Topic: 1972 CB750 Resto-mod build

[jerry h]

Nice write up, and of course really nice looking SOHC!   (I wish my garage was as spotless as yours too )

[Davez134]

Nice write up, and of course really nice looking SOHC!   (I wish my garage was as spotless as yours too )

Thanks Jerry! It's easy to have a clean garage in Vegas though, most everything is less than 10-15 years old! (plus I'm a clean freak) I checked out your build... Very nice! I really wanted to go the restoration route but mine had too much gone already. I really like yours!

[Davez134]

I thought I was done with this project but the longer I have this bike, the more I learn. I was riding the bike really easy since the the rebuild, especially since the temperature out here was well over 100 most of the summer.  When I started riding it a little harder, I noticed that it did not want to rev much past 6500 and would hesitate badly.  I decided to take a short break from riding in the crazy heat here and figure it out.  With the help of all of you on this forum, I found my spark advancer shaft was out of true and very "chewed up" looking where the advancer rides. (one more thing the previous owners hacked up) I got a new shaft from a member here and trued to .002" after installing with a dial gauge. I also soda blasted my carbs (they looked so dirty compared to rest of bike now) and cleaned out all the tiny passages using a copper wire. Now the bike pulls strong all the way. I think I've finally got it!  Here's a few new pics.  Some guys at work started their CB750 projects as well. The red one in last pic belongs to a friend from work...

carbs finally clean as the rest of the bike


Ride out to Pioneer Saloon in Goodsprings, NV. Built 1913

[Davez134]

I finally got rid of my MAC and picked up this Motogp Werks 4-1. The MAC wasn't terrible but scraped on right handlers a couple of times and was only meant to be temporary. This one has spring loaded flanges for easy removal and quality seems great! Will post pics when I get it installed, as I'm just waiting on new crush gaskets.

[calj737]

Have the same exhaust for my bikes. You're right, the build quality is excellent. On your bike, I think the kicked up muffler end will help with the lines on your bike, and improve clearance over the prior unit.

Handsome ride you've got there.

[Davez134]

Got exhaust installed on the bike today. Wow this thing sounds good! 

[Retro Rocket]

Looks good...

[Davez134]

Looks good...

Thanks! I remember you saying watch the scraping on right handers (and I did a few times) with previous exhaust. I took it through the turns at Red Rock today and had great clearance. Seat of the pants feel much better than MAC too!

[Retro Rocket]

Looks good...

Thanks! I remember you saying watch the scraping on right handers (and I did a few times) with previous exhaust. I took it through the turns at Red Rock today and had great clearance. Seat of the pants feel much better than MAC too!

 

[SOHC4 Cafe Racer Fan]

Dave,

Just a heads up that this bike has been nominated for BOTM April 2015.  Please respond that you "accept" the nomination in the BOTM thread.  http://forums.sohc4.net/index.php?topic=145568.0

Your rear wheel looks like it might be a 16 or 17. 

Don

[Davez134]

Dave,

Just a heads up that this bike has been nominated for BOTM April 2015.  Please respond that you "accept" the nomination in the BOTM thread.  http://forums.sohc4.net/index.php?topic=145568.0

Your rear wheel looks like it might be a 16 or 17. 

Don

I responded in BOTM thread. First, thanks everyone for the nominations. Unfortunately this bike was recently sold to fund my current project, so I'm pretty sure it's not eligible.

Don, rear wheel on this one was a 16. That's what came on there when I bought it, had no idea until after powder coating them that 18 was factory size. I really learned a lot from building this one. First bike project ever. New one is coming along quickly though!

[el pachuco]

Got exhaust installed on the bike today. Wow this thing sounds good! 

Beautiful bike! Love the header!!
Where did you get the exhaust system?

[SOHC4 Cafe Racer Fan]

That's a MotoGP Werks pipe.

[budman]

That's a MotoGP Werks pipe.

Are they self-supporting at the head or do they have a bracket under the frame?

[SOHC4 Cafe Racer Fan]

That's a MotoGP Werks pipe.

Are they self-supporting at the head or do they have a bracket under the frame?

You should fabricate a bracket to the frame.  See the bracket attached to the foot peg mount in the photo?

[budman]

That's a MotoGP Werks pipe.

Are they self-supporting at the head or do they have a bracket under the frame?

You should fabricate a bracket to the frame.  See the bracket attached to the foot peg mount in the photo?

I zoomed in on all the photos and don't see a bracket attached to the front or rear foot peg mounts.

[Davez134]

I'll try to find a picture of it for you. I just made a bracket out of flat stock aluminum, bent to a slight "s" shape, rounded the edges and drilled holes.  I sold the bike but I may have a pic on my camera.

[Davez134]

That's a MotoGP Werks pipe.

Are they self-supporting at the head or do they have a bracket under the frame?

You should fabricate a bracket to the frame.  See the bracket attached to the foot peg mount in the photo?

I zoomed in on all the photos and don't see a bracket attached to the front or rear foot peg mounts.

No pics on my camera, but here's from an old post. You can kinda see it in the top pic mounted to pipe, and in the other pic on the bottom where it mounts to passenger peg mount.

http://forums.sohc4.net/index.php/topic,138009.msg1577641.html#msg1577641

[budman]

No pics on my camera, but here's from an old post. You can kinda see it in the top pic mounted to pipe, and in the other pic on the bottom where it mounts to passenger peg mount.

http://forums.sohc4.net/index.php/topic,138009.msg1577641.html#msg1577641

Thanks for posting.  I see it now.  Unfortunately the rear peg mounts were badly damaged on my frame when I got it, so off they came.  I won't be able to use a setup like that.

[SOHC4 Cafe Racer Fan]

That's a MotoGP Werks pipe.

Are they self-supporting at the head or do they have a bracket under the frame?

You should fabricate a bracket to the frame.  See the bracket attached to the foot peg mount in the photo?

I zoomed in on all the photos and don't see a bracket attached to the front or rear foot peg mounts.

Look closer at the near end of the pipe (near the exhaust exit), and you will see an aluminum bracket extending upward toward the passenger footpeg.

[SOHC4 Cafe Racer Fan]

No pics on my camera, but here's from an old post. You can kinda see it in the top pic mounted to pipe, and in the other pic on the bottom where it mounts to passenger peg mount.

http://forums.sohc4.net/index.php/topic,138009.msg1577641.html#msg1577641

Thanks for posting.  I see it now.  Unfortunately the rear peg mounts were badly damaged on my frame when I got it, so off they came.  I won't be able to use a setup like that.

Ah, looks like you found it.  Do you have any of the passenger footpeg left?  If not you could likely still weld a bracket to that area of the frame.  I've seen people mount brackets all the way to the top frame rail shock mount but that looks fugly.  You definitely SHOULD use a bracket, so there's not all of that vibration and stress on the exhaust ports of the head.

[Davez134]

You could make a bracket that mounts to where your rear sets attach too. Or, some sort of clamp on the frame tube, low near where the passenger peg triangles used to be. It doesn't have to be super strong, just take some tension off exhaust flanges.

[budman]

You could make a bracket that mounts to where your rear sets attach too. Or, some sort of clamp on the frame tube, low near where the passenger peg triangles used to be. It doesn't have to be super strong, just take some tension off exhaust flanges.

I was thinking about the possibility of both of those scenarios.  The only exhaust that I've found that claims to be self supporting in the Yamiya.  I like the shorter muffler/baffle tube of the Yamiya, but the whole thing is a little funky looking and is only available in chrome or black.  I would prefer a stainless steel exhaust.

[Davez134]

You could make a bracket that mounts to where your rear sets attach too. Or, some sort of clamp on the frame tube, low near where the passenger peg triangles used to be. It doesn't have to be super strong, just take some tension off exhaust flanges.

I was thinking about the possibility of both of those scenarios.  The only exhaust that I've found that claims to be self supporting in the Yamiya.  I like the shorter muffler/baffle tube of the Yamiya, but the whole thing is a little funky looking and is only available in chrome or black.  I would prefer a stainless steel exhaust.

Yes, it claims to be self supporting. It may be fine without a rear support. But, hold am exhaust system with your hand by just the part where it connects to the flanges. Then move itaround a bit. You'll see how over time it can cause wear. This has been debated before, but personally I will always find a way for a rear support.

[eM3rge]

I got lucky this bike is in my garage now