Author Topic: Pin2Hot's 73 CB750 (Read 56893 times)

Pin2Hot · « **Reply #125 on:** May 23, 2017, 06:52:42 AM »

Thanks for the kind words, guys. It's been a lot of fun. There's a whole lot more comin.

Quote from: Godffery on May 22, 2017, 06:00:03 PM

I recommend using POR15 for the internal sealing. it is much easier to work with & I have had great results with it.
http://www.por15.com/Fuel-System-Restoration_c_17.html

I think this is THE eternal debate here on SOHC4: whether POR15 or Caswell is better. I've had a lot of experience with two part epoxies which is why I'm comfortable using Caswell (plus, I already bought it). One of these days someone needs to do a deep, scientific dive into which is better. Sadly, I'm only going to perpetuate the argument here...

I messed around last night trying to sort out my rearset mounts. I had a plan going in thinking I was just going to cut out some plate and weld up a simple mount on the back edge of the frame...well as always it's never that simple.

Since I won't be using the stock pegs, I should have enough room on the engine mount bolt to put a plate on either side of the frame to which I'll mount the rearsets. I'm also not going to use the drum brake pivot tube and lever adjuster so those are getting hacked off. I'll probably have to figure out / adjust the pivot point of my rear sets (from a 2000 929) so that the drum brake can still be actuated but, like most problems in life, it can be solved with bending.

Rearset location with crappy mounting plate "drawn" in:

Side note: as a kid, the cool boot guard on Honda sportbikes always stood out to me so now I'm putting them on MY bike.

754 · « **Reply #126 on:** May 23, 2017, 07:13:16 AM »

Keep in mind 77/78 f rear motor and Peg stud are longer. That would allow you to mount a 3/8 or so aluminum plate firmly to frame, the mount your stuff to that..
May have to shorten the longer suds on one side.

calj737 · « **Reply #127 on:** May 23, 2017, 08:10:24 AM »

Another sexy option is to abandon the rear drum and replace it with a rear disk. You can do that in 2 ways, the SuperSport models had stock disc, Or, CognitoMoto makes a disc adapter to fit your stock hub retaining your Cush drive. That gets you to a rear master cylinder, loses the pivot tube, and easy to adapt your more modern rear sets.

Pin2Hot · « **Reply #128 on:** May 23, 2017, 10:57:30 AM »

Quote from: calj737 on May 23, 2017, 08:10:24 AM

Another sexy option is to abandon the rear drum and replace it with a rear disk. You can do that in 2 ways, the SuperSport models had stock disc, Or, CognitoMoto makes a disc adapter to fit your stock hub retaining your Cush drive. That gets you to a rear master cylinder, loses the pivot tube, and easy to adapt your more modern rear sets.

If I hadn't already powder coated the rims and re-laced the original hub I might consider it. I'll go full disc brakes on the NEXT bike. I didn't realize Cognito has so many conversion options. Pretty slick selection.

calj737 · « **Reply #129 on:** May 23, 2017, 12:24:36 PM »

You don't have to change rims. The spokes are the same. Unlacing yours to replace with his is pretty simple (if you opt to). And he can send it powder coated directly to you.

Pin2Hot · « **Reply #130 on:** May 26, 2017, 07:10:54 AM »

Quote from: calj737 on May 23, 2017, 12:24:36 PM

You don't have to change rims. The spokes are the same. Unlacing yours to replace with his is pretty simple (if you opt to). And he can send it powder coated directly to you.

I'll save it for the next project, already too far down the rabbit hole on this one already.

Not much work this week but started the process of making a bracket for the rearsets.

Cardstock template:

Cut out and mocking up mounting holes:

I'm going to the ole metal store this weekend to pick up some 3/16 steel as well as some aluminum sheet to start making the battery box. I've got some neat plans for that one.

And this little guy showed up last night (the pipe, not Bob laying in the background):

That's the Cone Engineering Big Mouth 13 that'll mate up to my Hindle SS exhaust that should be showing up any day now.

Pin2Hot · « **Reply #131 on:** May 29, 2017, 07:11:05 PM »

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.

greenjeans · « **Reply #132 on:** May 30, 2017, 06:51:42 AM »

nice looking exhaust. Really digging those Cone big mouths

Pin2Hot · « **Reply #133 on:** May 30, 2017, 07:47:31 AM »

Quote from: greenjeans on May 30, 2017, 06:51:42 AM

nice looking exhaust. Really digging those Cone big mouths

Thanks! I'm super happy with the fit and can't believe how light it is. I'll chop up the mid-pipe tonight and try to get a final fit-up this week. I plan on using the right rearset mount as a support point for the muffler. Once I get it angled the way I want it should work out pretty well. This'll be my first attempt at welding stainless so I'm going to practice on the part I cut out and try to set up some kind of backing gas configuration so I don't sugar the inside of the weld.

calj737 · « **Reply #134 on:** May 30, 2017, 07:56:43 AM »

Do you know whether its 304 or 321 stainless? And it would serve you well to run a purge while welding it back together.

Pin2Hot · « **Reply #135 on:** May 30, 2017, 12:22:34 PM »

Quote from: calj737 on May 30, 2017, 07:56:43 AM

Do you know whether its 304 or 321 stainless? And it would serve you well to run a purge while welding it back together.

Not entirely sure. I reached out to Kemp to see what grade SS it is so we'll see. Isn't there a catch-all filler material that can be used for 304/321? Something like 308 or 309 filler rod? I'm not sure I'll even need any filler material as the sections I'm cutting out of the mid-pipe should just butt up against one another so I can wash the joint closed. Regarding purge, I'll have to get creative with that because I don't want to have to buy an additional regulator just for this one weld.

calj737 · « **Reply #136 on:** May 30, 2017, 02:22:42 PM »

If your fit-up is good enough, then you can just fuse it. Don't know if you have much stainless experience, but, it MOVES when hot. 4-6 tacks around the circumference at a minimum. The diameter of that pipe, I'd probably aim towards 10-12 myself. Figure the wall thickness is ~0.058, so 60 amps is plenty. Full pedal mash it, tack, kill the pedal. Keep your torch over it for 10 seconds for postflow to prevent infiltration of impurities. Your tack should come out close to gold in color if you've had sufficient gas coverage.

For 321, I'd use 321 wire, or at least 316. If you hit the welds promptly with a clean stainless brush, you'll remove the color almost completely.

So for a down-dirty purge, plug the header end with aluminum foil balls. Tape up the tailpipe end with numerous criss-cross pieces of Blue Tape. Make your tacks. Then poke a hole in the tape and just run gas from your torch into the pipe for about 3-5 minutes, header above your welding. It will be more than adequate for what you're doing.

Pin2Hot · « **Reply #137 on:** May 31, 2017, 06:22:26 AM »

Cal, great advice. I was able to cut the pipe down last night and get the exact fit-up and placement I was looking for. I'll use those techniques to tack and weld it up when I get a chance later this week. It was pretty scary cutting that tubing but I was able to get it nice and square.

Before:

After (with custom electrical tape weld):

New angle dangle:

And great position to support the rear end from the right rearset:

It didn't occur to me until I saw the profile of the bike that it reminded me of my old GSXR's pipe:

It's really taking shape, getting pretty pumped. After I get the rearsets and exhaust hanger mounted, I'll begin to focus on the oil lines and carbs so that I can finally fire it up.

calj737 · « **Reply #138 on:** May 31, 2017, 06:38:29 AM »

I like to use a spring to support the tailpipe, personally. It allows the pipe to move ever so slightly without a rigid attachment. You could install a stainless threaded bung on the backside, then a button head screw into it, loop the spring over it, and then attach the other end to the rearset bracket. Makes detachment super quick.

BTW, use the largest cup you own to weld stainless with. And, about 3-5 seconds of pre-flow over the area to be welded helps purge the atmosphere. Unlike carbon or aluminum, stainless you hit with full amps from the onset. Else, you sit there and "bake" it. You'll get dark grey welds which are weaker and prone to cracking. Whack it and go! Travel speed is very fast too with stainless because it wets so quickly. I love welding it, but it sure tries your patience trying to keep it square

SOHC4 Cafe Racer Fan · « **Reply #139 on:** May 31, 2017, 08:40:58 AM »

At least you have a few attachment points (looking at the rearset) for some exhaust support.

Pin2Hot · « **Reply #140 on:** June 10, 2017, 03:02:51 PM »

I've been on vacation for the past week and haven't done a single thing on the bike but I thought I'd share what I did on the tail end of my time off. I spent it working on 75 foot metal sailboat in Tulsa OK. It's called SV Seeker and Doug, the owner, has quite a following on YouTube. Check him out here. I emailed him in February asking him if I could be a part of his build crew and he accepted.

I've been working since Friday doing just one of the many tasks still remaining on this ship. When it's done, it'll be transported via custom transport structures that Doug is making (think moving a house) and it'll be moved to the furthest inland port in the US: the Port of Catoosa. From there, it's 18 locks and 1000 miles away from the Gulf. It's going to be a research vessel chartered by universities or anyone with an adventure in mind. Doug and his girlfriend Betsy are incredibly wonderful people and it's truly been a great time working down here. I still have this evening and a bit of work tomorrow but thought I'd share just a few photos of what I've seen down here so far.

I've been welding in some nuts that will hold down equipment to the deck which I thought was super clever. I'll get some pics of my work later, right now we're avoiding the mid day heat but we'll get back out there this evening and finish up.

SV Seeker:

My work. The holes in the deck hide some large threaded nuts that will let equipment be attached to the deck for whatever may require it.

Doug overseeing the arrival of his new set of wheels for the transporter.

It's been fun. He's always looking for more help so check out his website and sign up to be a part of this massive project.

SOHC4 Cafe Racer Fan · « **Reply #141 on:** June 12, 2017, 08:42:00 AM »

WOW!!!

Pin2Hot · « **Reply #142 on:** June 16, 2017, 11:53:21 AM »

I'm having major issues finding ANYone in my area to bend up a hoop for my monoshock swingarm. Anyone out there willing to help me out or point me in the right direction?

The people I've asked usually answer in one or all of the following ways:
- job is too small / we're too busy
- bend radius is too tight / I don't have the proper die
- I don't want to be responsible if it fails

I really don't want to buy a tubing bender just to do this one job and it's the ONLY thing holding me up from finishing. Let me know if there are any good ideas out there, thanks!

SOHC4 Cafe Racer Fan · « **Reply #143 on:** June 16, 2017, 12:03:01 PM »

Quote from: Pin2Hot on June 16, 2017, 11:53:21 AM

I'm having major issues finding ANYone in my area to bend up a hoop for my monoshock swingarm. Anyone out there willing to help me out or point me in the right direction?

The people I've asked usually answer in one or all of the following ways:
- job is too small / we're too busy
- bend radius is too tight / I don't have the proper die
- I don't want to be responsible if it fails

I really don't want to buy a tubing bender just to do this one job and it's the ONLY thing holding me up from finishing. Let me know if there are any good ideas out there, thanks!

I am not surprised as to these responses. You may want to simply give them specs for the tube and bend and waive any responsibility/warranty of fitness for particular purpose. In other words, will you bend me a tube according to these specs and I will waive any claims as to its fitness for your purpose. You will have no one to blame but you if it fails, but you might have a better chance getting your tube, especially from the person making the third type of response.

calj737 · « **Reply #144 on:** June 16, 2017, 02:02:56 PM »

What specs on the hoop are you after?

Pin2Hot · « **Reply #145 on:** June 16, 2017, 02:31:20 PM »

I have an "ideal" version in mind but the radius required for it is what's causing a lot of consternation with the guys I'm hitting up. All dimensions shown are in centimeters. Tubing diameter is 1".

Ideal hoop - center radius of ~9cm (~3.5")

Realistic hoop - center radius of 5"

calj737 · « **Reply #146 on:** June 16, 2017, 03:29:40 PM »

1" steel tube, what wall thickness?

Pin2Hot · « **Reply #147 on:** June 16, 2017, 08:13:47 PM »

1" chromoly, 0.095.

calj737 · « **Reply #148 on:** June 16, 2017, 08:50:16 PM »

Pretty thick, and pretty tough stuff to bend on a 3" radius. 0.062 DOM would be plenty strong and much more manageable.

Pin2Hot · « **Reply #149 on:** June 17, 2017, 09:20:29 AM »

Picked up some 1" 0.065 DOM today along with some other stuff to make my rearset brackets. I found a guy who's willing to at least look at the project next week so hopefully it works out. Fingers crossed.

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Author Topic: Pin2Hot's 73 CB750 (Read 56893 times)