Topic: My first complete build 72 CB750 - completed for now...

[SOHC4 Cafe Racer Fan]

Here are the specs on the AP calipers. I imagine one could make casting molds from an existing caliper.

[slikwilli420]

Here are the specs on the AP calipers. I imagine one could make casting molds from an existing caliper.

Likely what happened with the Kosman copies. Surprised they did a perfect copy, would have thought there would be legal issues with that. It would be hard to cast something that low volume and make money on it unless done overseas... far overseas. AP cost that for a reason, they are high quality. I would hope the Kosman ones will take all the spares from AP, but no way to be sure unless you buy one.

I agree with the OP, clearance issues will come into play just the same, and will with pretty much any 2-piston opposed caliper out there.

[754]

Best plan, open one up, measure the meat, figure the angle and mill some off.

A good plan though is wider trees, makes it easier.
 I did sneak a 6 piston onto a Ceriani GP.
 The wheel with the most clearance, Yamaha mags, we used a 18 inch front  likely has even  more clearance. 
 I checked a bunch of wheels.

[algophobe]

All something to think about. I did write to Kosman and he wasn't aware of any clearance issues, however he uses them mainly for Nortons and Triumphs. but if they are reproductions, same issues should apply as you guys indicate. For now I'll have to work on getting her reliably to GO, then worry about improving her STOPPAGE at a later time.

I did some work in tracing this ignition problem on cylinder 2/3. I first swapped the spark plug wires 1/4 for 2/3 and again nothing fires for 2/3. then i swapped the coils, and same issues. both coils get warm, but no sparks sent for 2/3 cylinders. I inspected the lines and they seem to be in good condition. of course i tested it by pressing the attached spark plug to the engine and pressing the started (looking for sparks). I would have to conclude that the timing signals aren't being sent from the contacts to the coil. Grossly, the PAMCO seems intact.

Correct me if i'm wrong but the PAMCO green wire is coming from the pick ups, which I changed in the second picture to blue for cylinder 1/4, and orange for 2/3. the red wire I changed to grey (black/white wire equivalent for the kill switch).


i'm now curious if this was the issue during the build as well, until it finally failed after 16 miles of riding. don't know if any of the experts here have encountered this. the question is now whether I should just get another PAMCO or switch to dynatek?

[scottly]

Spoke clearance isn't an issue with the Honda twin piston calipers, and the 32mm version has more clamping force than the AP.

[scottly]

Correct me if i'm wrong but the PAMCO green wire is coming from the pick ups, which I changed in the second picture to blue for cylinder 1/4, and orange for 2/3. the red wire I changed to grey (black/white wire equivalent for the kill switch).

Sorry, but I'm confused??!! To prove out the coils vs ignition, you only need to swap the two coil wires, which would be the blue and yellow wires with stock coils.

[algophobe]

Correct me if i'm wrong but the PAMCO green wire is coming from the pick ups, which I changed in the second picture to blue for cylinder 1/4, and orange for 2/3. the red wire I changed to grey (black/white wire equivalent for the kill switch).

Sorry, but I'm confused??!! To prove out the coils vs ignition, you only need to swap the two coil wires, which would be the blue and yellow wires with stock coils.

an experienced builder would do that of course. but you're dealing with a novice. actually i swapped the spark plug wires to see if there's anything wrong with the wires and work backwards. to swap the blue/yellow leads i have to remove the mounting bolts as they're in the way. since i built the wire harness from scratch i wanted to see if i some how fried it.

[algophobe]

Spoke clearance isn't an issue with the Honda twin piston calipers, and the 32mm version has more clamping force than the AP.

that set up is a twin piston on single disc? is there major difference with spoked wheels?

[scottly]

Yes, I'm using a 32mm twin piston caliper with a single 320mm Ducati disc, but this is not a bolt-on.
There are off-the-shelf parts that allow swapping the twin piston calipers. The only extra modification is to have the 550 275mm rotor(s) thinned from 7mm to 5mm.
You will need 750 F2/F3 forks; they will slide into your 550 triples.
You will need the twin piston caliper brackets that fit the F2/F3 fork lugs.
The caliper(s) will need to be shimmed to align with the disc(s) on the spoke wheel.
A single 275mm disc, with a 30mm twin piston caliper and the stock master is better than a  stock 550 38mm caliper, and even better with a 32mm twin piston caliper. Two 30mm calipers with dual discs would be better yet, but would be on the verge of needing a larger master. Two 32mm twin piston calipers with dual 275mm discs would be the ultimate stopping power with mostly bolt-on parts, but would require a larger MC. 

[SOHC4 Cafe Racer Fan]

I thought you could use the twin piston calipers with F2 forks.

[algophobe]

Christmas in 102 degrees So Cal. Hopefully will get a chance to spend time with the ol' girl putting this in this weekend.

i'm looking over the wiring. in comparison to PAMCO, which has a separate grounding wire on the ignition unit, the DynaS doesn't. i'm assuming it grounds via the bolt and plates?

I'm looking at this tutorial video below. the guy mentions something about nylon bushings to prevent grounding out of the coil at 13:45 minutes into the video. which i don't get. isn't that the point? the coils grounds thru the frame from the mounting bars?

[scottly]

The coils are not grounded to the frame; the yellow and blue primary wires are switched to ground by the points, or Pamco, or Dyna during the coil "charging"(dwell) time, and the ground is disconnected at the firing time for each coil, allowing the stored energy in the coil to discharge through the spark-plug gap.

[scottly]

I thought you could use the twin piston calipers with F2 forks.

With the F2/3 forks and the F2/3 Comstar wheel and 275mm, 5mm thick, 5 bolt rotors, the twin piston calipers and correct brackets are plug-and-play. With a spoke wheel and 6 bolt rotors, some "adjustments" are required.

[algophobe]

The coils are not grounded to the frame; the yellow and blue primary wires are switched to ground by the points, or Pamco, or Dyna during the coil "charging"(dwell) time, and the ground is disconnected at the firing time for each coil, allowing the stored energy in the coil to discharge through the spark-plug gap.

I see.. that's why if it's not discharging to the spark plugs, it heat up hotter than the coil that is working normally.
..then the Dyna IS grounded by the plate and screws to the engine case compared to Pamco.

[algophobe]

got the Dyna ignition on. everything seems to be "made better" for that extra 40 bucks. I like that you can attach the rotor magnet on, torque it down, then slip the plate over. a single wire (instead of 2 wires in PAMCO) routes under the engine and oil lines. the connection from timing plate simplified from 6 wires to only 3.

I change the spark plug wires back to the original PAMCO's that I bought. Yellow ones that was the inspiration for the color scheme initially. The system was strobe light timed to +10. the 2/3 coil fires more steadily than the PAMCO ever did.

i did noticed however the air screw had to be richened by 1/4 turn to run better. is that expected?

[algophobe]

finally got around to wrapping the pipes and coating them with high temp silicone seal. not sure how much performance improvements this would provide but, it was mainly done to hide the yellowish discoloration on the pipes from the heat.

now debating on whether or not to hang the end of the pipe. spoke to the cycle X guys, they say it could go either way. I was thinking of using the T bolt clamp and run a strap to cross bar of the frame and using another C clamp.

i've taken her for about 30 miles total with the new ignition system on and she runs like a champ. will be testing her up to Angeles Crest Highway hopefully soon.

[SOHC4 Cafe Racer Fan]

Looks great. I vote for a hanger to secure the pipe and reduce stress on the head.

[algophobe]

Looks great. I vote for a hanger to secure the pipe and reduce stress on the head.

thanks. man that mod to AP brakes have been marinating in my head, with the widened triple. kept being reminded when I head the squeak from those stock brakes. I see that Godfrey has some shims.

[Godffery]

Looks great. I vote for a hanger to secure the pipe and reduce stress on the head.

thanks. man that mod to AP brakes have been marinating in my head, with the widened triple. kept being reminded when I head the squeak from those stock brakes. I see that Godfrey has some shims.

I do indeed: https://godfferysgarage.com/project/anti-squeal-brake-shim/
Also; I recommend removing the Brake adjuster Bolt, Nut & Spring. Then place them carefully in a small mason jar, Bury the jar deep in the woods on a full moon, Draw a detailed map to it's location, Firmly secure said Map to anything that says Hardly Devidstone on it, Surround that with an army of handmade stick figures, Call at least 3 of your closest friends, Bribe with the promise of cold micro brewed beverages to come over immediately if not sooner, stand in a circle around your effigy of the dammed, sprinkle generously with cheep Convenience store whisky, Then set a blaze chanting... Never Again... Never Again!
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[SOHC4 Cafe Racer Fan]

Looks great. I vote for a hanger to secure the pipe and reduce stress on the head.

thanks. man that mod to AP brakes have been marinating in my head, with the widened triple. kept being reminded when I head the squeak from those stock brakes. I see that Godfrey has some shims.

I do indeed: https://godfferysgarage.com/project/anti-squeal-brake-shim/
Also; I recommend removing the Brake adjuster Bolt, Nut & Spring. Then place them carefully in a small mason jar, Bury the jar deep in the woods on a full moon, Draw a detailed map to it's location, Firmly secure said Map to anything that says Hardly Devidstone on it, Surround that with an army of handmade stick figures, Call at least 3 of your closest friends, Bribe with the promise of cold micro brewed beverages to come over immediately if not sooner, stand in a circle around your effigy of the dammed, sprinkle generously with cheep Convenience store whisky, Then set a blaze chanting... Never Again... Never Again!
No automatic alt text available.

 

[algophobe]

Looks great. I vote for a hanger to secure the pipe and reduce stress on the head.

thanks. man that mod to AP brakes have been marinating in my head, with the widened triple. kept being reminded when I head the squeak from those stock brakes. I see that Godfrey has some shims.

I do indeed: https://godfferysgarage.com/project/anti-squeal-brake-shim/
Also; I recommend removing the Brake adjuster Bolt, Nut & Spring. Then place them carefully in a small mason jar, Bury the jar deep in the woods on a full moon, Draw a detailed map to it's location, Firmly secure said Map to anything that says Hardly Devidstone on it, Surround that with an army of handmade stick figures, Call at least 3 of your closest friends, Bribe with the promise of cold micro brewed beverages to come over immediately if not sooner, stand in a circle around your effigy of the dammed, sprinkle generously with cheep Convenience store whisky, Then set a blaze chanting... Never Again... Never Again!
No automatic alt text available.

Those adjuster screw is completely useless? Ugh! I was devastated when i tightened it to much and broke one of the raised edge on the screws.  Bought two extra just in case. By the way Godfrey, this seems to be no way of purchasing those said shims from your website.

[Godffery]

Looks great. I vote for a hanger to secure the pipe and reduce stress on the head.

thanks. man that mod to AP brakes have been marinating in my head, with the widened triple. kept being reminded when I head the squeak from those stock brakes. I see that Godfrey has some shims.

I do indeed: https://godfferysgarage.com/project/anti-squeal-brake-shim/
Also; I recommend removing the Brake adjuster Bolt, Nut & Spring. Then place them carefully in a small mason jar, Bury the jar deep in the woods on a full moon, Draw a detailed map to it's location, Firmly secure said Map to anything that says Hardly Devidstone on it, Surround that with an army of handmade stick figures, Call at least 3 of your closest friends, Bribe with the promise of cold micro brewed beverages to come over immediately if not sooner, stand in a circle around your effigy of the dammed, sprinkle generously with cheep Convenience store whisky, Then set a blaze chanting... Never Again... Never Again!
No automatic alt text available.

Those adjuster screw is completely useless? Ugh! I was devastated when i tightened it to much and broke one of the raised edge on the screws.  Bought two extra just in case. By the way Godfrey, this seems to be no way of purchasing those said shims from your website.

Correct; completely useless! The only possible issue would be if your brake line was torqued in a way that would cause the caliper to push in or out from center over the rotor.  It should sit comfortably free floating.

 My web site is not yet fully interactive for direct online purchases, So to order parts, use the (Contact Godffery's Garage) option on the main page. Or you can contact me direct.   (jstephens7@wi.rr.com)

[tshrey]

I just found this build for the first time.  Very nice.  Did you ever consider adding a spacer under the back of the tank?  It looks like if you did you would have a perfect line from the tank to the tail.

[algophobe]

I just found this build for the first time.  Very nice.  Did you ever consider adding a spacer under the back of the tank?  It looks like if you did you would have a perfect line from the tank to the tail.

problem is there is no clearance between the rear mounting bracket that I made and the cowl. unless I use a bigger cushion on the cowl but that would ruin the lines as well.
some angles makes it very obvious like this angle. but most shots you can't tell. I was hesitant about posting this particular photo for that very reason, but then said f' it.

thinking about it again, i guess i could bump up the whole rear cowl up to make those adjustments. hmmm.

[algophobe]

some minor progress and set backs. I fabbed a little strap to hold down the rear exhaust.

then notice the knob on the speedo was bent somehow, so I went to bend it back and bam! it snapped off. I guess it gave me an opportunity to redo the speedo and tach in exact matching 2.5 inch gauges, but it may require some drill and retap. these things are really cheap. they're Dime City Originals, but I looked on Cognito and 4into1, appears to be the same gauges, but twice the price.

https://www.dimecitycycles.com/2-5-inch-chrome-mini-speedometer-with-black-face-and-led-indicator-lights.html

https://4into1.com/drag-specialties-mini-speedometer-with-indicator-lights-black-face-2240-60/