Author Topic: Pin2Hot's 73 CB750  (Read 56624 times)

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Offline calj737

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Re: Pin2Hot's 73 CB750
« Reply #225 on: April 30, 2018, 02:39:57 PM »
The guy who upholstered my Cafe seat, added a split seam in the center of it, above the tail light. Making those curves gets VERY tricky even for the pros.
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"Of all tyrannies, a tyranny sincerely exercised for the good of it's victim may be the most oppressive. It may be better to live under robber barons than under omnipotent moral busybodies. The robber baron's cruelty may sometimes sleep, his cupidity may at some point be satiated, but those who torment us for our own good will torment us without end for they do so with the approval of their own conscience." - C.S. Lewis

Offline algophobe

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Re: Pin2Hot's 73 CB750
« Reply #226 on: May 08, 2018, 08:04:08 AM »
Beautiful work with the seat so far. I like how you are not afraid to tackle on different materials and elements of the build yourself. Growing up my mom was a seamstress, and she would bring home Stacks and stacks of material to sew and I would pack them up throw it in the van and turn it back in to the manufacturer. During Summers I used to help her sew to earn some spending money. And it's strange how satisfying that all the skills with working with different materials over a life time can converge in a bike build.
Ducati Hypermotard 950 SP 2020 "Percolo"
Honda cb750 café 1972 "Satmui"
Kawasaki zx6r 2005 "Garuda"
Kawasaki zx7r 1998 "Dharma" (stolen)
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Offline Pin2Hot

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Re: Pin2Hot's 73 CB750
« Reply #227 on: May 08, 2018, 08:41:05 AM »
Beautiful work with the seat so far. I like how you are not afraid to tackle on different materials and elements of the build yourself. Growing up my mom was a seamstress, and she would bring home Stacks and stacks of material to sew and I would pack them up throw it in the van and turn it back in to the manufacturer. During Summers I used to help her sew to earn some spending money. And it's strange how satisfying that all the skills with working with different materials over a life time can converge in a bike build.

That's great!  My grandmother sewed all of her own clothes and my mother taught me how to use our sewing machine when I was a kid.  I always found it very satisfying.  I made this big stuffed camel in 7th grade for home economics and I remember how I couldn't wait to get to the class to finish it up.  I also attempted a pair of jeans recently that kind of sort of worked out . . . I actually wanted to work some of the denim into the bike somewhere but I decided against it.  My grandmother passed on her sewing machine to me so it's serving a new life making things instead of collecting dust in a closet.

There's something tangible about sewing that power tools and welders don't provide.  Maybe it's the up close, directly-in-your-hands requirement of sewing that makes it satisfying.  I couldn't agree more how skills can converge, great way to put it.  Thanks for the kind words.

Offline Pin2Hot

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Re: Pin2Hot's 73 CB750
« Reply #228 on: May 20, 2018, 11:32:19 AM »
I'm getting close to sending things off for paint / powder coat so I'm spending a lot of time fixing tiny holes and filling in some of my poorer welds.  I found that brazing in some silicon bronze has been filling things in nicely even though it means a bit more elbow grease is required to get things smooth.  I've chosen to fill holes with metal as I'm going to powder coat the frame and swingarm.  I asked some local powder coat shops and they said I could use JB Weld to fill things in but I ran risk of it popping and blowing out the work.  So, now I get to spend a ton of time filing down more shtty welds in an effort to hide the previous shttier welds.  Hey, whatever it takes I guess.

Testing out my plan:


Looking a lot better after filing:


Added some more bronze, now it's time to file and I'll finish up with emery cloth to smooth it all out.  Makes me really wish I had a pipe sander / polisher.


I also sewed the toughest part of the seat, really happy with out how turned out!


Top stitch:

Offline DurangoCB

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Re: Pin2Hot's 73 CB750
« Reply #229 on: May 21, 2018, 11:26:35 AM »
If there were a Like button, I would hit it.  Since I don't have much to say and so many threads in the Project subforum are met with crickets. 

Looks awesome and learning new skills is so great. 
1971 CB500 Four- current project http://forums.sohc4.net/index.php/topic,170622.0.html
1978 CX500- next in line

Offline Pin2Hot

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Re: Pin2Hot's 73 CB750
« Reply #230 on: May 29, 2018, 06:43:00 AM »
Oh hey!  I spent the holiday weekend filling in welds and shaping things with a file.  My arms are dead but as I type this, the frame, swing arm and other parts are in the car waiting to be chauffeured out to the powder coater.   The frame will be a cement gray (think Toyota Tacoma / Scion TC), the swing arm and other bits will be black.  By the end of the week (or whenever the guy gets finished) I should have some pretty sexy looking things back in the garage.  Then it's time to clean EVERYTHING, re-assemble and wire this thing up.  I've said it before but I've been really looking forward to wiring this bike for a while.  I've got some interesting ideas that I think should look pretty slick.

Brazed and shaped:


Closeup:


Oh yeah, I also made a license plate bracket:


Items to be coated: frame, swing arm, steering stem / triple tree, engine mounts, brake stay, battery box:


I'll report back as soon as things are colorful.


Offline Pin2Hot

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Re: Pin2Hot's 73 CB750
« Reply #231 on: June 18, 2018, 07:48:53 AM »
Annnnd we're back.

Powder coat looks incredible and the color is exactly what I was looking for.  I've definitely learned a few lessons in terms of making sure things are absolutely perfect before getting something coated but I'm completely happy with the results.

Petting my new puppy.


Swing arm and frame w/ battery box.


Frame closeup:


Swingarm closeup:


License plate bracket with new LED plate light:


Temporary assembly to see how it looks and determine final tail light placement.  Turns out, where I wanted to place the taillight (hanging it off the tail) made it look like the rider had a tail light nutsack sooooo I'm moving it to above the license plate mount just above the plate light:


My brother demonstrating the riding position.  I like the somewhat aggressive stance, not too rear set.  Although it does make me want to make an extra set of rear set mounts to play around with foot peg position.  But I'll keep what I've got for now:


I've started to mount the mUnit and other electrical gadgetry so the final assembly phase begins now.  However, my time in the garage over the next few months is going to be very limited, hopefully I'll find time to finish this up before things get cold again . . .

Offline andy750

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Re: Pin2Hot's 73 CB750
« Reply #232 on: June 19, 2018, 03:12:04 AM »
Subscribed! Love the detailed photos and the one of the riding position nails it. Great work thanks for sharing.
Current bikes
1. CB750K4: Long distance bike, 17 countries and counting...2001 - Trans-USA-Mexico, 2003 - European Tour, 2004 - SOHC Easy Rider Trip , 2008 - Adirondack Tour 2-up , 2013 - Tail of the Dragon Tour , 2017: 836 kit install and bottom end rebuild. And rebirth: http://forums.sohc4.net/index.php/topic,173213.msg2029836.html#msg2029836
2. CB750/810cc K2  - road racer with JMR worked head 71 hp
3. Yamaha Tenere T700 2022

Where did you go on your bike today? - http://forums.sohc4.net/index.php?topic=45183.2350

Offline DurangoCB

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Re: Pin2Hot's 73 CB750
« Reply #233 on: June 19, 2018, 04:27:08 PM »
Looking really good.  I am really liking any frame color that isn't black right now.  And I'm sure my tastes will swing back to not liking anything non-black at some point LOL  The tail lights/brackets are a nice, simple solution.  Works with that subframe nicely! 

I'm shooting for August 1st completion date.  I'll race ya!
1971 CB500 Four- current project http://forums.sohc4.net/index.php/topic,170622.0.html
1978 CX500- next in line

Offline Pin2Hot

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Re: Pin2Hot's 73 CB750
« Reply #234 on: July 05, 2018, 06:30:37 AM »
I've been working on the seat and mounting things as quickly as possible while I have time.  Here's some progress.

My seat consists of two parts: the seat pan, which is two pieces of bendy plywood laminated together and the cushion which is another piece of stiff plywood with gel and closed cell foam.  The cushion will be covered with some suede and stitched up all purty.  The seat pan will also get a walnut veneer once I've created all the mounting holes and what not.

Laminating the seat pan (you can never have too many clamps):


One thing thing I realized after I popped the pan out, the metal pan below buckled quite a bit during the powdercoat process and those buckles transferred to the wooden pan.  It's not a huge deal but I'd definitely do this differently next time:


Underside of the pan, showing the threaded inserts I'll be using to attach the pan to the metal of the frame below:


Mounting holes:


Cushion.  It won't sit this high as some of the fabric will be tucked under to make sure it's nice and taught around the stiff plywood base.  Still trying to solve exactly how this will be attached to the pan but I have a few ideas.


More or less the final position of the cushion:


Underside of the cushion for those who are curious.  I wanted to hide the small area where the original battery box mounted so the cushion has a small extension on it.  That's why there's a section that's "enclosed".


Pretty happy with the look, I think it'll really pop once the walnut veneer is laminated.  Stay tuned!

Offline Pin2Hot

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Re: Pin2Hot's 73 CB750
« Reply #235 on: July 11, 2018, 06:25:54 PM »
I got the cushion all finished up and I'm pretty happy with the results.  I need to do a bit of tucking to get it looking all nice and neat.  I'll do that once I get the veneer laminated on.  For the most part, that's the entire seat.  Kinda nice to finally see and feel it's true shape.  It's about as comfortable as a supermoto or a dirt bike.  Overall I'm pretty happy with it.

Cushion:


Pretty good length, covers up some holes:


Underside for the curious.  This is prior to me stapling things down.  There are 3 stainless steel button head screws I glued into the cushion board.  I have some nylon nuts under the seat pan that will grab them and secure it to the pan:


I also decided to place my taillight in this position instead of hanging off the bottom of the seat.  I think it looks much better down here:


Hope to have the engine back in this weekend and the seat 100% finished up.

Offline DurangoCB

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Re: Pin2Hot's 73 CB750
« Reply #236 on: July 13, 2018, 06:54:18 AM »
Crap, I forgot we were racing.  I better take the day off work and get busy.  :)
1971 CB500 Four- current project http://forums.sohc4.net/index.php/topic,170622.0.html
1978 CX500- next in line

Offline Pin2Hot

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Re: Pin2Hot's 73 CB750
« Reply #237 on: October 08, 2018, 12:44:34 PM »
Hey.  I'm not dead.  Had my first kid so the bike has taken a backseat for the foreseeable future.  However, in the 2 seconds a day I get to myself, I've been working on the harness.  I'm using 16 ga stranded for most everything and covering each conductor in paracord to make it all purty.  Here are a few examples:

Power/ground to the PCB:


An unfinished to/from mUnit connector:




Here's an updated drawing of what I'm using to keep track of things:


Kids are fun . . . already thinking of what his first bike is going to be.  CRF50F?

Offline Ilja

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Re: Pin2Hot's 73 CB750
« Reply #238 on: November 28, 2018, 07:53:49 AM »
First, please enjoy the wonderful sunset we witnessed in mid-MO/IL this wonderful Memorial Day weekend.  We spent all weekend (and the previous weekend) building that dock cover.  It was a LOT of work and my back and legs are killing me today but it was worth it:



Second, enjoy the beeeeeautiful stainless steel exhaust that arrived from our friends up North, Ripple Rock.  The copper collar things are only temporary as I got studs that were WAY too long. 


The mid-pipe is going to get modified to shorten it up and angle it up/out.  That'll let me attach a hanger point on the muffler to support the rear of the exhaust from the rearset mount.


I'm going to miss my deadline of getting this done in time to go to Tulsa, OK next weekend but work will continue.  I hate having to keep moving my deadline but that's the way it goes sometime.  I'll keep at it.

Congrats on your kid! Hopefully you have a balanced work/private life so you can enjoy both the family and the bikes.  :D

Awesome project, so many big modifications.... I especially like that you just made a PCB for electrical connections and also that fuel tank is really nice.

Can I ask what outside diameter those stainless header pipes have? Looks good... is it 38mm ?  :)

Offline Pin2Hot

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Re: Pin2Hot's 73 CB750
« Reply #239 on: December 14, 2018, 06:21:26 AM »
Congrats on your kid! Hopefully you have a balanced work/private life so you can enjoy both the family and the bikes.  :D

Awesome project, so many big modifications.... I especially like that you just made a PCB for electrical connections and also that fuel tank is really nice.

Can I ask what outside diameter those stainless header pipes have? Looks good... is it 38mm ?  :)

Thanks Ilja.  The baby has certainly put things on hold but this project WILL be completed, just don't know when.

The pipes are 38mm.


I realize this is a digital set of calipers but the battery is dead.  :)

Offline Pin2Hot

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Re: Pin2Hot's 73 CB750
« Reply #240 on: July 01, 2019, 12:37:31 PM »
Geez, it's been a while.  This project has languished for years so a little 7 month dormant period ain't nothin!  I recently moved (for hopefully the last time) and have gotten everything back out and begun re-assembly.  Priorities now are wiring things up which I plan to document heavily, maybe even shoot some videos and create a little series about wiring it up from scratch.

Assembly:


I have to thread a rod to create a custom lower engine hanger as the stock hanger is bent and I'm no longer using the stock footpegs which makes the stock one far too long.  You can see the unthreaded rod at the base of the rear-set mount:


Making sure I find center to mount the m-Unit:



Question - BOLT, HEX. (8X40) 93101-08040-0B - Can anyone confirm that this is indeed an M8 - 1.25 pitch bolt?  I'm having trouble threading these into the upper triple tree and I'd like to run a tap through them to clean up the threads as it's possible some powder coat got stuck in there.  Just need to confirm I'm not crazy before destroying the threads in this part . . .

Maybe it'll get done this summer? 

Offline calj737

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Re: Pin2Hot's 73 CB750
« Reply #241 on: July 01, 2019, 03:40:49 PM »
8x40 is 1.25 pitch, BUT, some triple trees also used M7. They’re very close so yours may be that.
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"Of all tyrannies, a tyranny sincerely exercised for the good of it's victim may be the most oppressive. It may be better to live under robber barons than under omnipotent moral busybodies. The robber baron's cruelty may sometimes sleep, his cupidity may at some point be satiated, but those who torment us for our own good will torment us without end for they do so with the approval of their own conscience." - C.S. Lewis

Offline Pin2Hot

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Re: Pin2Hot's 73 CB750
« Reply #242 on: July 03, 2019, 08:44:39 AM »
8x40 is 1.25 pitch, BUT, some triple trees also used M7. They’re very close so yours may be that.

So M7 x 1.25 pitch?

Offline calj737

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Re: Pin2Hot's 73 CB750
« Reply #243 on: July 03, 2019, 02:38:13 PM »
M7x1.0 is standard if that's the issue with your triple.
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"Of all tyrannies, a tyranny sincerely exercised for the good of it's victim may be the most oppressive. It may be better to live under robber barons than under omnipotent moral busybodies. The robber baron's cruelty may sometimes sleep, his cupidity may at some point be satiated, but those who torment us for our own good will torment us without end for they do so with the approval of their own conscience." - C.S. Lewis

Offline RAFster122s

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Re: Pin2Hot's 73 CB750
« Reply #244 on: July 03, 2019, 06:18:51 PM »
Naturally the M8 isn't going to thread into the M7 hole if that is the case on your triple tree...obviously. And they are so close in size it could be easy to confuse them. The bolts on my triple tree are chromed it appears, so that might be a clue on you sorting out the difference in your bolt collection from disassembly.  The M7 will stand out in a pile of M8 bolts...but if mixed in a M6 and M8 pile it might not unless the bolts are chromed like mine.

Good luck sorting it out.

David
David- back in the desert SW!

Offline Pin2Hot

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Re: Pin2Hot's 73 CB750
« Reply #245 on: July 12, 2019, 12:21:25 PM »
It was an M8x40 - 1.25 pitch bolt.  Turns out quite a bit of powder coat got caught up in the threads for the lower fork clamp bolts.  I got myself a M8 1.25 tap and chased the threads.  Now the front end is coming back together.  Thanks for the input everyone.

Getting back together:


Also mocking up the bracket for the PCB, will be utilizing the old speedo/tach mounting plate holes:


Gonna be a tight fit:



Offline Godffery

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Re: Pin2Hot's 73 CB750
« Reply #246 on: July 22, 2019, 08:29:21 AM »
"Gonna be a tight fit"
 I would say too tight for sure.  It may work fine for a while, but eventually the rubbing of the wires on the neck will likely start causing electrical gremlins.
I've worked in R&D for a large Moto company and these kind of fitments in long term usage caused many unnecessary issues and were the Bane of our existence.   (Focusing too closely on form, can cost in critical function)
 Just a heads up.

 Dig'n the overall build, Lot's going on there!

Offline Pin2Hot

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Re: Pin2Hot's 73 CB750
« Reply #247 on: July 22, 2019, 01:48:29 PM »
It may work fine for a while, but eventually the rubbing of the wires on the neck will likely start causing electrical gremlins.

In my professional life, loose wires and overall wear n tear on interconnects have wasted countless hours of my time.  I'm definitely reconsidering the spacing.  It actually makes me wish I'd used two boards instead of one to split things down the middle.  Oh well, add it to the list of "things I won't do in the future".  In any case, thank you for the advice, things will be shifting around to minimize / eliminate unnecessary strain on those wires.

Speaking of wires, I'm finally wiring in earnest.  I have a handful of smaller gauge wires that need to be bumped up to fit into various connectors as well as extending them to reach.  Most of the wires from the Powerarc ignition need to be lengthened to reach the front of the bike so I'm soldering / shrinking the butt joints. (disregard the chipped powder coat, that's what I get for powder coating before getting the valve seats cut)



Little Deutsch snake connecting the coils to the encoder wheel:


There are several places that will require single wire connections that I'm struggling to find "sexy" bullet connectors.  There are some made for RC hobbyists which look nice but I'm afraid of their longevity.  I also need double bullet connectors to connect a single wire to two.  Anyone use anything like that?

Offline calj737

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Re: Pin2Hot's 73 CB750
« Reply #248 on: July 22, 2019, 02:48:08 PM »
Gang your singles into a multi. Easier that way.
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Offline Godffery

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Re: Pin2Hot's 73 CB750
« Reply #249 on: July 23, 2019, 02:09:45 AM »
To deal with that chipped powder coat, you could dress the fin edges with a file and it will also give it some nice detailed contrast with the black.