for the head and I’m considering buying some super rods, too much money in this thing to chance a broken rod. If I keep changing my mind after buying parts I’ll be able to build another bike.
I had to buy a new frame as the old one was just too rotten on the lower frame rails, luckily the salvage yard here is owned by a CB750 fanatic. I had to check 4 frames before I found one that wasn’t rotten.
After doing 2 big builds in the last couple of years I’m going to get a roller started before painting the frame just in case I want to make any changes to it. I’m thinking of making a set of custom rear sets and will probably weld bungs to the frame to place them. Hopefully seeing how it looks will save some time in the end with any major changes.

I've been playing around with POR-15 products and while the ressults look great and seem to be very wear resistant, it still lifts with chemicals,especially brake fluid. It also is very labor intensive an has to be prepped exactly to work, so I bought myself a powder coating gun...more on that to come.