'81 CB750C "Rock-It"

[Hoosier Daddy]

I just joined and have been knee deep in my 4th bike build. This ones a '81 CB750C I picked up for $50 that was disassembled by the PO who planned to make a sand buggy out of the engine. He let it set for two years in a garage and gave up. This is what I brought home.









A lot of work lay ahead, I am estimating 1/3 way on the resurection and uploading pics into my new photobucket account. I had 1029 pics of this and past builds on Webshots, but it is going Belly-up. So I will be starting fresh here with a build that is already in progress.
So stay tuned, more to come.

[Hoosier Daddy]

 I started out cleaning the frame. He had already cut off the helmet lock tab and there was a couple spots he had used a grinder on the paint that had rusted. So I used my die-grinder with some sanding discs to finish what he started and then hit the factory weld splatter. Then sanded the entire frame. I like to use medium "0" steel wool, it contours to the frame tubes and leaves a surface for the primer to stick to.



Then came 3 cans of self etching primer were applied and left to cure.



Mean while I was searching for a tank. I had read many posts on other forums that the "C" model's frame didn't allow the use of other models tanks well, at least not a direct bolt on. I found one that  was listed on Ebay as a CB900F tank and loved the shape.



The price was within my budget and I figured if it didn't fit, I could clean and paint it and relist it for a profit. Got it delivered and set it on the frame to discover it fit like a glove! I later learned it was actually a "K" model tank because of the emblems where "F" had decals. and buy the size of the petcock (20mm) I am guessing an '82
I stripped it down to bare metal to find 3 layers of paint and bondo... it had a hard life.



Icut the side cover mounting ears off the tank and got 80-90% of the dents out with one of those "Pops-a-Dent / "Ding-King" tools. Don't laugh, I have used it in the past with pretty good success and it never lets me down. A few thin layers of mud to cover the remains and gave the tank some high build primer then sealer.



With everything now in primer, I set the tank in place and used styrofoam to mock up my seat pan. I fiberglass my pans by using the styrofoam as a "buck" instead of a classic "mold". You'll see what I mean when I get there.

[Piute]

    Looking great Hoosier,
                                        like playing in glass myself

[shinyribs]

I love the Members Builds part of this forum ! Looking good so far man! Some nice looking work on that tank! If by chance you need any front end parts I gotta complete 81c front end I wont be using. Looking forward to more on thid one

[Hoosier Daddy]

Thanks for the props! I will try and get you all caught up without loosing too much detail on how I got to where I am today.
Piute: Is that a side cover? I am thinging of making a custom pair out of fiberglass, but I also have some sheet aluminum that might be easier.

shinyribs : Thanks for the offer! I don't think so at this point but may have to later on... good to know.

While the body shop type work was going on, I also started in on the engine. The PO had pulled the head, cylinders and pistons. I inspected and measured everything I could think of per the manual and for the life of me can't figure out WHY he did it. Unles it was just to "freshen" things up.

I used kerosene to give it all a good washing, inside and out. Then a  used a toothbrush and rubbing alcohol on the outside so the Duplicolor engine enamle wout get a good grip.

[Hellbilly429]

While you have it all apart have you checked that charging rotor to make sure it's good? I'm sure you might have but figured I'd give you the head's up since these charging systems (especially the rotors) suck and cost a lot of money. Love your other builds tho, looking forward to seeing this one

[Hoosier Daddy]

  Nothing wrong with a reminder like that, keep 'em comin in case I over look something.
But yes, rotor 3.9 ohms between the slip rings and the stator checks 0.7 between each leg (3 yellow wires), infinite to ground on each.

I put ATF thinned with kerosene in the combustion chambers to check for the vales seating properly, slight moisture grew in various ports overnight.



So after disassembling the head, I used Marvel Mystery Oil and a brass brush to clean the combustion chambers and the intake / exhaust runners. Then lapped the valves by hand to get rid of the slight pitting(ugh!).  But the seats and valve face turned out nice.

Did a quick cylinder hone on the jugs... yes, I know it's not a Hardley and they are called "Cylinders" but I like saying "jugs" ( Freud would have a hay-day in my head... jugs, Jugs, JUGS!)





I found a OEM Honda gasket set "A" on e-bay for less that the dealership wanted for the head gasket alone. Pistons and cylinders miced out withing the service limits so I instailed the base gasket and jugs (there's that word again). Badda-Bing Badda-Boom we are in business.

[rrgunslinger]

Very Cool!

[TOOLS1]

I like "JUGS"
TOOLS

[shinyribs]

You gotta love nice,round jugs.

[Piute]

                         Nothing like a good pair of Jugs
                           Guess we need 2 pair  

[Hoosier Daddy]

 Getting you closer to present day, I scuffed all the primed pices and shot them "arrest me red"...
OK it is actually 2 part catalyst farm implement paint. Massey-Ferguson Red



Let it cure and took the tank out in the sun...




and one of of the frame,



Disassembled the shocks and cleaned them, then started putting it all back together...



More to come, just couldn't wait to get those on here ;)

[Hoko]

Wow, fifty bucks!

[Hoosier Daddy]

 

Hoko wrote

Wow, fifty bucks!

Yeah, "bike in a box"... or at least most of a bike.  
The good news is, what's there is in good shape... Did i mention the milage?

[Half-Caf]

That thing will no doubt be very red. I guess Shiny was right with what he said!

shinyribs wrote

Welcome to the forum. Those are some brave color choices you went with on those bikes!

[shinyribs]

oooh. I love red frames. It just looks...right. Good job on the paint man. It looks nice!Real nice!

[Hoosier Daddy]

  Heh, heh.. yep, she's coming along nicely. Thanks!
The PO had hacked off the mufflers with a sawz-all and left me with just the 4 head-pipes. The Chrome was pitted to the point I couldn't polish it up so I took them to work and sand-blasted them to give some texture. I plan on using black Bar-B-Q paint. I used rustoleums on the Suzuki build and it has held up well.



Then came searching for mufflers. Originally was going to go 4 into 4 because I didn't want the hassle of welding up "Y" pipes to tie each side together for a 4 into 2. But then I found these NOS Mac pieces for $40 "buy-it-now".



 Literally NOS, never been installed! I like their style and I think I can line them up once the engine is in.
I may have to bend some 1 1/2 or 1 3/4 adapters to get the angle right but should look good on the black head-pipes.

[lostson]

 Sweet build you got going here and your previous work is excellent as well! And to add my 2cents I like jugs too

[Hoosier Daddy]

Thanks lostson, it is appreciated!
Now lets see, where did I leave off...
Valves are reinstalled in the head, I need to get the buckets and shims and cams back in just to measure the clearance yet. There's no noticable wear on any pieces but with the lapping I'm sure I changed it some.

I took a look at the triple tree and the PO had done some grinding on on side of the handlebar clamp / fuse holder. was going to repaint them black but when I slid them on the frame it seemed too dark... So with a little stipper and then some scotch-brite, I got these raw bits.



Even though I likes the brushed aluminum look, I decided to spend an afternoon on the buffing wheel. With a new Allballs steering bearing kit and some aluminum paint on the iron lower clamp, it got installed and looked much better to me. Damn hard to get a photo of it without a big bright glare from the flash!



This week I cleaned up the rest of the forks and got them installed with the new Headlight ears. These are Dime City's "Medium Weight" units and are MUCH sturdier than the el-cheapo "universal" ones everybody sells. Very happy with them and highley recomend to anyone watching.
Any-how here is where the front end is today. My appologys if the pic is too big... But Ohhh the detail one that's actually in focus!

[Piute]

     I'm Jealous
  When I see such great prep.work to get a nice finish,Never to much for Quality Work,Makes me wont to start a frame up on my F2 , but no engine work needed yet ,Thats a great thing. This build is more fun then A Man Should Have ...
                                So have the color name right"arrest me red"...