Topic: '78 750K first project by a car guy...

[RandyBMC]

So some photos of the progress.  I've been working at it a lot, but just haven't sat down to upload all of the photos.

Here is the frame - bare metal, frame off restoration!





















Got my new tires too.  I've since mounted them as well.



Did the All Ballz bearings and installed the triple tree.



I used the proper tool and it worked out pretty easy (you can see it laying on the floor).



I pulled the engine off of the stand and mounted it in the frame using the "lay it on its side" approach.  Much easier than pulling it!









Then I started work on hanging the suspension.  It goes so much easier building with nice clean parts compared to pulling junk out of baskets or getting rusted parts off!







I rebuilt the left and right controls, which looked atrocious, and now they feel like new!  I don't have many photos of that, since I used the forums here to do the assembly/rebuild.  I'll have to take a couple of the finished products.  You can see the left control in this photo,  along with my current work - ELECTRICAL!





Here is the battery box - I am waiting for the new ATC/ATO fuse box from Hondaman, but I have a couple of bits from Rick's on there now.  I'm making a top bracket for the R/R to fit the stock voltage regulator mount.





Now a request for some advice.  I bought the coils from one of the CB750 specialists, but the mounts had the hole oriented sideways.  I have made it work, but the coil orientation is different.  Does anyone see any issues with this?





Last night, I mounted the rear turn signals, the gauges, the rear shocks, and hung the rear wheel.  Photos to follow.

[madmtnmotors]

I pulled the engine off of the stand and mounted it in the frame using the "lay it on its side" approach.  Much easier than pulling it!

LOL!

Nice job on the C-hook, but your lifting lug at the top is oriented 90 degrees off. If you rotate the loop at the top 90 degrees (or add another loop between the lifting lug and chain hook) then the hoist comes in from the side of the bike instead of the front, like this:










Of course, when the bike is striped to the frame, then the lay-down method works fine. I have had to pull several engines that did not require the full "frame off" treatment, so the lay-down method is not always practical. It only took me ten minutes, working alone, to wiggle the engine into the frame in the pictures above, and it only took that long because I had to stop to take pictures. 

[RandyBMC]

Hey Wilbur,

Yeah, I just used the hoist to pull it off the engine stand, so the orientation didn't matter.  I turned it around when I used it to pull the engine out - which I think I have pictures of in this thread somewhere (it actually is oriented correctly as long as I flip it around).

The "lay it on its side" worked great to keep everything scratch free!  If I need to pull it for something once the bike is together again, I will certainly use the hook again.  It's a great shortcut!

[madmtnmotors]

Ahhhh... that sounds better! 

[RandyBMC]

Got some new bits from Dime City.  My turn signals, gauges, fuel line and filter, and my Bates style tail light.

I started with the rear turn signals, using Adel clamps, which have rubber isolation for vibration damping, which I thought would be a slick way to mount them. Initially, I went with this set up:







Then I mounted up the rear wheel (which in itself is pretty exciting), and realized that I wouldn't be able to get the same clearance as the rear suspension compressed as I should.  Easily fixed by swapping the clamps around so the flat part was out instead of in:





You can see the gauges in that photo too, but I didn't like the mounting solution - they looked too far apart to me.  So I used the DCC bracket, which meant I had to relocate my choke cable.  I mounted it in the original gauge mount hole, and I think it turned out pretty clean.  I am going to get a stainless hex stud to put in the old hole to make it look a little more finished.



I am now thinking of mounting the front turn signals with the headlight bucket.  This is the factory bucket, but I also have a slightly larger "British style" bucket that I would like to use.  It has non-metric threads though, so I need to drill and tap that bucket if I want to go this route with the turn signals.



A couple more shots with the rear wheel on.





I then disassembled the horn and refinished it.  The chrome was unsalable, so I wire wheeled it, sanded it down and hit it with POR15 Top Coat.  It came out nicely.  I had to install new wiring as well, as the PO had snipped them right at the base of the horn.  It looks nice all mounted up.





I then reinstalled my refurbished center stand.  Originally I was only going to use the side stand I snapped up and refinished, but until I get it sorted, I think I'm keeping the center stand.







I installed the rear shocks too!



Now it is on with the wiring process, and finish up the front end.  Having never done motorcycle carbs, I am debating whether or not to tackle the PD42s myself or send them out for a pro...  I have rebuilt Webers for old Porsches in the past, but these are smaller and I'm older!  Advice from those who have been there and done it?

[cbxr750]

Very clean and simple build. Looks great! keep it up!

[therobbstory]

Stellar thread! I've got the same bike. Wondering if you plan on holding onto that stock seat. If not, I'd like to take it off your hands. Shoot me a PM if you're interested in selling.

[SOHC4 Cafe Racer Fan]

You may want to ditch those black shock guards.  It will require some disassembly, but they look much cleaner without them.

[RandyBMC]

I don't know man, I kinda like them.  It makes the chrome springs a little more subtle.  I completely dissassembled the stock shocks to see if they could be saved (they couldn't due to rust on the shafts).  Maybe down the road I'll pull these apart too and see if I like the cover-less look.

[Stev-o]

Looking great Randy, excellent update.  Best way to clean carbs is will an ultrasonic cleaner. 

[RandyBMC]

Work continues...

I chopped the rear fender liner so I can use it, then mounted it by drilling a hole on each side of the metal bracket on the triangle frame rail and used button head stainless steel allens to retain it.  It works well and looks pretty clean I think.







Horn mounted and wired, but that clutch cable is just not going to work.  I am ordering a shorter one from 4 into 1.



Grips, controls and brake mounted.



Front wheel, fender, brake mounted up, chain hung, rear brake stay and rod mounted and adjusted. Wiring continues...





I tapped the front bucket so I can do the wiring.  I also got HondaMan's start saver relay and fuse block.  BEAUTIFUL!  Mounting the battery box with the new equipment and the oil tank next.  It is a lot of fun seeing it all come together!!

[RandyBMC]

Battery box is in and all wired.  I had to lower the rear of the box a bit by just trimming the metal sleeve in the rubber mount by a couple of millimeters to keep the seat from touching it.  Easy.

I also rebuilt the passenger foot pegs and mounted those.

Then I did a little mocking up.  Still more wiring to go for the headlight bucket and the rear signals/brake light.

[Stev-o]

Nothing like nice , clean wiring, great job Randy. I need to convert my K4's fuseblock.

What is the plan for paint?

[RandyBMC]

Thanks!

I'm leaning toward a Toyota light grey from an FJ Cruiser then the stripe on the tank in either a bright blue or a black.  Then pinstripe the super sport style stripe in gold or silver.  This is the color for the tank and side covers:



Not my truck, just a Google search for the color.  I'm still not positive on which way I'm going to go.

[Stev-o]

Its very hard picking a color....guess that's why I have 3 blue bikes in the garage!

[RandyBMC]

I'm trying to finish up the wiring now.  I have seen the fix to make the Dime City speedo turn signal indicator work with a two into one diode.  I can't find one.  I do see diodes, and I will admit my ignorance in not knowing which ones I would need to make a two into one (soldering together at one end).

Here's a page of diodes - any suggestions?

https://www.radioshack.com/apps/search-results#stq=diode&stp=1&facets%5Bshopify%5D%5B%5D=product_type

Thanks!

[Desert-SOHC]

You can use 2 separate diodes without issue. There just a one way "valve" for electricity that only let current go one direction.

[RandyBMC]

I have two wire turn signal units too.  I'm just wondering about the amp and voltage I need for the diode - refer to the link at Radio Shack I posted above.

I got my APE pods and have been working on the vent lines so I can mount the oil tank.  I have a '78 manufactured after December '77, so my air separator has an inlet on the side for the valve cover, an outlet on the top to the air box (which I don't have), and an outlet with the clear "L" to the drain line on the bottom.  Can I just leave the top line of the separator open to vent to atmosphere?  I worry about there not being suction created by the air box.  Would it be better just to vent the valve cover to a "draft line" drain at the side of the bike?

I also have a '78 style oil tank, which only has a vent for the tank at the bottom that goes to the crankcase vent barb, so that's pretty straightforward.

Where does the fuel tank vent go?  I've looked through the manual and can't see it (and I didn't have one when I got the bike).  Just down and out between the swingarm and frame (by the overflow tubes for the carb)?

Thanks for the help!!!

[Desert-SOHC]

You will need at least 3 watt diodes to be safe. I'm an overkill kinda guy and would use 6 watt diodes, there kinda the standard in auto wiring.

My separator has been eliminated and the valve cover and tank vent to a generic aftermarket M/C chrome vent filter. But then it wasn't hooked up when I got it either, it was missing A LOT of parts when I got it and it barely ran...but it had its 4 into 4 pipes! I can tell you that it had a molded vent tube that hooked around the swingarm on the brake side that vented to open air. That was all that was left of my system.

And that's not a tank vent, its a spill tube and I'm not sure where it exactly goes. Just make sure it has an easy path to the ground and away from really hot things incase it gets used.

[martin99]

I'm trying to finish up the wiring now.  I have seen the fix to make the Dime City speedo turn signal indicator work with a two into one diode.  I can't find one.  I do see diodes, and I will admit my ignorance in not knowing which ones I would need to make a two into one (soldering together at one end).

Here's a page of diodes - any suggestions?

https://www.radioshack.com/apps/search-results#stq=diode&stp=1&facets%5Bshopify%5D%5B%5D=product_type

Thanks!

I've just done this on my SRX. I used two 3 amp 50v diodes. Actually, the voltage doesn't really matter, as long as it's enough to cope with a 12v system there's no upper limit really.

Easy to do, but if I lived in the US I would have made my life even easier by just springing for this - for the price, just not worth messing about-

https://www.superbrightleds.com/moreinfo/motorcycle-accessories/metric-bike-diode-kit/1190/2805/

[RandyBMC]

Thanks man - that's perfect!

[RandyBMC]

I got the Yuasa sealed battery yesterday, and after some yard work for my wife, I plan on finishing up wiring today.

I have a question on the starter solenoid.  From the pics above and the one I'm posting on this, do I have it right?  I wired it based on what o could figure out from the manual. 

Battery hot and wire harness plug to the forward terminal on the solenoid. (Green/red solenoid wire)
Starter cable to the rear side of the terminal.  (Yellow/red solenoid wire)



Thanks!

[RandyBMC]

It is hard to see from the photo, but they are backwards.  The harness to the plug for the fuse and the battery hot are on the rear and the starter is on the front post of the solenoid.  See the factory diagram below:

[SKTP]

looks great...I need to update my electronic and fuses

[SOHC4 Cafe Racer Fan]

If you update to a blade style fuse block, get one with a couple of extra channels, so you can carry some spare fuses.