Honda-SOHC

SOHC.co.uk Forums => CB500/550 => Topic started by: Rolfbulmer on July 19, 2022, 04:30:11 PM

Title: 550F2 not firing on cylinders 1 & 4
Post by: Rolfbulmer on July 19, 2022, 04:30:11 PM

So it was with great delight that I started the engine for the first time today - brilliant it sprang into life. But before I could really congratulate myself I discovered that cylinders 1 & 4 were not firing.
I have done no investigative work yet. Was wondering if anyone could give some tips on the most likely cause and the order and best way to start checking things please.
PS the engine was run 'remotely' with the bare minimum wiring required.

Title: Re: 550F2 not firing on cylinders 1 & 4
Post by: SteveD CB500K0 on July 19, 2022, 04:40:18 PM

1 & 4 are fired by the same coil so first place to look is the 12V feed from the points to the coil.


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Title: Re: 550F2 not firing on cylinders 1 & 4
Post by: Rolfbulmer on July 19, 2022, 04:46:04 PM

Thanks for the reply.
Simple lad that I am, how can I do this test, bearing in mind the bike has no ignition and battery.

Title: Re: 550F2 not firing on cylinders 1 & 4
Post by: K2-K6 on July 19, 2022, 05:05:06 PM

Inspect very carefully the assembly of wire on the 1/4 points as none of the metal components should touch the base structure of the points at that place.

The bolt and the wire tabs should all be insulated by fibre washers to prevent this happening, any missing fibre or the tabs bent such that they are touching the points baseplate and the system won't fire.

Check through carefully and compare to 2/3 to see if any obvious problem is there.

Also that both coils have a positive feed from the battery definitely in place.