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CB350/400 / Progress - She runs at last! (75 CB400F)
« on: October 31, 2016, 01:59:07 PM »
So, big progress for me. After 20 odd years since it's last road tax, I have got her ('75 CB400F) started for the first time since my top end rebuild! Thanks to all that have reponded previously.
IT STARTS!
Literally on the button, first attempt, with Choke open or closed. Very happy about this! However I'm far from out of the woods.
- Appears to be running very rich (all plugs immediately / consistently blackened)
- Revs increase dramatically when I try to open the choke.
What's changed since my last attempt:
- Carbs stripped and rebuilt (again), bodies simmered in a pan for an hour or so with a dishwasher tablet, then recleaned with parts cleaner spray and went over all ports blowing and checking (concentrating on idle circuit).
- Re-Bench synced them, this time doing it in the 'closed position' rather than open. Used a 4mm drill bit as it was what I had to hand, maybe I should have gone for 3mm as closer to the 'interweb recommended' 1/8".
- Also rechecked/adjusted Tappet clearances, Points Gaps, and Static timing.
So, any thoughts on what to do next?
- Check timing with timing light now I can run the engine.
- Redo carb Static balance?
- Idle screws?
- Try the OEM Idle jets back in there now the bodies are cleaned.
- Fit Hondaman transitorised ignition box (likely unrelated, but i'll fit it anyway)
Or is this likely to be something more fundamental, ie Rebuild kit jets not correct? Carbs bodies still not clean? REv counter isn't working, so not a clue what
At the very least this has renewed my enthusiasm so i'm keen to keep the momentum up!
Dave
For info, my previous thread: http://www.sohc.co.uk/index.php/topic,9575.0.html
IT STARTS!
Literally on the button, first attempt, with Choke open or closed. Very happy about this! However I'm far from out of the woods.
- Appears to be running very rich (all plugs immediately / consistently blackened)
- Revs increase dramatically when I try to open the choke.
What's changed since my last attempt:
- Carbs stripped and rebuilt (again), bodies simmered in a pan for an hour or so with a dishwasher tablet, then recleaned with parts cleaner spray and went over all ports blowing and checking (concentrating on idle circuit).
- Re-Bench synced them, this time doing it in the 'closed position' rather than open. Used a 4mm drill bit as it was what I had to hand, maybe I should have gone for 3mm as closer to the 'interweb recommended' 1/8".
- Also rechecked/adjusted Tappet clearances, Points Gaps, and Static timing.
So, any thoughts on what to do next?
- Check timing with timing light now I can run the engine.
- Redo carb Static balance?
- Idle screws?
- Try the OEM Idle jets back in there now the bodies are cleaned.
- Fit Hondaman transitorised ignition box (likely unrelated, but i'll fit it anyway)
Or is this likely to be something more fundamental, ie Rebuild kit jets not correct? Carbs bodies still not clean? REv counter isn't working, so not a clue what
At the very least this has renewed my enthusiasm so i'm keen to keep the momentum up!
Dave
For info, my previous thread: http://www.sohc.co.uk/index.php/topic,9575.0.html