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My 1975 CB400F US
petermigreen:
I received a big box of parts this week so have made some progress but I still feel a long way off just yet :'(
Managed to get all the cables and pipes hooked up to the carbs and straight away noticed petrol overflowing out of 2 and 3 so out with the carbs again and replaced the float valves and re-set float heights. Felt prudent to test on the bench before refitting.
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So back on with the bowls and back in the bike, after spending what seemed like an hour trying to 'encourage' the float bowl gaskets back into their recess!! That's like some kinda fricking Chinese puzzle!! Happily though carbs are no longer overflowing.
I'm now in the situation where the engine starts fine and runs but I'm way off on the carb adjustments and I'm even struggling to set a decent idle as the revs seem to rise and fall randomly. Very rich judging by the plugs and smoke coming out of the silencer also.
I have bought some vacuum gauges but am a long way off getting to that fine tuning stage.
Also, the tacho seems to glide up and down rather than follow the true engine revs if that makes sense. Not sure this is correct but it's a brand new cable and it's free so a bit confused about this.
Any carb tuning experts out there??
In addition to the carb woes, I've got no clutch either, that is to say that I don't think the mechanism is making contact with the clutch as there is no resistance at the lever whatsoever.
Also received notice that the VJMC honda dating officer has received my application so the registration process is in motion.
mike the bike:
There's a coarse clurch adjustment under the triangular plate on the clutch cover.. It sounds like that needs tweaking.
petermigreen:
Update -
Been a bit of an eventful week and I had to walk away for a few days to gather my thoughts.
I've had the carb bank back off the bike and whilst on the bench the fast idle cam fell off its spindle! Happens to be lucky as it made me realise why my choke mechanism wasn't behaving as it should.
As I was at the VJMC day at Ace Cafe on Sunday I took the opportunity to get a good look at the mechanism on a tidy 400/4 on the VJMC club stand and got a few photos for reference.
So choke mechanism repaired, carbs re-stripped and rebuilt with all new jets, O rings etc. and all datums reset. Got them back on the bike last night and balanced tonight and bike now singing like a bird. Beautiful.
With the engine tuned I decided to drain the oil and remove clutch cover so I could solve the lack of clutch issue. Turns out the course adjustment screw was corroded into the mechanism which is why I couldn't adjust it in the usual way. That's now cleaned and fettled and I now have the clutch back in action.
Very satisfying as all the major problems are now overcome I have an MOT booked for Saturday week and my dating letter is now with me. So after MOT I'll be able to send off to the DVLA for my historic bike age related registration.
You never know I may just get a ride or two in before the leaves fall. 8)
petermigreen:
Clutch sorted so couldn't resist a quick test run to make sure it all checks out.
https://www.youtube.com/watch?v=rXdxi6wLJEY
Very pleased.
(Yes I did miss 2nd gear :-[ cos I was just so excited ;D)
Nurse Julie:
How exciting and I see you have one of those invisible number plates ;D ;D ;D
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