Author Topic: CB750 K0-K6 4-4 exhaust. Assemble them without excessive force or denting them  (Read 1567 times)

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Offline PeWe

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I noticed when I mounted my 4-4 exhaust on the bike that it can take time when the pipes are not completely in bottom of the exhaust spigots on the head. It is not possible to mount the long bolt holding the passenger foot peg and both pipes into the frame.

This due to the pipes, one or both you are working with had glided a few mm off the spigot. The only thing now is to remove the rear bolt, swing pipes down and let the front pipe bottom into the exhaust spigot. It is not possible to hammer them in place since the angle of the spigot will lock them if the rear bolt is mounted. Force will most likely dent the pipes!!!

A strap around the engine keeping both pipes in place is one way doing it, strap and tighten when both pipes are mounted as deep as possible in their spigots. Then swing them up aligned with the frame and hole for the rear bolt. Mount the long bolt with foot peg that still might be a little bit tight.

I did it today again, this time photos for others that will mount new or old 4-4 and might have forgotten/dont know how it can be done.

I started with 2, then 1.  2 must be inside of the sidestand.
One detail that can cause problem is the rubber hose connecting the rear ends of pipes together. This can be done afterwards with a heat resistant water or oil hose, cut opened and mounted, wrapped aorund afterwards. Strapped into place with a hose clamp or plastic strap.

Last doing 3, 4 on other side. I tighten the exhaust clamps when in place and rear is tightened. Not overtight these clamps! They will collapse and threads will be damaged. Dont ask me how I know ;)
« Last Edit: February 06, 2017, 11:04:01 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 Old Scrambler

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Nice set of JUGS................good advice.............while twisting and wiggling each pipe into place, I sometimes help things along with a rubber mallet near the spigots ;)
Dennis in Wisconsin
'64 Triumph Cub & '74 Honda CB750 Bonneville Salt Flats AMA Record Holder (6)
CB750 Classic Bonneville Racer thread - http://forums.sohc4.net/index.php/topic,135473.0.html
'63 CL72 Project(s)
'66 CL77 Red
'67 Triumph T100C
'73 750K3 Owned since New
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Offline ekpent

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  So that new hypo sets of jugs apparently does not use he old stock style cam chain adjuster PeWe??  looks clean back there without it.

Offline Don R

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 I was wondering if new copper o rings would be helpful, then finish tighten the flanges last? Last time I tightened nothing until it was all together. I have a set due mid week so I'll report on them when I can. Bike is on the lift ready to go.
 
 I used Eastwoods inside the pipe stainless header paint. Hopefully that will extend the life a little.
No matter how many times you paint over a shadow, it's still there.
 CEO at the no kill motorcycle shop.
 You don't need a weatherman to know which way the wind blows.

Offline PeWe

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Original cam chain adjuster is there, as usual. The fat flanges catch the eye :)
A CB900 DOHC starter motor is hidden under the chrome cover. It pulls very strong. I should not have any idea about that mod without this forum!
« Last Edit: February 04, 2017, 03:36:48 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 PeWe

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About copper o-rings for exhaust. Some will flatten out into the port. Tighten spigots and grind off the excess of copper. I had a little and thespigots have some to remove too. I did not port the spigots, mine have improvements to be done.
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 ekpent

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 Oh yes I can see it now in the picture but yes my eyes were full of fat pretty fins  :D Anxious to hear a ride report, should be quite the sleeper beast !

Offline Sgt.Pinback

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Japauto cylinder?
Doc, I love a motorcycle!

Offline RAFster122s

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JMR (Mike Reich's) handiwork 1000cc billet block I believe.
David- back in the desert SW!

Offline PeWe

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Japauto cylinder?
This JMR Billet Block (designed and fabricated by forum member MRieck) reminds med about the Japauto bikes I have seen. They used Honda 4-4 too :)
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