Author Topic: 1975 400/4 project  (Read 4517 times)

Offline Sprocket

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Re: 1975 400/4 project
« Reply #75 on: July 10, 2019, 08:45:36 AM »
So the engine is buttoned back up! No massive problems putting it back together. Last evening I cleaned up the exhaust studs and put the good ones back in. One was 'short' and one was an M6 bolt, so I've ordered replacements.
Looking forward to cleaning up the carbs, I have a Crusinimage kit I'll be breaking open in a couple days. Few jobs left to do before I fit the engine; new rear tyre, paint the rear wheel spokes, repair the master cylinder as it's puked it's guts all over my floor....
Then I think the real work starts!

Offline Laverda120

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Re: 1975 400/4 project
« Reply #76 on: July 10, 2019, 11:04:04 AM »
Good progress Sprocket👍.
I have the master cylinder to rebuild on my 400/4. That's going to be fun, the hardest part is removing the circlip. I modified an old pair of circlip pliers to do the job on the m/cyl a couple of tears ago.
Keep the photos coming.
1976 Honda 400/4
1977 Honda 400/4
1981 Honda CB250RSA
1977 Rickman Honda CR750
1999 Honda VFR 800FX
1955 750 Dresda Triton
1978 Moto Morini 350 Sport
1982 Laverda 120 Jota
1924 Triumph 550SD
2012 Stanley Battery Drill

Offline mattsz

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Re: 1975 400/4 project
« Reply #77 on: July 10, 2019, 11:40:04 AM »
Good progress Sprocket👍.
I have the master cylinder to rebuild on my 400/4. That's going to be fun, the hardest part is removing the circlip. I modified an old pair of circlip pliers to do the job on the m/cyl a couple of tears ago.

I shed a few tears myself, trying to remove that circlip...

Offline Sprocket

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Re: 1975 400/4 project
« Reply #78 on: July 10, 2019, 11:53:41 AM »
I have two master cylinders, so I can practise and cock one of them up while I polish my technique!  :o

Offline paul G

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Re: 1975 400/4 project
« Reply #79 on: July 10, 2019, 12:18:51 PM »
Good progress Sprocket👍.
I have the master cylinder to rebuild on my 400/4. That's going to be fun, the hardest part is removing the circlip. I modified an old pair of circlip pliers to do the job on the m/cyl a couple of tears ago.
Keep the photos coming.
I did exactly the same thing just ground them down  :D
« Last Edit: July 10, 2019, 04:42:10 PM by paul G »
Honda CB400 4
Honda CB550 K3
Honda CB750 UK K1 restoration (Finished)
Kawasaki Z650 C2
Kawasaki Z650 cafe racer (ongoing)

Offline Nurse Julie

  • 1973 CB750 UK K2.1977 CB550/4 Mongrel Brat. 1978 CB400/4.
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Re: 1975 400/4 project
« Reply #80 on: July 10, 2019, 01:48:49 PM »
Looking good 👍👍👍
Im a Nurse, trust me, this won't hurt.....much !!!

LINK TO MY CB400/4 ENGINE STRIP / ASSESSMENT AND REBUILD...NOW COMPLETE
http://www.sohc.co.uk/index.php/topic,14049.msg112691/topicseen.html#new

Offline Sprocket

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Re: 1975 400/4 project
« Reply #81 on: July 16, 2019, 04:54:58 PM »
Not much of an update, but I did 'have' to turn it round in the garage last evening...

Offline Nurse Julie

  • 1973 CB750 UK K2.1977 CB550/4 Mongrel Brat. 1978 CB400/4.
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Re: 1975 400/4 project
« Reply #82 on: July 16, 2019, 05:01:39 PM »
She'll be up and running in no time now. Does look good. Have you tightened the lock nut on the cam chain adjuster?
Im a Nurse, trust me, this won't hurt.....much !!!

LINK TO MY CB400/4 ENGINE STRIP / ASSESSMENT AND REBUILD...NOW COMPLETE
http://www.sohc.co.uk/index.php/topic,14049.msg112691/topicseen.html#new

Offline Sprocket

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Re: 1975 400/4 project
« Reply #83 on: July 16, 2019, 06:30:37 PM »
It's tight but not adjusted. I think start and break-in will be ok with it as is, what you reckon?

Offline Nurse Julie

  • 1973 CB750 UK K2.1977 CB550/4 Mongrel Brat. 1978 CB400/4.
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Re: 1975 400/4 project
« Reply #84 on: July 16, 2019, 07:33:09 PM »
It's tight but not adjusted. I think start and break-in will be ok with it as is, what you reckon?
It should be fully adjusted before you start running in the engine. If the cam chain is flapping around in the tunnel, its not going to do it much good. Also, the chain on the sprocket wheel pulls the camshaft down in to optimum position, therefore it needs to be fully adjusted to make everything work as it should.
Edit...I should have added that you still need to check it is fully adjusted when the engine is running. But, I found that by adjusting it fully before, it wouldn't take any further adjustment anyway.
« Last Edit: July 16, 2019, 08:08:05 PM by Nurse Julie »
Im a Nurse, trust me, this won't hurt.....much !!!

LINK TO MY CB400/4 ENGINE STRIP / ASSESSMENT AND REBUILD...NOW COMPLETE
http://www.sohc.co.uk/index.php/topic,14049.msg112691/topicseen.html#new

Offline Sprocket

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Re: 1975 400/4 project
« Reply #85 on: July 17, 2019, 08:43:14 AM »
Ah right, the procedure in the book of words said to slack off the bolt (and let it adjust itself) when the engine was running. I suppose I could do that before I start it to get it most of the way there. I'm concerned the running in process is going to be a bit frantic enough though!

Carbs will have to be bench-balanced, sparks will have to be 'almost right' and hope everything holds together for 10 mins run!  :o

Offline Nurse Julie

  • 1973 CB750 UK K2.1977 CB550/4 Mongrel Brat. 1978 CB400/4.
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Re: 1975 400/4 project
« Reply #86 on: July 17, 2019, 08:56:11 AM »
Agree, the book of words does say that. But, once you get the bike fired up, the last thing you want to do is have it sitting running, getting very hot, whilst you fettle and adjust things. It's best to do as much as you can before even starting the engine for the 1st time, so you can ride away, getting air round the engine to keep the engine temp down. Fine adjustments to carbs, cam chain etc can be done when the bike is well run in.
Im a Nurse, trust me, this won't hurt.....much !!!

LINK TO MY CB400/4 ENGINE STRIP / ASSESSMENT AND REBUILD...NOW COMPLETE
http://www.sohc.co.uk/index.php/topic,14049.msg112691/topicseen.html#new

Offline Sprocket

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Re: 1975 400/4 project
« Reply #87 on: July 17, 2019, 08:57:44 AM »
:) Sheepishly looking forward to it now! Thank you!

Offline Nurse Julie

  • 1973 CB750 UK K2.1977 CB550/4 Mongrel Brat. 1978 CB400/4.
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Re: 1975 400/4 project
« Reply #88 on: July 17, 2019, 09:06:04 AM »
It will be very exciting for you. Dont do the first ride on a hot day. Just don't let her get too hot, I know you have new pistons and rings, so you need a lit of cool air around the top end to avoid over heating and seizure whilst running in. Just make sure when you fire her up that you have oil getting to the top end by removing a tappet cap at each end and watch for splashes / specs of oil. If you don't see this, stop the engine and investigate / rectify or you could cook your top end 😱😱😱
« Last Edit: July 17, 2019, 09:08:30 AM by Nurse Julie »
Im a Nurse, trust me, this won't hurt.....much !!!

LINK TO MY CB400/4 ENGINE STRIP / ASSESSMENT AND REBUILD...NOW COMPLETE
http://www.sohc.co.uk/index.php/topic,14049.msg112691/topicseen.html#new

Offline Bryanj

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Re: 1975 400/4 project
« Reply #89 on: July 17, 2019, 03:43:25 PM »
If you adjust it the way i did for all my years in the trade it will be OK to run for quite a few miles.
1 loosen lock nut
2 loosen lock bolt
3 put weight on kickstart so that you can feel engine about to turn over
4 whilst holding this position nip up lockbolt
5 let go kickstart and nip up locknut

This pulls the front run tight and has all the slack in the side with adjuster blade so if horseshoe free and decent springs on pusher it should be OK