Topic: Another CB750 build here in central PA - 1974 CB750

[BLEAMA]

Hi I 'm Jim...  I have been looking at these pages for sometime as a guest and decided to join and post my project.

Started this journey at the end of last summer...want to be done in May.


Here is the bike as pictured in the EXXy auction:




Here is the listing description:

The frame with title is worth  $250 !

1974 Honda CB750 K4  Semi Survivor - Not Running -  Needs work
17,400 original miles !

Clean PA TITLE !  -Pa is a notary state so title will need to be notarized !

Picked this up from a friend of a friend. He had stored it in his basement since 2009 at that time it was running. Unfortunately he removed the plugs and moisture got into it and the motor is now frozen [I have penetrating fluid in cylinders but its still not turning over. Top end will probably need to be town down.
Gearbox shifts fine, clutch works [releases].
Speedo works.

Has 830cc Big Bore Kit, high compression pistons [not sure what brand].

Missing headlamp and battery.
No tool kit.
No owners manual.
No exhaust system.
RH rear axle spacer missing.
Has a few bent cylinder fins and one broken [see photos]. Fuel tank rubber hold down is bad.

Original paint. Chrome has some rust see photos.

Fuel tank has dents on left side, inside tank looks good has minor rust, includes Kreem tank lining kit, tank not leak tested. Front rim has small ding [bend].

Everything in photos included, also Includes stock air box [not shown in photos] No exhaust

Side covers are broken, forks are rusted [spare set included from 72' lowers are different but uppers should work]
Steering stop is broken, hence the LH front fuel tank dent, spare lower triple clamp included with good steering stops. There is no brake fluid in reservoir, may have a leak. Front tire [19"] holds air but is NG.

Spare handlebars and rear fender included [fender on bike has crack].

One key included, ignition and fuel cap locks work.

New rear tire, Metzeler ME77 4:00-18 never used.




I really doubt that it was stored indoors since 2009. Cough.bull..cough...#$%*...

In any event I bought it along with an extra basket case engine knowing full well that this would be a complete tear down and rebuild.



Fast forward...This is the bike in the still assembled state for planning:





I bought an alum tank and seat pan. Decided since this  not to use the tank at first... need to do some rev work to it.

I like to newer style side covers so I need to fab some (laser cut) tabs and attach:




Another fast forward:

Here she is almost completely naked:



Doin' the side flip method:







I actually did this by myself! (And took pics) Yea.

And then the bad part.......



That is a mix of oil, water, PB blaster and marvel mystery oil...





I designed an engine stand bracket and had 2 sets laser cut...worked OK.



$50 Harbor Freight engine stand.



That's all for today...Happy easter..Find some eggs with treats in them...Nuts...bolts..etc..

[Stev-o]

Welcome and subscribed. You now know to never believe the PO!

Like that tank and seat, and great job on the engine stand. Need to make one as well.

So, do you think it has an 836 kit?

[70CB750]

Welcome!

[BLEAMA]

Did is the operator.

It's a shame that people do not care for these machines better. 


I destroyed the jugs  getting this apart. I soaked, heated, iced, to no avail. Pistons scrap too.  I was a little bit optimistic at the start but it went down hill quickly.


I ended up persuading it apart in a forceful way.



Head looked ok.



I have the cases, 2nd set of jugs (std), 2 heads, con rods, and crank at a local machine shop. They are cleaning, blasting and inspecting the components.  I could have blasted the outer surfaces, but was fearful of the residual grit. I would rather have a professional do it.  Should get these pieces back next week.

I will buy a new set of pistons based on measurements.

Bearings..TBD

Clutch, trans, and other internals looked OK.

[SOHC4 Cafe Racer Fan]

You have a busy April left.
Build time estimates are just that - estimates. Take your time and get things done right versus right now.

If you are not going with the Manx Lyta style tank, what is your new choice?

[BLEAMA]

I have stripped the original and will be adding a "Triumph esque" stainless rack on the top.

Color of the tank will be SAAB Edwardian Grey in memory of my 1988 900 SPG.

I will be using the Lyta at some point, but not this year. I love the way it looks.

[SOHC4 Cafe Racer Fan]

I will be using the Lyta at some point, but not this year. I love the way it looks.

Agreed.  The shape is bad-ass and classic.

[rtbmrgl]

[/quote]

HOLY SCHNIKES
 I see a lot of this on old Honda 90's cause of the head angle.

[BLEAMA]

There were a couple of fasteners missing on the top side of the case too, but as I mentioned, all other internals looked "visually" pretty good.  I still need to do some measuring.

[BLEAMA]

This is the tank that I swapped when I picked up the bike...  I had a great laugh!!

If you cant read the adhesive residue, it reads: "DON'T ASK TO RIDE MY BIKE AND I WONT ASK TO RIDE YOUR OLD LADY" 



Some very minor interior rust..outside ok..  It has since been stripped.

Master Cylinder

I endured this, as many of you have....

I looked at as many posts as I could...



What a PITA.  I was ready to throw this entire master away.  Works great now.


The rear rim was ok on this bike but once the rim and tire were separated, I opted for a couple on new DID from Z1.

Rebuilt hubs.  Polished the outside, painted the centers. Zinc spokes.

Front laced:



Rear laced:



I did not want to do the truing myself. Picked them up this weekend. K70's - 3.5 front and 4.0 rear.




If you are into Harleys or any brit bike and are near Hanover, Pa...This is the place to stop and chat. Café has a ton of parts and knowledge...he also holds some salt flat records. $84 to true my rims and install the tubes and tires.

[nccb]

84 for both rims is pretty damn good.  I went to my local honda store and they were trying to tell me it would be in the 200s

[BLEAMA]

That is what I found here.  The local Honda shop seemed confused when I asked if the could "true" a set of rims. Yamaha was willing, but a little too pricey.

I have been looking for some "go-to" shops for a variety of tasks..just in case.

There is an ebayer that sells parts.."parts bike heaven"  His shop is west of me, past Carlisle Pa.  He does work too, in addition to stripping bikes.

[BLEAMA]

Doing a "Government Job" at work..actually a couple..for my bike.

I am not using the "ears" and decided to make my own adaptor for the top of the bellows. 

I am partial to "A" or "D".  D will take less time on the milling machine, and will buff out nicely. A..will take a bit more time.




What is you favorite?

[SOHC4 Cafe Racer Fan]

Everyone has their opinion.  Mine is for "B"!

[SOHC4 Cafe Racer Fan]

I'd like to see you mill a dust cover for the shock lower, thread the top of the lower, and relieve the internal to accept a dust seal. Then, you'd get my vote... 

That would be a trick part!

[BLEAMA]

That would..Hmmmm.  I like the Bellow look.

Here is what the first looks like on a fork...3D printers rule...next to CB's.



Next one:



and the back...





I don't like the little lip on the top edge of the gaiter.  To accommodate it in the design would complicate the design (for me and my machining skills).

I was thinking about just 3d printing them and being done.  I have black material.

I saw some after I was conceiving this and was thinking somebody must have made these before..

[SOHC4 Cafe Racer Fan]

That would..Hmmmm.  I like the Bellow look.

Here is what the first looks like on a fork...3D printers rule...next to CB's.



Next one:



and the back...





I don't like the little lip on the top edge of the gaiter.  To accommodate it in the design would complicate the design (for me and my machining skills).

I was thinking about just 3d printing them and being done.  I have black material.

I saw some after I was conceiving this and was thinking somebody must have made these before..

3d printers DO rule!  That is cool.  I would just print them and black and use them.  That is awesome.  I still like B the best, but it's your bike!

[BLEAMA]

Do you have a pic of what yours look like?

[TyMatthews]

I was thinking about just 3d printing them and being done.  I have black material.

Do you think 3D-printed parts would be able to withstand the vibrational stresses and also survive UV exposure?

[BLEAMA]

FDM (Fused deposition modeling) uses ABS or other materials.  Some of the higher end machines/systems are designed to make parts that can be used as mini run production parts. So..the answer to your question is yes and also no depending on the type of 3d printer that one might use.  Printed solid, the material may hold a thread, but again this depends on the type of material that you are printing.

The pics that I attached are just ABS (styrene). They are ok for many applications. Probably would work for a gaiter holder.