Author Topic: Updated 4/26 - What have I gotten myself into or Project Velvet Underpants  (Read 8138 times)

0 Members and 1 Guest are viewing this topic.

Offline mcuozzo

  • Hot Shot
  • ***
  • Posts: 311
  • Bottle in front of me or frontal labotomy?
    • 77 CB750K - needs total rebuild
Okay, after searching craigslist I now own:

77 750K - parts bike - bad engine, rusted out exhaust, no title

78 750K - Frame - nothing else, but it has a title!  (A NJ title none the less!)

78 750F -  parts bike - bad engine, partial exhaust, no title.

So my plan was to take the engine from the 77 and fix it.  If it's too bad (ie too much $$$) I'd try to fix the 78 engine.

I'd like to use the Front end and the swingarm from the 78F.

Here are my initial questions:

Any advantage to using the F motor?  Any disadvantages?

Swapping the front end seems straightforward.  Are there any things to watch out for?

Swapping the rear swingarm seems more difficult.  There is extra tubing on the K Frame to mount the exhaust too.  Does this need to be removed to use the 78F swingarm on the 78K frame?

Conversely the 78F frame has some brackets for the brake line and reservoir.  Am I correct in assuming these need to be added to the K Frame???  Also I want to use a 4-4 exhaust so I'm guessing I need to fab up a rear mount as well? 

Can the rearsets from the 78F be moved over to the 78K frame?  Will the rearsets and a 4-4 cause a problemo???

And what about the wheels.  Obviously I can use the 78F wheels (comstars?) pretty easily.  Can I use the 77K spoke wheels and move the dual front disks over?  And what about the rear disk? 

Those are my initial questions.  Again I'm just going from the pics I have since its too damn cold to go into my workshop (or more accurately I'm too cheap to heat it up for an hours worth of work!!!).  These weekend will be warmer, relatively, so I might start digging into the project and answer a few questions.

Any advice is helpful and yes I did search on these issues but I'm looking for any more recent experiences\ideas.

Here are my blurry picks of the two bikes.  No pics of the frame, we all know what they look like!

Thanks for any help and if all goes well, I'll have some extra parts to sell come summer time!!!





« Last Edit: April 26, 2009, 02:31:08 PM by mcuozzo »

Offline A Grove

  • Some people call me a
  • Hot Shot
  • ***
  • Posts: 300
Re: What have I gotten myself into or Project Velvet Underpants
« Reply #1 on: January 21, 2009, 07:49:44 PM »
I've heard that K motors take better to high-miles and mods... But that may be false information. 

Offline mcuozzo

  • Hot Shot
  • ***
  • Posts: 311
  • Bottle in front of me or frontal labotomy?
    • 77 CB750K - needs total rebuild
Re: Updates with pics - Project Velvet Underpants
« Reply #2 on: January 31, 2009, 09:26:12 PM »
So armed with some advice from forum members I was able to get my 77 engine to rotate freely.  Thanks guys!

Now I think I'm gonna rebuild the carbs, test the electrics and compression and see if I can get it to fire and run a little.  That way when I take out the engine to to freshen it up and transplant it, I'll know that if it doesn't run it's something I screwed up!

I tore the bike down a little to get an idea about retrofitting an earlier tank (needs work!) and making a cafe seat.

-airbox removed
-carbs removed
-4 into 4 exhaust removed (totally rusted out unfortunately)
-tank and seat removed
-rear fender, turn signals and brake light removed.

Here are some pics of the engine and a pic of the bike with the new (old) tank.






Offline KB02

  • Take it easy there, Sonny, I'm an
  • Old Timer
  • ******
  • Posts: 3,760
Re: Updated - What have I gotten myself into or Project Velvet Underpants
« Reply #3 on: February 01, 2009, 06:53:14 AM »
If you don't end up using that F swingarm pivot bolt, I'll be happy to take it off of your hands. :)
1978 CB750K Project
2000 Ducati ST2
...and a pedal bike

Join the AMA today!!

My project thread Part I: K8 Project "Parts Bike"
My project thread Part II: Finishing (yeah, right) touches on Project "Parts Bike"

Offline mcuozzo

  • Hot Shot
  • ***
  • Posts: 311
  • Bottle in front of me or frontal labotomy?
    • 77 CB750K - needs total rebuild
Re: Updated - What have I gotten myself into or Project Velvet Underpants
« Reply #4 on: February 01, 2009, 08:58:50 AM »
Thanks for the vote of confidence KB02!  Just kidding.

As of right now I plan on using it, but if I don't use it, it's yours.   I hope to swap that swingarm over to my 78K frame.  Gotta figure out what needs to be ground off of and welded onto the K frame to make it work.

Watch this space for updates...

Offline mcuozzo

  • Hot Shot
  • ***
  • Posts: 311
  • Bottle in front of me or frontal labotomy?
    • 77 CB750K - needs total rebuild
Re: Updated - What have I gotten myself into or Project Velvet Underpants
« Reply #5 on: April 26, 2009, 02:25:33 PM »
Ok, after a long delay, some progress.

With a trusty assistant I was able to remove the engine from the frame.  We almost came to blows, but it got done!  At one point he wouldn't believe you could get the engine out by lifting the frame off of it. 

The engine is pretty beat, but the top end looks good.  I know I got some build up on the exhaust side, so we'll see what we find.

Is the next step to remove the head and see what the pistons, valves and combustion camber look like???

Let me know what you guys think...

Offline kghost

  • Really Old Timer ...
  • *******
  • Posts: 6,855
  • www.facebook.com/RetroMecanicaAustralia



Here are my initial questions:

Any advantage to using the F motor?  NoAny disadvantages?Yes

Swapping the front end seems straightforward.  Are there any things to watch out for?

Swapping the rear swingarm seems more difficult.  There is extra tubing on the K Frame to mount the exhaust too.  Does this need to be removed to use the 78F swingarm on the 78K frame? No

Conversely the 78F frame has some brackets for the brake line and reservoir.  Am I correct in assuming these need to be added to the K Frame???  Also I want to use a 4-4 exhaust so I'm guessing I need to fab up a rear mount as well? 

Can the rearsets from the 78F be moved over to the 78K frame?  Will the rearsets and a 4-4 cause a problemo???

And what about the wheels.  Obviously I can use the 78F wheels (comstars?) pretty easily.  Can I use the 77K spoke wheels and move the dual front disks over? No And what about the rear disk?  no

Those are my initial questions.  Again I'm just going from the pics I have since its too damn cold to go into my workshop (or more accurately I'm too cheap to heat it up for an hours worth of work!!!).  These weekend will be warmer, relatively, so I might start digging into the project and answer a few questions.

Any advice is helpful and yes I did search on these issues but I'm looking for any more recent experiences\ideas.

Here are my blurry picks of the two bikes.  No pics of the frame, we all know what they look like!

Thanks for any help and if all goes well, I'll have some extra parts to sell come summer time!!!



All the above answers based on a 77 K / F swap.

F motor's have less Hi Po parts and are known for valve guide wear.

Rotor's on the Comstar wheels have a different bolt pattern and caliper mount then the spoked wheels.

« Last Edit: April 26, 2009, 02:39:52 PM by kghost »
Stranger in a strange land

Offline mcuozzo

  • Hot Shot
  • ***
  • Posts: 311
  • Bottle in front of me or frontal labotomy?
    • 77 CB750K - needs total rebuild
Thanks KG, but I think my plans have changed.  I acquired a second 78 750 K frame with a title, so for my first project I'm going to be a little less ambitious and just move all the stuff from the 77K over to the 78K frame (since it has a title).  I'll do some custom parts like the seat, tank and powder coating, but not going to tackle the swingarm and fork swap from the 750 F, even though it doesn't look that bad at all.  I'll leave that for my second project.  Although I'm not excited about the comstars. 

What's the easiest way to get spoke wheels and dual front and single rear discs?  A gl1000 swap of frontends?  What about the rears?


Offline Johnny5

  • Master
  • *****
  • Posts: 1,593
    • CB350F build thread
Nice job getting that engine out of the frame.

Now it's time to check for valve leaks, check the cylinder walls and if all is well, give her a quick hone and re-ring.

Looking forward to seeing your progress.
www.kerosenecycles.com
1971 CB350
1973 CB350F
2006 Harley Springer Classic

Offline MosquitoJones

  • how do i ried biek? and how did I become an
  • Enthusiast
  • **
  • Posts: 134
Hey, what kind of condition is that F tank in?  If you're not going to use it, I'd take it off your hands.
'82 CB650, 65 CP77 Superhawk in chunks

Offline mcuozzo

  • Hot Shot
  • ***
  • Posts: 311
  • Bottle in front of me or frontal labotomy?
    • 77 CB750K - needs total rebuild
To be honest, I don't know.  Obviously the paint is very tired.  I don't go to my shop every day.  Next time I go I'll check the condition more thoroughly and if I don't forget my stupid camera, I'll snap you a few pics.

Not that I'm 100% sure I'm going to start parting that bike out.  It's the second request for parts that I've gotten though.  I could use some $$$ to work on my current project.

I'll let you know what I find, I'll probably send you a pm as to not muck up this thread too much...

Offline MosquitoJones

  • how do i ried biek? and how did I become an
  • Enthusiast
  • **
  • Posts: 134
That's cool.  I'd be doing my own paint job, so as long as it doesn't have leaks I don't shivagit what the paint looks like.  ;)
'82 CB650, 65 CP77 Superhawk in chunks

Offline A Grove

  • Some people call me a
  • Hot Shot
  • ***
  • Posts: 300
mcuozzo - I am not trying to ruin anyones hopes of aquiring parts. but I was given the advice when I started my current cafe' (with two full bikes to work with mine you) that I should keep every single part until I was one hundred percent DONE.  Let me tell you, this was GREAT advice.  It has saved me at least 3 times now.  From oil pressure switches to temporary chains/sprockets just to get to go for a ride on the weekend to having working carbs.  That is my advice to you as well.

Offline mcuozzo

  • Hot Shot
  • ***
  • Posts: 311
  • Bottle in front of me or frontal labotomy?
    • 77 CB750K - needs total rebuild
I here you.  But the tank I could part with.  You see I acquired a few tanks here and there (4 spare early 750 tanks, plus my K tank, plus my F tank) so I'm not really gonna miss one tank.

Now parting with the swingarm bolt, I'm gonna wait on precisely for the reasons you mention.  Good advice.

I've gotten a few pm's for parts also but I wasn't able to help out because mine are broken too.  The F bike was laid down so some stuff is beyond help.

Until I finish one bike I'm going to hold on to as much as I can.  For example I have a nice aftermarket stock looking type seat (travelcade I think).  I could sell it but I might need it for some test rides before I finish my custom seat (if I ever do!).

Matt


Offline Flying J

  • Old Timer
  • ******
  • Posts: 3,386
if you strip the motor down you could use the F bottom and the K top. The F top can have early failure due to valves but the bottom end is supposed to be stronger then the K