Author Topic: Finally rebuilding my CB 750  (Read 13985 times)

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Offline Leino

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Re: Finally rebuilding my CB 750
« Reply #100 on: October 28, 2023, 02:19:30 AM »
Got some Racetech gold valves I'm gonna drop in the forks to get rid of some of the annoying features of FZR forks in stock form. They come with four or five sets of little springs nowadays so plenty of options for me to mess things up  ;D

Offline newday777

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Re: Finally rebuilding my CB 750
« Reply #101 on: October 28, 2023, 03:33:42 AM »
Got some Racetech gold valves I'm gonna drop in the forks to get rid of some of the annoying features of FZR forks in stock form. They come with four or five sets of little springs nowadays so plenty of options for me to mess things up  ;D
Nice. I need to get some for my stock forks to bring them to life.
Did you get the motor back together? Is it still 65mm as you said early on in this build?
I might take my K5 up to where Mike is moving to today to check it out as winter is threatening to show it's ugly face next week and it'll most likely be our last 79°F of the year around here in New England.
Stu
Honda Parts manager in the mid 1970s Nashua Honda
My current rides
1975 K5 Planet Blue my summer ride, it was a friend's bike I worked with at the Honda shop in 76, lots of fun to be on it again
1976 K6 Anteres Red rebuilding project, was originally my brother's that I set up from the crate, it'll breath again soon!
Project 750s, 2 K4, 2 K6, 1 K8
2008 GL1800 my daily ride and cross country runner

Prior bikes....
1972 Suzuki GT380 I had charge of it for a year in 1973 while my friend was deployed and learned to love street riding....
New CB450 K7 after my friend returned...
New CB750 K5 Planet Blue, demise by ex cousin in law at 9,000 miles...
New CB750 K6 Anteres Red, to replace the totaled K5, I sold this K6 at 45k in 1983, I had heavily modified it, many great memories on it and have missed it greatly.....
1983 GL1100A, 1999 GL1500 SE, 1999 GL1500A

Offline Leino

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Re: Finally rebuilding my CB 750
« Reply #102 on: October 28, 2023, 01:47:38 PM »
Still 65mm and still haven't finished it. I have... can't remember how many bikes of my own and working on other peoples stuff like the five-yamaha-mix engine and some useless crap I couldn't care less about but need to finish plus a dayjob  ::)

Offline Leino

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Re: Finally rebuilding my CB 750
« Reply #103 on: October 29, 2023, 12:04:52 AM »
Didn't mean to sound rude but feels like I'm still cleaning out the shop from other peoples bikes and engines and I stopped working on any of that stuff years ago  ;D

Yamaha engine was my own idea and I'm happy to go through with it. Last version was worth 40+hp over stock, hoping to get 50+ with this one.

Offline newday777

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Re: Finally rebuilding my CB 750
« Reply #104 on: October 29, 2023, 01:13:31 AM »
I didn't take it as rude, just that you have a packed plate.
40+ and 50+ hp increases are a good amount of increase.
I'd love to have the $$$ to put into a CB750 motor to get that increase of hp, but alas, I  have to be careful with expenditures.......
Stu
Honda Parts manager in the mid 1970s Nashua Honda
My current rides
1975 K5 Planet Blue my summer ride, it was a friend's bike I worked with at the Honda shop in 76, lots of fun to be on it again
1976 K6 Anteres Red rebuilding project, was originally my brother's that I set up from the crate, it'll breath again soon!
Project 750s, 2 K4, 2 K6, 1 K8
2008 GL1800 my daily ride and cross country runner

Prior bikes....
1972 Suzuki GT380 I had charge of it for a year in 1973 while my friend was deployed and learned to love street riding....
New CB450 K7 after my friend returned...
New CB750 K5 Planet Blue, demise by ex cousin in law at 9,000 miles...
New CB750 K6 Anteres Red, to replace the totaled K5, I sold this K6 at 45k in 1983, I had heavily modified it, many great memories on it and have missed it greatly.....
1983 GL1100A, 1999 GL1500 SE, 1999 GL1500A

Offline Leino

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Re: Finally rebuilding my CB 750
« Reply #105 on: October 29, 2023, 01:59:08 AM »
I didn't take it as rude, just that you have a packed plate.
40+ and 50+ hp increases are a good amount of increase.
I'd love to have the $$$ to put into a CB750 motor to get that increase of hp, but alas, I  have to be careful with expenditures.......
21% increase in displacement and almost 50% increase in RWHP using stock parts from five different engines  ;D
A fun project and the only issue with the first one was rods, can't rev it as high as we would want to but that's about to change... from 11600 to 12800rpm with the latest modifications, can rev it even more if it likes it, we will have to wait and see.
125 at the wheel was with 11200 limiter and power was still going up rapidly.

Offline Leino

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Re: Finally rebuilding my CB 750
« Reply #106 on: October 29, 2023, 09:50:08 AM »
Correction, the old version used parts from three different Yamahas and Suzuki cylinder sleeves, new version uses parts from five different Yamaha engines.
Not that this has anything to do with my CB  ;D

Offline Leino

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Re: Finally rebuilding my CB 750
« Reply #107 on: May 08, 2024, 09:54:09 AM »
Seat done.


Offline MRieck

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Re: Finally rebuilding my CB 750
« Reply #108 on: May 08, 2024, 04:36:12 PM »
Nice work kiddo. ;) I have 1 more CB engine in me.....it can be almost 115RWHP to the rear with stroker built F2.....probably more..... I have most of the parts.
Owner of the "Million Dollar CB"

Offline newday777

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Re: Finally rebuilding my CB 750
« Reply #109 on: May 08, 2024, 05:33:08 PM »
Nice work kiddo. ;) I have 1 more CB engine in me.....it can be almost 115RWHP to the rear with stroker built F2.....probably more..... I have most of the parts.
I need one Mike!
Stu
Honda Parts manager in the mid 1970s Nashua Honda
My current rides
1975 K5 Planet Blue my summer ride, it was a friend's bike I worked with at the Honda shop in 76, lots of fun to be on it again
1976 K6 Anteres Red rebuilding project, was originally my brother's that I set up from the crate, it'll breath again soon!
Project 750s, 2 K4, 2 K6, 1 K8
2008 GL1800 my daily ride and cross country runner

Prior bikes....
1972 Suzuki GT380 I had charge of it for a year in 1973 while my friend was deployed and learned to love street riding....
New CB450 K7 after my friend returned...
New CB750 K5 Planet Blue, demise by ex cousin in law at 9,000 miles...
New CB750 K6 Anteres Red, to replace the totaled K5, I sold this K6 at 45k in 1983, I had heavily modified it, many great memories on it and have missed it greatly.....
1983 GL1100A, 1999 GL1500 SE, 1999 GL1500A

Offline PeWe

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Re: Finally rebuilding my CB 750
« Reply #110 on: May 08, 2024, 10:04:17 PM »
Nice work kiddo. ;) I have 1 more CB engine in me.....it can be almost 115RWHP to the rear with stroker built F2.....probably more..... I have most of the parts.
I need one Mike!
A build thread with all details with  photos would be fantastic! ;D
Displacement, head details, cam, carbs etc, etc... ;)
Compression with a cheap tester on top of that ;D
CB750 K6-76  970cc (Earlier 1005cc JMR Billet block on the shelf waiting for a comeback)
CB750 K2-75 Parts assembled to a stock K2

Updates of the CB750 K6 -1976
http://forums.sohc4.net/index.php/topic,180468.msg2092136.html#msg2092136
The billet block build thread
http://forums.sohc4.net/index.php/topic,49438.msg1863571.html#msg1863571
CB750 K2 -1975  build thread
http://forums.sohc4.net/index.php/topic,168243.msg1948381.html#msg1948381
K2 engine build thread. For a complete CB750 -75
http://forums.sohc4.net/index.php/topic,180088.msg2088008.html#msg2088008
Carb jetting, a long story Mikuni TMR32
http://forums.sohc4.net/index.php/topic,179479.msg2104967.html#msg2104967

Offline MRieck

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Re: Finally rebuilding my CB 750
« Reply #111 on: May 09, 2024, 03:57:16 AM »
Nice work kiddo. ;) I have 1 more CB engine in me.....it can be almost 115RWHP to the rear with stroker built F2.....probably more..... I have most of the parts.
I need one Mike!
A build thread with all details with  photos would be fantastic! ;D
Displacement, head details, cam, carbs etc, etc... ;)
Compression with a cheap tester on top of that ;D
F2 head with large ports, TMR-36, 70mm stroker pistons with raised wrist pins, Carrillo's, undercut transmission etc. Those are the parts I have so far. ;) I was buying a fresh Marine 6mm stroker crank from George S but he can't find it. ;D ;D
Owner of the "Million Dollar CB"

Offline MRieck

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Re: Finally rebuilding my CB 750
« Reply #112 on: May 09, 2024, 04:04:05 AM »
Nice work kiddo. ;) I have 1 more CB engine in me.....it can be almost 115RWHP to the rear with stroker built F2.....probably more..... I have most of the parts.
I need one Mike!
A build thread with all details with  photos would be fantastic! ;D
Displacement, head details, cam, carbs etc, etc... ;)
Compression with a cheap tester on top of that ;D
F2 head with large ports, TMR-36, 70mm stroker pistons with raised wrist pins, Carrillo's, undercut transmission etc. Those are the parts I have so far. ;) I was buying a fresh Marine 6mm stroker crank from George S but he can't find it. ;D ;D
Billet block too....how did I forget that one. ::) ;D
Owner of the "Million Dollar CB"

Offline newday777

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Re: Finally rebuilding my CB 750
« Reply #113 on: May 09, 2024, 04:05:46 AM »
Nice work kiddo. ;) I have 1 more CB engine in me.....it can be almost 115RWHP to the rear with stroker built F2.....probably more..... I have most of the parts.
I need one Mike!
A build thread with all details with  photos would be fantastic! ;D
Displacement, head details, cam, carbs etc, etc... ;)
Compression with a cheap tester on top of that ;D
F2 head with large ports, TMR-36, 70mm stroker pistons with raised wrist pins, Carrillo's, undercut transmission etc. Those are the parts I have so far. ;) I was buying a fresh Marine 6mm stroker crank from George S but he can't find it. ;D ;D
Billet block too....how did I forget that one. ::) ;D

👍😎
Stu
Honda Parts manager in the mid 1970s Nashua Honda
My current rides
1975 K5 Planet Blue my summer ride, it was a friend's bike I worked with at the Honda shop in 76, lots of fun to be on it again
1976 K6 Anteres Red rebuilding project, was originally my brother's that I set up from the crate, it'll breath again soon!
Project 750s, 2 K4, 2 K6, 1 K8
2008 GL1800 my daily ride and cross country runner

Prior bikes....
1972 Suzuki GT380 I had charge of it for a year in 1973 while my friend was deployed and learned to love street riding....
New CB450 K7 after my friend returned...
New CB750 K5 Planet Blue, demise by ex cousin in law at 9,000 miles...
New CB750 K6 Anteres Red, to replace the totaled K5, I sold this K6 at 45k in 1983, I had heavily modified it, many great memories on it and have missed it greatly.....
1983 GL1100A, 1999 GL1500 SE, 1999 GL1500A

Offline PeWe

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Re: Finally rebuilding my CB 750
« Reply #114 on: May 09, 2024, 10:16:53 AM »
Nice work kiddo. ;) I have 1 more CB engine in me.....it can be almost 115RWHP to the rear with stroker built F2.....probably more..... I have most of the parts.
I need one Mike!
A build thread with all details with  photos would be fantastic! ;D
Displacement, head details, cam, carbs etc, etc... ;)
Compression with a cheap tester on top of that ;D
F2 head with large ports, TMR-36, 70mm stroker pistons with raised wrist pins, Carrillo's, undercut transmission etc. Those are the parts I have so far. ;) I was buying a fresh Marine 6mm stroker crank from George S but he can't find it. ;D ;D
Billet block too....how did I forget that one. ::) ;D


Cam?
The nice streetable cam with even power from low too high numbered 125-70 or for a CB750 more extreme one? ;D

My Billet block is parked for the moment. My K6 runs so well so I cannot change it. 125-75 cam idles really well.

I got the pistons for the Billet block gas ported (horisontal), and I'm eager to find out what that will bring except more rlng wear ;D

I have another slow engine build that I have planned 890cc for. Upper case milled for Billet block just for sure.

Billet block make the engine to look very special. It blends together really well with the later heads as K6 and 392 with the same style. I guess F2 will look fantastic too.
« Last Edit: May 09, 2024, 10:54:14 AM by PeWe »
CB750 K6-76  970cc (Earlier 1005cc JMR Billet block on the shelf waiting for a comeback)
CB750 K2-75 Parts assembled to a stock K2

Updates of the CB750 K6 -1976
http://forums.sohc4.net/index.php/topic,180468.msg2092136.html#msg2092136
The billet block build thread
http://forums.sohc4.net/index.php/topic,49438.msg1863571.html#msg1863571
CB750 K2 -1975  build thread
http://forums.sohc4.net/index.php/topic,168243.msg1948381.html#msg1948381
K2 engine build thread. For a complete CB750 -75
http://forums.sohc4.net/index.php/topic,180088.msg2088008.html#msg2088008
Carb jetting, a long story Mikuni TMR32
http://forums.sohc4.net/index.php/topic,179479.msg2104967.html#msg2104967

Offline MRieck

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Re: Finally rebuilding my CB 750
« Reply #115 on: May 09, 2024, 02:44:40 PM »
Nice work kiddo. ;) I have 1 more CB engine in me.....it can be almost 115RWHP to the rear with stroker built F2.....probably more..... I have most of the parts.
I need one Mike!
A build thread with all details with  photos would be fantastic! ;D
Displacement, head details, cam, carbs etc, etc... ;)
Compression with a cheap tester on top of that ;D
F2 head with large ports, TMR-36, 70mm stroker pistons with raised wrist pins, Carrillo's, undercut transmission etc. Those are the parts I have so far. ;) I was buying a fresh Marine 6mm stroker crank from George S but he can't find it. ;D ;D
Billet block too....how did I forget that one. ::) ;D


Cam?
The nice streetable cam with even power from low too high numbered 125-70 or for a CB750 more extreme one? ;D

My Billet block is parked for the moment. My K6 runs so well so I cannot change it. 125-75 cam idles really well.

I got the pistons for the Billet block gas ported (horisontal), and I'm eager to find out what that will bring except more rlng wear ;D

I have another slow engine build that I have planned 890cc for. Upper case milled for Billet block just for sure.

Billet block make the engine to look very special. It blends together really well with the later heads as K6 and 392 with the same style. I guess F2 will look fantastic too.
Yes Per 125-70....it is the best all around cam I've found in regard to idle quality, smooth power and good A/F across the board when on the dyno. Lateral (horizontal) gas ports are good.....I wouldn't worry about excessive top ring wear. If anything it really stabilizes right ring in the groove and greatly reduces flutter at high RPM. It really helps XA rings.
 That block does look nice on the engine Per.....I was very specific about extended finning for cooling and the aesthetic appeal. Laverda did it with their engines and I always thought it looked awesome.
 I have a set of F2 cases too. In general everything associated with the F2 is stronger.
Owner of the "Million Dollar CB"

Offline bear

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Re: Finally rebuilding my CB 750
« Reply #116 on: May 09, 2024, 08:43:26 PM »
What are you thinking regards valve's and guides Mike?
The older I get the faster I was.

Offline MRieck

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Re: Finally rebuilding my CB 750
« Reply #117 on: May 10, 2024, 07:00:06 AM »
What are you thinking regards valve's and guides Mike?
Iron guides from Yamiya. I move the C clip .080" up the guide so it sits a bit lower in the head for retainer/seal clearance. F2 valves that are out of Europe....stem tips are tougher. I don't know....maybe run lash caps and not have to worry about stem tip wear anyway. I have several sets of Beehive springs too.
 The Yamiya iron guides are really nice pieces.
Owner of the "Million Dollar CB"

Offline PeWe

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Re: Finally rebuilding my CB 750
« Reply #118 on: May 10, 2024, 08:39:07 AM »
CycleX SS 34mm valves for K if not too tall for an F2 head?
(F2 valve stem a little bit shorter.)
4 pcs $48US
« Last Edit: May 10, 2024, 12:09:15 PM by PeWe »
CB750 K6-76  970cc (Earlier 1005cc JMR Billet block on the shelf waiting for a comeback)
CB750 K2-75 Parts assembled to a stock K2

Updates of the CB750 K6 -1976
http://forums.sohc4.net/index.php/topic,180468.msg2092136.html#msg2092136
The billet block build thread
http://forums.sohc4.net/index.php/topic,49438.msg1863571.html#msg1863571
CB750 K2 -1975  build thread
http://forums.sohc4.net/index.php/topic,168243.msg1948381.html#msg1948381
K2 engine build thread. For a complete CB750 -75
http://forums.sohc4.net/index.php/topic,180088.msg2088008.html#msg2088008
Carb jetting, a long story Mikuni TMR32
http://forums.sohc4.net/index.php/topic,179479.msg2104967.html#msg2104967

Offline MRieck

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Re: Finally rebuilding my CB 750
« Reply #119 on: May 10, 2024, 04:40:44 PM »
CycleX SS 34mm valves for K if not too tall for an F2 head?
(F2 valve stem a little bit shorter.)
4 pcs $48US
I wouldn't give CycleX 1 cent of my money.
Owner of the "Million Dollar CB"

Offline Leino

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Re: Finally rebuilding my CB 750
« Reply #120 on: May 10, 2024, 11:17:44 PM »
Nice work kiddo. ;) I have 1 more CB engine in me.....it can be almost 115RWHP to the rear with stroker built F2.....probably more..... I have most of the parts.
Thanks Mike! Still have a lot to do but it's finally coming along the way I wanted it in the first place.

Offline bear

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Re: Finally rebuilding my CB 750
« Reply #121 on: May 13, 2024, 12:13:38 AM »
CycleX SS 34mm valves for K if not too tall for an F2 head?
(F2 valve stem a little bit shorter.)
4 pcs $48US
I wouldn't give CycleX 1 cent of my money.

 ;)

The older I get the faster I was.

Offline Leino

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Re: Finally rebuilding my CB 750
« Reply #122 on: May 22, 2024, 09:42:46 PM »
CycleX SS 34mm valves for K if not too tall for an F2 head?
(F2 valve stem a little bit shorter.)
4 pcs $48US
I wouldn't give CycleX 1 cent of my money.
Must be a story behind this I don't know about  ::)

Offline HondaMan

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Re: Finally rebuilding my CB 750
« Reply #123 on: June 12, 2024, 09:51:12 PM »
Seat done.



I like the stealth engine in this one.
:)
See SOHC4shop@gmail.com for info about the gadgets I make for these bikes.

The demons are repulsed when a man does good. Use that.
Blood is thicker than water, but motor oil is thicker yet...so, don't mess with my SOHC4, or I might have to hurt you.
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Link to Hondaman Ignition: http://forums.sohc4.net/index.php?topic=67543.0

Link to My CB750 Book: https://www.lulu.com/search?adult_audience_rating=00&page=1&pageSize=10&q=my+cb750+book

Link to website: www.SOHC4shop.com

Offline Leino

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Re: Finally rebuilding my CB 750
« Reply #124 on: June 23, 2024, 05:25:15 AM »
Seat done.



I like the stealth engine in this one.
:)
Yes! Several of my bikes share the same technology  ;D