Author Topic: Yankee Doodle not so dandy CB400 rebuild  (Read 2026 times)

Offline Nurse Julie

  • 1973 CB750 UK K2.1977 CB550/4 Mongrel Brat. 1978 CB400/4.
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Re: Yankee Doodle not so dandy CB400 rebuild
« Reply #45 on: October 06, 2018, 01:04:23 PM »
Im putting half a hand up as I never new the spring and ball were there until we had an in depth discussion on here about what made the 'click'  when moving the lever up and down. I was ready for the little blighters when I took mine apart.
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 Skunky

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Re: Yankee Doodle not so dandy CB400 rebuild
« Reply #46 on: October 06, 2018, 01:39:55 PM »
Still, The carburettor rebuild is nearly complete. All the carbs have been scrapped scrubbed and cleaned in an ultrasonic cleaner, tops and bowls polished, new jets needles and seals fitted and reassembled. Then Disassembled as the light dawned on the missing spring. A manual set up bench set up to get it as close as possible to factory and then should be able to get a start. One tip I could pass on. I managed to rescue the floats but the pins were of course ruined. I bought a 2mm model makers brass rod from fleabay for £2.99 for 200mm and cut my own pins rather than pay £2.50 each for them. Still got enough for another rebuild  ;D. Got my eyes open for a set of Vacuum gauges but in no hurry.
Honda CB400F USA
Triumph Thruxton 900
BMW K100 Custom Buils

Offline Skunky

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Re: Yankee Doodle not so dandy CB400 rebuild
« Reply #47 on: November 15, 2018, 06:43:39 PM »
Hi Honda lovers, It’s been a long time since my last confession. I finished the carburettor rebuild some time ago and it’s been sitting in the garage calling to me.
Before I start the strip down, I wanted to gauge the engine condition. As previously mentioned the engine turns over and has compression. I put the carbs back on hooked it up to the car battery and tried to start. She popped and spluttered and then

https://youtu.be/CKfXo_9H4Lo

The Engine doesn’t sound too bad for a 44 year old.
Honda CB400F USA
Triumph Thruxton 900
BMW K100 Custom Buils

Offline rozabikes

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Re: Yankee Doodle not so dandy CB400 rebuild
« Reply #48 on: November 15, 2018, 10:34:39 PM »
Nice one. Great feeling when they first fire up!
One day I'll have the time to restore it, not just talk and dream....

Offline Skunky

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Re: Yankee Doodle not so dandy CB400 rebuild
« Reply #49 on: March 30, 2019, 09:28:01 PM »
Hi Honda lovers

Spring is in the air and I have returned to my CB400 project, which to be honest has been languishing in the garage since October. I had some work to do on my Triumph and still have some to do on my beemer.

Anyway, last year I got the Honda running and was happy with it. The Engine has good compression and ran well.
Today I stripped the Honda down to the frame . Everything came apart well engine out, forks, wheels even the loom.

I turned the frame over to remove the stand and that’s when I discovered a massive problem. When I bought the bike I noticed some iffy looking welding on the side stand. I assumed that it may have had a problem and been botched. Seems I wasn’t wrong😢.
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Honda CB400F USA
Triumph Thruxton 900
BMW K100 Custom Buils

Offline Nurse Julie

  • 1973 CB750 UK K2.1977 CB550/4 Mongrel Brat. 1978 CB400/4.
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Re: Yankee Doodle not so dandy CB400 rebuild
« Reply #50 on: March 30, 2019, 09:33:32 PM »
😱😱😱😱😱
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 K2-K6

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Re: Yankee Doodle not so dandy CB400 rebuild
« Reply #51 on: March 30, 2019, 09:41:14 PM »
Whoa, it's not often you see such a classic example of pigeon-shit welding  :)

Or perhaps even worse and verging on hemorrhoids.

That's not good is it.

Offline Skunky

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Re: Yankee Doodle not so dandy CB400 rebuild
« Reply #52 on: March 30, 2019, 09:41:46 PM »
😱😱😱😱😱

I know. Should have heard the language 🤬🤬. I have a welder/ fabricator who has done work for me before. I shall take it to him to see if it can be salvaged. If not I either look for a frame or scrap and sell the parts.
Honda CB400F USA
Triumph Thruxton 900
BMW K100 Custom Buils

Offline Moorey

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Re: Yankee Doodle not so dandy CB400 rebuild
« Reply #53 on: March 30, 2019, 09:45:29 PM »
It looks like all the original bits are there. A grinder and a competent welder will sort that easily enough.

Offline Skunky

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Re: Yankee Doodle not so dandy CB400 rebuild
« Reply #54 on: March 30, 2019, 10:07:58 PM »
In going to go over the frame tomorrow cleaning and de-rusting just to make sure there's no rot. I think a P.O. Must of hot the side stand really hard. Luckily the frame seems true so it should be OK
Honda CB400F USA
Triumph Thruxton 900
BMW K100 Custom Buils

Offline Andych

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Re: Yankee Doodle not so dandy CB400 rebuild
« Reply #55 on: March 30, 2019, 10:39:28 PM »
Wow... that makes my side stand area look good... relatively speaking...
Actually... looking at my pic again.. I think they are almost on par..

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1975 CB400 - Project
1978 Yamaha SRX250 - Project

Offline Skunky

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Re: Yankee Doodle not so dandy CB400 rebuild
« Reply #56 on: April 05, 2019, 01:20:08 PM »
Today I’m a much happier Skunk 😁
Picked up my frame from my welder in Derby and he has done a great job [ Guests cannot view attachments ] [ Guests cannot view attachments ] [ Guests cannot view attachments ]
Honda CB400F USA
Triumph Thruxton 900
BMW K100 Custom Buils

Offline Laverda120

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Re: Yankee Doodle not so dandy CB400 rebuild
« Reply #57 on: April 05, 2019, 03:25:54 PM »
Very nice job. You are back on the road to recovery. Keep the progress photos coming.
If the welder is willing to take on this type of work it might be a good idea to post his details on the parts and services section?
1976 Honda 400/4
1977 Honda 400/4
1981 Honda CB250RSA
1977 Rickman Honda CR750
1999 Honda VFR 800FX
1955 750 Dresda Triton
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1982 Laverda 120 Jota
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Offline SumpMagnet

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Re: Yankee Doodle not so dandy CB400 rebuild
« Reply #58 on: April 05, 2019, 06:47:51 PM »
Considering what your welder had to start with...he has done a good job of recovering that!
CB750F2 - in pieces
CB900F Hornet - the daily transport

Offline Lobo

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Re: Yankee Doodle not so dandy CB400 rebuild
« Reply #59 on: April 06, 2019, 12:33:17 PM »
...the bigger the blob, the better the job.
Surely... 😂