Topic: 1978 CB 750 F Cafe Project R.L.H.

[flaherty500]

Hi Everyone,

My name is Matt and I live near Boulder Colorado. It seems that I forgot to introduce myself before now so, I would like to take this opportunity to tell y'all about my first "Cafe" project

For reasons I can not remember I decided I needed an old school café racer motorcycle. Since it is a popular platform, I chose the Honda CB750 as a donor bike. I looked at Steve “Carpy” Carpenter’s site for a long time and, since he makes such sweet bikes, that is probably where it all really started.

Several months later, the hooks are set in and I’m looking at a pile of bits that should be a bad ass ton up machine one day.

After combing through Craig’s List I located what appeared to be a great starting point. In November 2009 I ended up trading a SIG-228 9mm pistol for a 1978 CB750 Super Sport.

I have been recording several of the steps along the way and I won't bore you with the description until I can successfully load images. Rest assured I have several months and several pics to share with you very soon.

Anyway, thanks for having me on this forum, I look forward to chatting with y'all again.

[flaherty500]

Oh yeah, here I am working on a bobbed 650... before all this cafe stuff got it's way into my brain.

[traveler]

looks good. 

Welcome to the board.

Any questions or help please feel free to ask!

On the Dunstall tank....don't sweat it too bad...what's done is done.  Just figure out how to get it on there correctly and press forward.

I also have a Harley, BTW.

~joe

[flaherty500]

So here is my 78 Super Sport before I took possession, they guy I bought it from was nice enough to drop it off at a local shop for a once over.





The diagnosis of the machine went from better to bad to worse. OK, all is not lost I still have a lot of good parts here and since I’m only into the bike for about $450 I feel pretty good. The next thing to do is get the rusting Leaking Hulk back to my house and get started. I stored the Rusting Leaking Hulk (R.L.H.) in a friends garage while it rusted and leaked for the next week. I still need to clean that up!



Well the next responsible thing to do was to get the title in my name. Naturally, I didn’t do that right away. I did, however, get the ball rolling. I needed to have a VIN Inspection performed by a local dealer first. This was pretty straight forward, borrow a trailer load up the R.L.H. and have them look at the thing.

[flaherty500]

Thanks Joe,

I think somewhere along the road people figured I have modified the tank, actually it's the same today as the day I got it.

I'm guessing that Carpy will make it right, just wondered if anyone else had a similar story.

[traveler]

Carpy is a good guy.....if you return it to him in the same shape he sent it...he'll make it right.

Yes...I was under the impression you had removed the trangle bracket under the tank and were fabbing up new mounts....you haven't....so no worries....jsut give Carpy a call in the morning.

Just my .02

P.S. Carpy IS a member of this forum.....kinda lurks...don't hear from him much.

~Joe

[flaherty500]

My trusty friend Robert and I had originally planned on using a dirt bike cradle to move the motorbike… Of course, that would not have worked. Our friend Justin said his father-in-law had a trailer we could use, he even offered to help out. Since Justin has moved bikes before and since he is generally a good guy we agreed.

Here is Robert acting out for the camera.

When you borrow a trailer don’t be too surprised if you are asked to help out around the house when you get back. Justin’s in-laws were in the process of moving when we brought the loaner back and Robert and I were roped into some manual labor before we could sneak out.

[flaherty500]

I waited until December to apply for the new title and a few weeks later I got the new Colorado title in my name. It was relatively painless even though the original title was from Missouri and I was told that I would need to jump through all sorts of hoops to get this and that it was more trouble than it would be worth.

It’s a good thing I have an epoxy floor, the R.L.H. didn’t get that name for nothing. See, I had no idea that the engine seals were is such bad shape. I put a disposable turkey roasting pan under it at my house but the disassembly process leaked fluids pretty much all over the place. I’m not going to say it was limited to just oil, especially since what was in it when I got it could hardly be called “oil”.

[flaherty500]

Robert and I decide to start up the beast and see if we can figure out what we are working with. Since the OEM gas tank isn’t exactly ready to put fuel in I decide that I need a temporary tank. This isn’t the easiest thing in the Denver Metro area to locate. I found a source on e-bay but I didn’t want to wait that long for something I could surly build myself.

We scoured the Home Depot and decided that the 1 gallon paint can, should be the ideal vessel. Using one of those red, plastic gas containers may have been good too but since the openings are so small we couldn’t figure out a way to thread in the barbed pieces.

A few holes, a few fittings, a few washers and a lot of JB weld and we were in business. We included an in-line filter and a valve and hoped for the best. Oh yeah, we had a fire extinguisher… just in case. The handle worked well as an attachment point to tie the temporary tank to the rafters, gravity did the rest of the work and we left the lid off in since we did not include an over flow tube.

Seriously, if you can’t make a temporary fuel tank you probably have no business attempting to build a custom motorcycle.

[Ecosse]

just wanna say welcome to the community.

your oil look perdy. 

[flaherty500]

A new battery and some fuel and the RLH begrudgingly kicks over. We added some BG oil treatment goop and ran it per the instructions.

If there is one thing that I like... it's a burn up on my bike?


Still smoking like crazy, Robert and I agree…Why don’t we start by doing everything that isn’t the engine? The current goal is to do all the other parts first and have someone re-build the engine for the RLH or maybe buy one that is ready to bolt it? I started to disassemble the bike taking pictures as I went.

[flaherty500]

The Honda SS fuel tank isn’t so bad. The real surprise is that the bio-degradable rust eliminator “Evapo-rust” works as well as it does.


Locating a gallon was the tricky part. Then my wife discovers that it is for sale at Harbor Freight. I’m sure I’ll have an opportunity to use this product again and I will do so with out hesitation. So, back to the tank. I pored 1.5 gallons into the SS tank and let it sit for a long weekend rotating every so often until all the metal inside looked fresh.

Unfortunately when I went to remover the tank badges I poked a hole in the port side!
This, the large dent in the rear as well as the cost to re-paint the thing got me to thinking. No matter what I do this will always be an old tank. I’m also not to sure that the SS style is what I’m going for. I knew I needed a seat and Clubman bars and after several conversations with Carpy I decided to by a new tank, more on that later.

My plan is to use the SS tank as a donor for paint practice. You see I could buy a spray rig for less than the cost of a single tank paint job. Since my wife has a paint project or two I’m going to do it myself. I’ll see about knee dents, for the fun of it, and checkered decals too. Who knows maybe I’ll sell it on e-bay?

As soon as I begun the “Everything but the Engine” plan things actually got pretty fun. I started the disassembly phase of the project with the RLH on the center stand. The seat and the tank were already off the bike so the first thing I did was remove the wiring harness in as few pieces as possible. My plan is to build a new harness by reverse engineering the old one.

[flaherty500]

Since I am planning on rebuilding the engine it has to come out. Robert and I discovered that it was far easier to lay the bike on its side and remove the frame by wiggling it off of the engine.

I did learn a few things about my project bike during the disassembly process. I was told  that my carburetors were from a 1975 engine, it turns out that the entire engine is from a 75. I also do not believe that the carbs were cleaned by the guys at my local shop. Even though they said they had been.Lots of crud and crap still in the unit and there is no way they were off the intake boots in the last several years as they were so hard and stubborn I broke two broom stick trying to get them off.

[flaherty500]

I suspect that at some point in the last 32 years my bike was part of a Frankenstein experiment. You know the kind… Someone had a 78with a good motor but a bad everything else and 75 with a bad motor but a good everything else. They assembled one bike that is still running and sold me the other one. I don’t think PO did this but I do think he figured it out before he sold the bike.




I’ll need to fit all the new parts and in order to do that I’ll need to have them in my hot little hands. I called Carpy and ordered a new Vincent Seat, Dunstall Tank and set of Clubman bars. He also had a Comstar front wheel and since mine has some dents, I bought that too.  Steve is a very cool guy and all those stories you hear about how he lives and breaths café bikes are true. He said he would throw in some decals for my tank and seat too. I like talking to the guy, you kind of feel like he is an old friend, with a thick accent; you almost have to remind him that you want to buy something. He is a bass player too and we chatted about bass cabinets and the Yamaha amp that Mike Dirnt from Green Day gave him. Here is a picture of me and my Dan Armstrong.

[Little_Horse]

enjoying the build keep it coming

[flaherty500]

The Trouble with Engines

As I was saying my frame is a 78F and my engine is a 75 K or F? I learned that any SOHC from 1969 to 1978 will fit in any CB750 frame from 1969 to 1978. My engine did start and it did run, just not well. The guys at, the still unnamed local shop, were tasked with checking out the engine. On a Wednesday I dropped the bike off and they told me it had a sized piston and explained the situation and gave me some options, we pressed forward. On Thursday they said everything looked good and we had 112 compression on each cylinder. On Friday they said the engine was shot! Well you don’t have to look at the manual to long to be confused by that.

Here is my 75 engine ready for... well, I know I said that I was going to do everything but the engine before but you know how these things can get away from you.


I knew the engine needed work but where to start. The option of paying someone to build me a new power plant sounded pretty good. Prices ranged from $1500 to 4K for a gone through motor.

I began considering the possibility of locating a bike with a good motor and less than great everything else. I talked with a guy in Pueblo who had a few machines with sound engines but no title, one of them could be perfect.

[flaherty500]

1-18-2010
MLK Day

Robert and I drove to Pueblo this morning to have a look at an engine and no title frame.  The seller, Tom, had lots of motorcycles in his garage. His rafters were full of junk that he hit with his head every few minutes. His hobby is really more of an addiction.

We tried to start the bike but it only turned over a few times and would not continue to run. Maybe it was just cold or maybe it needs more work? Tom attempted to fill the fuel tank and ended up poured gasoline all over everything. Carb cleaners were used as starting fluid… with no luck. He kicked the hell out of the thing but nothing seemed to work. We even noticed at one point that the kill switch was engaged but the beast wouldn’t cooperate.

After a few minutes of this Tom said that he had an engine that was just sitting in the corner and I was welcome to take it with me for nothing!

I am now one crappy engine richer. I’m assuming it will not run as it will not kick over but it looks a lot better than my 75. Coincidentally this new freebee is a 75 too. If nothing else the alternator cover is better than mine, all was not lost.

This engine’s SR# is CB750E-2390xxx and the one I had before is CB750E-2385xxx that means that the two are only 5258 pieces apart, unless I don’t understand the codes.

The trouble with engines has less to do with the engines and more to do with the people that build and repair them. No one but the guys at my local shop thought that the engine was in such bad shape that it could not be resurrected. As the engine gets disassembled the diagnosis changes.

After my new mechanic had a good look at my engine he found the following

1. Engine is in really good condition internally.
2. Heads and pistons are almost in perfect condition...however...
3. Engine had water all up inside it...needs deep cleaning
4. Oil pick-up screen was dirty and mostly blocked...likely the reason for engine "noise"
5. Cam parts showing wear:  rockers, rollers and chain.
6. Sprocket needs replacement

The R.L.H. engine will need a new one of these and a decent cleaning, at least.

 
I really thought that I’d seen the last of this oily, cruddy, brown crap, yet here we are.

Not too bad, I think I’ll look into a Cycle Exchange alternator though.

The oil screen, even if it’s not the reason for the noise, smoke and gremlins it ain’t right!

[flaherty500]

So, all of this winter's projects have taken up quite a bit of time. I have been finishing up finishing up work in the garage, the wife wanted a climbing wall. Of course,I'm still going to work on Bikes there...



Tons of guitar projects, and all the assorted home renovations that come with a "fixer-upper" and that damn dog too.



While the engine is being rebuilt I did a few little frame mods to fit the tank and seat.




you can see where the bracket under the tank had to be removed to accommodate the Dunstall style tank, remember, that's how this whole thing started.

While I was at it I figured I could remove some of the other tabs that wouldn't be needed.

Next stop, Craig Brown welding up the arse end.

[traveler]

Are the engine pics the free motor, or the original one?

Looks like you're making significant progress.

Really looks, good Matt.

I suggest since you have the motor that far down, to just rebuild it.....paint the cases, cylinders, and  head and bake the paint on and re-assemble.

If you want some power, I suggest Mike~"MReick" on here.....have him do your cylinder head.....unleash some of the hidden power in the head.....even if you stay at 750cc...the power is in the head and cam selection.  Of course, you will have to re-jet, but you will hate yourself later that you didn't do the head up while it was apart, IMHO.

~Joe

[flaherty500]

Joe,

Thanks for the kind words.

Great minds think alike, and ours do too. The engine is, in fact, being rebuilt. Even as we speak my new mechanic has all the new parts and is going to rebuild, refinish and reassemble.

I hope that you don't get the wrong idea about progress... I'm actually running out of pictures and updates  

Oh yeah, that's the original motor. Well, the 75 motor that came with the bike, anyway.

I think I lucked out by not having a 78 motor with my 78 frame. I don't know what will happen with the free 4 cylinder.

Still waiting to hear back from Carpy about the tank. If I decide to change the tank I may change the seat too?

I should have some more news when I pick up my frame from Brown's. a bit more cutting and then, hopefully some mock up.

[flaherty500]

Hey y'all,

I picked up my frame from Brown's Welding this afternoon... Craig Brown is one of my new favorite people, I dropped it off the other day with a vague description of what I wanted, he gave me a price and told me when I could pick it up. It was exactly what I wanted, same price done on time, a good guy to work with.

Here is my frame with the ass end sorted out.



The idea is that I'll be able to mount things to the flat section.





Here is what it will look like with the seat... you will have to use your imagination.

[Ecosse]

that tank and seat?

sweeeet.

[flaherty500]

So here is why this all started... not the R.L.H. project but the posting it on line part. Actually that is a good thing since it has encouraged me to keep moving forward.

Anyway, here is Carpy's "Dunstall" style tank on my frame.

This is what it would look like if I were to, simply, extend the tank mounting rubber nubs in the front.
You can dig how much of an extension that would take...





Now check out the angle of the tank...



If worse comes to worse, and I have to use it as is I'll probably relocate the front locating pins and extent them it would probably look a little like this...

[flaherty500]

Thanks Ecosse,

Should be cool once I got a roller.

Oh yeah, I got to do a little grinding after work today too. I got rid of the rest of the center stand mounts. You would never see them but I'd have known they were there.

[Ecosse]

regarding the tank mock up:

"that ain't right."

what is your plan 'b' if you don't alter the tank mount?

has carpy finally gotten back to you?



btw: every garage should have its own fire hydrant.