Author Topic: Begining of my first project bike (78 CB750F) (Read 10988 times)

Thor's Hammer! · « **on:** July 29, 2009, 09:19:42 PM »

Picked up my first CB ever tonight

I was initially going to wait and get a more complete CB750, but found one close to me for a decent price ($800) and went to look at it. The frame had been chopped at the back, behind the shock mounts and wouldn't run for more than a minute or so, but the kid who owned swore he rode it from GA to FL. I initially passed on the bike, but offered him $300, expecting him not to accept...I was wrong. I was willing to pay $300 for a running (barely) CB750 with good tires and comstar wheels.

I haven't decided on a theme for the restoration yet and I definitely have a bunch to learn these bikes!!

So far, the fiberglass tank/side covers/tail section bit I am thinking to ditch.

Here's some pics:

Any idea who makes the fiberglass body kit?

Any thing on the bike look odd or out of place?

kevins750 · « **Reply #1 on:** July 29, 2009, 09:41:07 PM »

Looks like it could be a Tracy body kit...google the name and compare some photo's to what you have...

Thor's Hammer! · « **Reply #2 on:** July 29, 2009, 10:54:50 PM »

Thanks Kevin,

I agree it seems similar to some of the Tracy kits...but I can't find one with the tank flares/indentations like mine has.

KB02 · « **Reply #3 on:** July 30, 2009, 03:49:43 AM »

Those are not the stock carbs, either. Could be part of the reason it's not running well.

Thor's Hammer! · « **Reply #4 on:** July 30, 2009, 08:52:11 AM »

Quote from: KB02 on July 30, 2009, 03:49:43 AM

Those are not the stock carbs, either. Could be part of the reason it's not running well.

Hmmm....bummer.

Looking at the below image from a link I found in the carb faq section...it seems they are indeed not the correct ones:

These are the correct ones rights??

And then mine are these:

Anybody know what these carbs are off of??

I will take a better pics today once I get home.

Thor's Hammer! · « **Reply #5 on:** July 30, 2009, 07:46:48 PM »

I think I found my motivation:

The cafe look is nice, but I don't think I would be comfortable on longer rides.

I really like the factory look of this bike and would be proud to have something look close to this nice.

What do you all think?

Flying J · « **Reply #6 on:** July 30, 2009, 10:37:44 PM »

Those carbs look like they might be off a 79+ cb750. The other picture you have is also the wrong set. those are pre 77 k carbs. That tracy looking fiberglass thing might fetch a few pennies on ebay to pay for the parts you need on you restore. there are quite a few guys on here with F bikes. They were the best bikes so were pretty much the cool kids on the forum. Check out the 750F thread and feel free to PM guys with questions. http://forums.sohc4.net/index.php?topic=55178.0

Flying J · « **Reply #7 on:** July 30, 2009, 10:47:27 PM »

also it has fork boots. the F doesnt have fork boots. Its going to be hard to return it to stock with the tail chopped off like that. I have a stock seat for sale but there is a hump that the rear of the seat sits on and yours has been chopped off. I am going to eventually chop mine off to finish up my cafe. i wonder if it could be welded back on?

Thor's Hammer! · « **Reply #8 on:** July 30, 2009, 11:21:32 PM »

HA! Somebody is reading my posts

Thanks for your replies ffjmoore.

Thought maybe folks got tired of me running off at the keyboard. Not too many responses.

I HATE the Tracy kit (if that's what it is)...already posted it in the For Sale thread.

The frame being chopped in the back was one of the things that made me not want to get this bike. For the price i paid, i guess I can't complain though.

The rear frame seems as though it could be welded back...maybe somebody will confirm.

Tomorrow I am gonna pull the carbs and clean them up (rebuild without parts) and see if I can start the bike.

Flying J · « **Reply #9 on:** July 31, 2009, 07:51:10 AM »

You can build a cafe looking bike and keep it comfy too. Just dont put on the rearsets and keep the handlebars raised and you will be pretty good. You could even put the $50 ebay cafe fairing and be even more comfortable with the wind out of your face.

Thor's Hammer! · « **Reply #10 on:** July 31, 2009, 10:51:28 PM »

Well...still can't confirm my motor is a K8 or a F3 model....bigger issue right now is that my carbs are from an early 90's Nighthawk 750

I have no idea if they will flow too much fuel and or air for the SOHC engine, but tomorrow I am going to clean them up (they are VERY dirt) and see if the bike will run for more than a couple mins (aiming for 5-10 mins).

After it runs for a little bit, if I can find an oil filter and plugs locally, I'll do those as well as running some Seafoam thru it.

I'll take some pics along the way...

Wish me luck fellas.

KB02 · « **Reply #11 on:** August 01, 2009, 05:23:12 AM »

Good luck.

It will be interesting t see if those carbs will work. I'm assuming they will, hence they're being on the bike. Or they might not, hence the bike not running well. I think the later model carbs started using vacume, didn't they? might be an issue you run into.

Flying J · « **Reply #12 on:** August 01, 2009, 08:03:42 AM »

Dude, I say keep the tracy body. its going to be a paint to get that thing back to stock. Plus you will get way more looks with the tracy kit. Its so unique. It could be a really cool looking bike.

Haha i found your bike. Looked good in white.
http://dotheton.com/index.php?board=14;topic=7532.0#msg65754.
I may have a stock set of carbs. Look on ebay for a set. Even the older K model carbs should work right.

Thor's Hammer! · « **Reply #13 on:** August 01, 2009, 12:37:38 PM »

Quote from: KB02 on August 01, 2009, 05:23:12 AM

Good luck.

It will be interesting t see if those carbs will work. I'm assuming they will, hence they're being on the bike. Or they might not, hence the bike not running well. I think the later model carbs started using vacume, didn't they? might be an issue you run into.

Thanks KB02!

You're correct! The bike is now running!!! I cleaned the carbs (they were VERY dirty and gummed up)..found the #2 carb had a hole in the diaphragm. Also found that the carbs only work when the pitcock is on prime...no vacuum. Also, even when on prime, the tank can't be at 5 ft as it floods the carbs and gas comes flowing out the vent hole between carbs 1 & 2.

My buddy took some video with his phone and I may post it up. Also took some picks of the carb cleaning process.

If I can identify the carbs, I'll get a rebuild kit.

Thor's Hammer! · « **Reply #14 on:** August 01, 2009, 12:44:01 PM »

Quote from: ffjmoore on August 01, 2009, 08:03:42 AM

Dude, I say keep the tracy body. its going to be a paint to get that thing back to stock. Plus you will get way more looks with the tracy kit. Its so unique. It could be a really cool looking bike.

Haha i found your bike. Looked good in white.
http://dotheton.com/index.php?board=14;topic=7532.0#msg65754.
I may have a stock set of carbs. Look on ebay for a set. Even the older K model carbs should work right.

Dude!

That's awesome...you're correct...that's the photo from craigslist the PO posted...19 year old kid here in Clermont fl.

I am gonna save that pic.

I don't know for sure the body kit is a Tracy or a knock off. It really isn't my thing though. The bike you posted looks nice...but I prefer the cafe look of your bike or even the stock look of the bike I posted above.

I am in discussions with a member who has the big pieces from a 78 750F...we'll see what happens.

Thanks for that link man...that's really awesome man!

Thor's Hammer! · « **Reply #15 on:** August 01, 2009, 07:52:12 PM »

Some pics of the carb clean up:

A forum member has identified the Keihin VE54A carbs as being off Honda Nighthawk CB650SC 83-85. Good to know

I didn't do a rebuild, wouldn't have known what parts to get for mystery carbs!

The carbs were filthy, but after cleanup, I got the bike to run!

Freshly pulled from the bike and sprayed with carb cleaner.

more of the same.

...

Diaphragms, slides and springs out, the number 3 needle was so bad I ran some sandpaper over it...

...

#3 float base had lots of trash in it.

All the floats and bowls and whatever these jets are called pulled.

A shot of the #3 bowl...more trash...

That's it for the pics.

I again sprayed the hell out of the carb bodies, every seat, passage, etc...pulled out the slow jets(?) and cleaned all those too.

Put everything back together and the bike ran pretty good.

KB02 · « **Reply #16 on:** August 02, 2009, 06:10:05 AM »

Sweet. We like it when they run good.

Thor's Hammer! · « **Reply #17 on:** August 04, 2009, 03:37:48 PM »

Couple of updates:

The Tracy body is pending sale.

I have bought a set of carbs correct for the 78 750F along with a headlight bucket, turn signals, turn signal ears, and a set of horns.

Also, not sure I mentioned it here or not, but the tail section of the frame was cut back to just where the rear mounts are and the rear connecting piece is that goes between the frame rails...here is a pic:

I have a lead on these as well...just waiting on confirmation.

Now for the bad news.

I found out today while looking over the bike that the previous owner hacked out the triangular brace that would normally go right in back of where the coils sit...I suspect this happened when they installed the dyna coils...but WTF....I mean really, why would anyone do this??

I know this bracket might not be needed, but I am really wondering if I bought a bad example of the bike I love and hoped to restore to perfection.

Trying to decide what do about this.

Thor's Hammer! · « **Reply #18 on:** August 04, 2009, 06:21:33 PM »

And there is even more bad news.

The seat lock bracket/tab was cut off the frame too....!@#$%!

A stock restore is starting to look out of the question unless I get a welder and learn to weld.

Flying J · « **Reply #19 on:** August 04, 2009, 06:29:24 PM »

clean it up get it running and sell it. Make some cash and find a different bike.

Roach Carver · « **Reply #20 on:** August 04, 2009, 07:38:13 PM »

this is a perfect bike to build into some kind of custom/cafe etc. too many hacked up and missing bits. dont get me wrong, with enough money and time anything is possible, but like said previosly you might ought to just flip it.

kerryb · « **Reply #21 on:** August 05, 2009, 03:02:05 AM »

I have the seat lock tab with lock and key , the rear section from a '78k frame, and some other assorted bits. You can have them for postage. The triangular frame brace dosn't look too hard to make. For those who are cringing about me cutting up a frame, there is no title, and getting a new one in N.Y. dosen't seem possible.

Thor's Hammer! · « **Reply #22 on:** August 05, 2009, 06:48:23 AM »

Thanks KerryB.

That's a really nice offer man. I am still debating what I am going to do just yet.

I am going to look over the frame more closely this weekend after stripping it down further and make certain nothing else has been remove or is missing.

I might take you up on the offer, but let me decide what direction I am going to take first.

Thanks again!

Mike

Thor's Hammer! · « **Reply #23 on:** August 08, 2009, 08:47:36 PM »

Well....decide I am still gonna try for a factory like restore. A professional welder could fix my issues in short order I think.

This is the post from the wanted parts thread showing the needed frame pieces:

http://forums.sohc4.net/index.php?topic=56051.0

Anyway...quick update. Received replacement carbs which need a rebuild along with a few other bits...front turn signals and ears, light housing and duoble horns as came on the bike.

Ordered a replacement EMGO ignition switch (I know these have a short life and will require the "Hondaman" fix to drop voltage at the switch).

Also ordered a bunch of stuff from hdlparts.com. All the carb gaskets, all the caliper seals, front and back master cylinder rebuild parts, and front brake replacement lever...al told close to $300, if indeed they have all the ordered parts...fingers crossed.

Tomorrow I tear down the carbs and possibly the front calipers.

Thor's Hammer! · « **Reply #24 on:** August 09, 2009, 10:46:13 PM »

Pulled the "new" PD carbs apart today. The bodies are really dirty and I'm thinking about grabbing some Yammy carb dip (ACC-CARBC-LE-NR)...I have read a lot of good stuff about this stuff and am hoping it can get these carbs cleaned up.

Also pulled the front calipers off and used the lever and some wood scraps to easy the pistons out nice and slow...work really well...in the past, I have used compressed air and man, that is scary. Didn't want to do the same this time.

My goals this week, assuming I get the parts order:

Adjust vavles
Gap and replace plugs
Get carbs rebuilt.
Bench sync
Install carbs on bike
Start and run the bike for a bit

News:

Author Topic: Begining of my first project bike (78 CB750F) (Read 10988 times)