Not Running on 4 Cylinders

[Eljay]

Hi All I have a December 1969 K0 which I have totally rebuilt on engine and frame parts. But I cannot get it to run on 4 cylinders. I have cleaned the carburettors / jets umpteem times and fitted new floats correcly fuel level adjusted. I have fitted new coils, new leads, new plug caps and checked that I get sparks at the plugs. Also checked sparks at the points. Wiring seems correct but when I try to start it, it usually fires up on cylinders 2 and 3 the central cylinders. I know it has fuel as I am using an external tank that I can see level dropping in.

The plugs on 1 and 4 spark when tested by cycling the starter but after insertion, nothing fires up.on 1 and 4.

When I bought it in California it had a 4 to 1 exhaust system fitted which I have changed back to the original 4 pipes. I would have thought that even if it was over or under jetted I would at least get a fire up in 1 and 4.
Could it be a faulty capacitor.? I am at a total loss, Need help please.
Best Regards
Les from Italy

 

[brettp]

I don't have your generation of bike, but if you're not getting spark on 1and 4 but the points are good, it is time to dive into testing that coil. If it passes then you test the part before that (spark unit / capacitor). Nice up the ignition system line until you find it.
Hopefully the gurus chime in shortly.

 

[icandothat]

Cylinders 1 and 4 are connected electrically. 1 and 2 are connected by fuel. So, if you're having trouble on 1 and 4 it's an electrical/spark problem.

Double check you set your timing correctly, make sure you have good condensers.

 

[drgnrdr750]

First make sure the coil is wired in correctly if so then put a sparkplug on the end of the wire and manually open and close the points for that plug and look for a spark. If no spark then the coil is no good.