'81 CB750C "Rock-It" (X-Basket Case)

[Hoosier Daddy]

 A couple weeks ago I posted about my luck using "Freecycle.org" in finding a titled DOHC 750 frame and a few bit's-n-pieces for FREE. http://www.dotheton.com/forum/index.php?topic=34348
At the time the guy commented on having the diassembled engine, forks and wheels over at his Dads and if I was interested in those he would sell it all for $50.
This week he e-mailed me that he had it at his place and I headed over with low expectations. After all, he had the bike for only a parts donor.... SURPRISE!
 

 



 

 
This thing is in GREAT shape! The only major parts I don't have are the the side covers, tank, and rear shocks. Maybe I misunderstood and  the shocks are what his Dads bike needed instead of the front fork. After a quick once over last night of everything so far, for the life of me other than him saying he was just going to "freshen up" the engine to use in a sand buggy, I don't know why anyone would dismantle a low milage engine in such good condition. Cams show no wear, you can still see the hone marks on the cylinders, super light scuffing on the piston skirts. WTF is wrong with people!
I planned on flipping this bike to make some cash, but after seeing it I may have to change my plans. Even though it's a "C" model, after reading a AWESOME post by SoyBoySigh I can see there are lots of options for this Cruiser DOHC.
So for now...Let the fun begin!

[Hoosier Daddy]

Well, I thought I would up-date my Sig to include this build. Since we are limited to the amount of characters I had to do away with one    . Since I sold "Little Sister" my CB350F this spring, she got push out...
 Next came about the thinking of a name for this one... following my past themes... I present to you...
 
ROCK-IT
 

[peteGS]

Nice one HD! How the hell did I miss you starting up a new build? I must be slacking off...


So what's the deal? Another brat style like the GL and GS? Or something different altogether?

[Hoosier Daddy]

Cheers Pete, you didn't miss it but by a couple minutes!
Still a lot of research to do, so right now I am up in the air. This "C" Model is like the "L" of the GS Suzuki's. '80s UJM "cruiser" lineup that was all the rage back then. Seems it would be better suited for a Brat / Bob-job but I sure want to do a CR replica. Probably will save that for the CB450 No Class build that got pushed aside because it is in need of MAJOR work.
 This bike is very similar parts wise to the GL1100 I have, due in no small part to being the same year. I know these carbs and the suspension seems veeeerrry close. Ought to be an easy one, if there is such a thing.

[YogiBear]

the engine looks really clean. it's a great feeling when something like that comes through isn't it? 

[Cafe Redneck]

Looks like you hit the motherlode of a parts bike.
I'll be watching build. After the Miracle you preformed on the Suzuki, should be easy for ya.

[peteGS]

Cheers Pete, you didn't miss it but by a couple minutes!
Still a lot of research to do, so right now I am up in the air. This "C" Model is like the "L" of the GS Suzuki's. '80s UJM "cruiser" lineup that was all the rage back then. Seems it would be better suited for a Brat / Bob-job but I sure want to do a CR replica. Probably will save that for the CB450 No Class build that got pushed aside because it is in need of MAJOR work.
 This bike is very similar parts wise to the GL1100 I have, due in no small part to being the same year. I know these carbs and the suspension seems veeeerrry close. Ought to be an easy one, if there is such a thing.

Haha cool... so if it's like the L, then that means you can cut it all up right? Isn't that the deal? 

[Hoosier Daddy]

Yep!
As we know, "L's feel no pain when you cut them up"... so I bet C's have the same gene.

[peteGS]

Yep!
As we know, "L's feel no pain when you cut them up"... so I bet C's have the same gene.

Cool! You got a sawzall or whatever it's called? 

[SoyBoySigh]

Ahh, you're too kind. Nice to see the bike you're talking about now. Looks great. And yeah it sound crazy that they tore down the engine. Sometimes people just do that. My former father in commonlaw tore down a great old GS when it was pretty much new, it was sitting in his garage when I met him in '90 and I guess it had sat there for several years already. Should have taken him up on it ha ha, but the deal came with spending the time with the guy putting ti back together. I certainly spent plenty of time working on vehicles with that guy over the next dozen odd years. And odd years they were. As for explaining why he tore it down, it was a "knocking" he'd heard, one he had to listen for with a long screw-driver but still couldn't pin down. But of course, he WAS certifiably crazy and he did later die of a brain tumour.  Okay, not "certifiable", but when he DID go in for a three day assessment, he came out and said to me "They said I'm not crazy, just border-line." Ha ha. That's like something out of a cartoon in some kind of "Psychology Today" magazine. Anyway, just sayin', people tear down engines for all sorts of reasons. Often as not, to prove to themselves that they CAN. And because they don't wanna pay for the labour, which is often ridiculous when you can't actually get a GOOD mechanic in the first place....

But yeah, like you say: all sorts of possibilities.

(((Damn, you were gonna FLIP it? Ugh, that practice is reprehensible. Not at all good for the hobby as a whole. Every good hobby gets big enough that you "Can" make a buck, and it attracts people from all over the place who have no other reason for being there. Happened with pet reptiles in the early nineties, happens time and again with the whole fish-geek thing, you name it it keeps happening, and every time the people who are into something for the sake of the hobby itself are never the better for the services of all of the middle-men who're suddenly in the picture. I swear, every time I bring my bike out into the driveway some prick comes along offering me a hundred bucks here or two hundred bucks there. This year I'm gonna keep an aluminum base-ball bat next to my tool-kit. 'Cause when I walk towards them with my cane it only encourages them to open up with some comment about how I'll "obviously have no more use for a motorcycle" etc etc. Yeah, not when I'm in prison....)))

Ahem. LOTS of possibilities. (Like if you're not gonna fix it, sell it at no profit to some teenager who has the interest and motivation....) *Cough* LOADS of possibilites, yes. Coming from the perspective of working on the '82 CB750F, I'd say you've got some better parts, in terms of the frame's passenger peg bits, that's a nicer looking frame, at least in that area. I don't know for sure whether the 'C engine from that particular year has the spiral type cylinder studs, but if you want a set for that engine I know where you could get a set for cheap, ha ha. I can't tell from the pictures. But yeah, I think these bikes are great for a CR750 replica, not only do I think that's an awesome idea, that's right along the lines of what I was thinking right up until I hit on the idea of making mine look like a sand-cast, or at least a much older UJM. But heck, you look at all of the classic bikes with full bubble fairings, there's no telling what's under the hood. It'd be cool to show up at one of those races with a Gixxer all dressed up in the old fairing and stuff, just blow past all of 'em and they'll all wonder "what was THAT?" ha ha. It's still sad to see a cruiser chopped up. So long as it's not "CHOPPED" however, I am sure it would be grateful. Ha ha. One day, these cruiser type bikes are gonna be trendy again. Just you watch and see. I still owe my mom a million bucks over that bet we made about bell-bottom pants. Or would that be a million for each time they've come back? Ha ha. But looking at the way the DOHC was marketed in North America, I think the Custom models were an extra salt in the wound, of the way they omitted the reark-set pegs and low bars etc from the U.S. market bikes, even on the 1100F, it's weird but I think it followed in the vein of the way that Guzzi marketed their U.S. bikes too. Which wasn't so much an insult direct from the Italians, as it was a suggestion from their distributor, the Berlin Brothers, who went to a Police convention ... one can imagine the scene with the police convention in "Fear And Loathing In Las Vegas" ha ha, here you are representing a company making money off of people SPEEDING, hell it might as well have been a drug thing. But yeah, always the foreign bike people came to North America (not to malign Canada and Mexico etc, but I don't wanna bash Yankees, if only because I've grown tired of it....) but yeah the advice they were given was always "It doesn't NEED to turn any corners. Just make it like a Lazy-Boy reclining chair and you'll sell 'em like hot-cakes" and a result of all of this is that the "Cruiser" bikes were often sold ONLY in the U.S., and by this time I think it was an insult, not just market savvy. Ha ha. Fuck it though, I don't think Europeans know what it's like to ride for ten hours in ONE DIRECTION, if any of them did that they'd have caused a half dozen international incidents. It's nice to be able to carve those canyons and all of that, hell we have that here too. But we also have the great plains. And as a result, some of the fastest riding anywhere. Note that Bonneville Salt Flats is smack dab in the center of all of that? Yeah, not too far from me. And for me, the Cafe ergonomics are actually an attempt to deal with chronic-accute back pain. It sounds counter-intuitive, but most things that actually help with this seem that way at first. If I can stretch my back all of the way forward and put all of my weight on my two blown out separated shoulders with the arthritic bursitis in them, which they still haven't operated on, then my back will feel that much better. Starting to think I need a trike. Or a quad. And a chauffeur....

Ahem. The only part I see as a weird stand out thing about YOUR BIKE is the leading axle forks. But look at all of the old slash-six Beemers, they make some great cafes and they've got shocks with the leading axle. So big deal. First thing you wanna do, is jack up the ass on that thing. And look for a wire-spoke drum hub that will fit that rear shoe plate, maybe something off of a 'K model. Then a '75-'77 GL1000 front wheel, a non-stock foam and cover for the seat, drag bar or club-mans, if you can find a club-man bar that will fit the DOHC triple properly or maybe the 'C model top triple is narrower I dunno, I'm sure the pull-back is different. It's still a nice triple when you polish it up. And then you might wanna trim the fenders down a wee bit but not too much, and then look into fitting a SOHC gas-tank of some sort on it. Some of the GS tanks look good on the custom. Seen 'em on the custom forum and the supersport forum. Thing is, if you did a swing-arm swap and front end swap, your bike could look like any of those "Hyper-Bol-D'Or" or "Super-F" bikes on the 1100F 'F-orum, only BETTER, 'cause it has the frame features I just mentioned. I dunno whether the rake on the neck is any different than the supersports, but if you jack up that ass, get the 18" front wheel happening, and it will tighten up the steering a bit. Or a lot. Ha ha. Pretty sure the 'F shocks are a straight bolt-up with an extra inch or two, but there's gotta be something even better than that, I just don't recall what it is right now. Any which way, best to look for some cool retro after-market shocks, and get them from classifieds on the DOHC sites before you even look at fleabay, there's stuff in there you won't find elsewhere. Or place a want ad even. There are days that I'd trade my 'F frame straight up for a 'K frame or a 'C frame. Gotta spare, and a swinger for it too. But I think I'm gonna find a way that it won't make any difference. I've seen some funny Euro-market 'K models that looked like the frame was sorta like a 'C, sorta like an 'F, I don't know what it's like for them for spare parts. Still, the nice thing about the DOHC is that while you don't see too many cafe bikes, everything else has been done to death with 'em, so there's a load of tech info out there.

-S.

[SoyBoySigh]

Oh, and did you get that membership thing sorted out?

[Hoosier Daddy]

Thanks again for all the suggestions. I copied your previous post in the previous thread to have for quick referance, but having it here is priceless.
 The shape of the "F" tank is really staring to grow on me, cutting the ear lobe off the side would clean it up a lot. I wondered if the '80's GS tank would mate up, the neck width is very similar... but those TSCC "E" model tanks are getting top money. I can pull mine off the GS750 and see if it will fit, OR I am planning on loading the frame (and some trading stock) into the truck and taking it to a nearby motorcycle salvage yard and go through the ROWS of tanks on shelves he has and see what I can come up with
 Here just one pic as an example from last summer, but check out the black one on the middle shelf to the right of the first pic.
 

 
I see a wide tunnel and an "H" logo, plus a boxy shape, at least what I can see.
 
Leading axle... yeah, I got 'em... one more than one bike I might add. The GS has them too. Because it was also a cruiser style "L". I think they were to add the illusion of having more rake but if I remember right, the neck angle is the same as the sport "E".
 

[YogiBear]

I believe the tank you are talking about is a CX500 tank.

[Hoosier Daddy]

Just a little update to let you all know I'm not slackin. Just not making a lot of noticeable progress. A shit-Ton of research trying to decide which way to go on this build.
I found this guys DOHC750 build pic and now it's got me wondering if maybe I posted this build in the wrong section... 
 

 

 
 
So in the mean time I've been cleaning up the engine. I mean, no matter what way I go, this is a given... right? So with some kerosene, scrub brushes, Scotch-brite, then started pulling covers. I am liking how good this one looks inside!
 

 

 
Gave the cylinders a fresh light hone job to break the glaze.
 

 

 
A couple of valves failed their leak test. I filled the combustion chambers with a mixture of kerosene and ATF and even though it held fluid, two of the exhaust and one intake ports were wet on the second day so I am going to have to lap them...
 

 

[YogiBear]

I think that you could make the bike work either way, but that ^ works well with the stock lines