Author Topic: CB400F  (Read 599 times)

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Offline madcb400f1

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CB400F
« on: May 02, 2020, 08:28:49 AM »
Hi all, looking for some help. 1975 CB400F losing spark on cyl 1 and 4. replaced battery, rectifier and reg with ricks combo. replaced coil (5ohm), spark plug leads and plugs. Will run on all four cylinders for about a mile then only on 2 and 4. Thank you.

Offline bryanj

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Re: CB400F
« Reply #1 on: May 02, 2020, 08:29:51 AM »
Condenser and or incorrect points gap
Semi Geriatric ex-Honda mechanic and MOT tester (UK version of annual inspection). Garage full of "projects" mostly 500/4 from pre 73 (no road tax in UK).

Remember "Its always in the last place you look" COURSE IT IS YOU STOP LOOKIN THEN!

Offline madcb400f1

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Re: CB400F
« Reply #2 on: May 02, 2020, 08:37:30 AM »
forgot to add electronic ignition

Offline bryanj

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Re: CB400F
« Reply #3 on: May 02, 2020, 10:27:27 AM »
In that case your electronic ignition is duff
Semi Geriatric ex-Honda mechanic and MOT tester (UK version of annual inspection). Garage full of "projects" mostly 500/4 from pre 73 (no road tax in UK).

Remember "Its always in the last place you look" COURSE IT IS YOU STOP LOOKIN THEN!

Offline Kevin

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Re: CB400F
« Reply #4 on: May 02, 2020, 03:09:26 PM »
I'm guessing it's an old style Dyna S.
They heat up and then cut out.
The new Dyna S looks to be much better made.
 I haven't had problems with the new style units but have with the older ones.

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A couple of 400F's and a
'98 Suzuki Intruder VS1400 ~ for long rides

Offline madcb400f1

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Re: CB400F
« Reply #5 on: May 03, 2020, 09:29:38 AM »
Thank you all for replies, ordering new part

Offline madcb400f1

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Re: CB400F
« Reply #6 on: May 09, 2020, 09:39:43 AM »
New ignition fixed problem, thank you all again.