81 dohc coil/ignition upgrades

[brugmand]

Hi guys,

Running murray carbs, d8ea plugs, mk2 b6 coils, stock harness, resistorless caps, and delkevic exhaust

I found some ignition issues with my 81 cb750 and as a temporary fix I dropped in coils from a mk2 bandit 600 which I had lying around and bypassed the signal wire to coil 2.3.

The bike is now running on all 4 with strong spark but the spark is inconsistent, testing with a strobe light it will will spark consistency then won't trigger the strobe light for a second or 2 then fire back up again.

Could this be caused by the coils having the wrong ohm resistance ? I'll be replacing them anyway so if anyone has coil recommendations thay would be awesome!

Also the bike has very low power at low rpm, like it will stall under 3k or 4k very easily and breaks up around 7 or 8k

 

[animaljim]

Hi guys,

Running murray carbs, d8ea plugs, mk2 b6 coils, stock harness, resistorless caps, and delkevic exhaust

I found some ignition issues with my 81 cb750 and as a temporary fix I dropped in coils from a mk2 bandit 600 which I had lying around and bypassed the signal wire to coil 2.3.

The bike is now running on all 4 with strong spark but the spark is inconsistent, testing with a strobe light it will will spark consistency then won't trigger the strobe light for a second or 2 then fire back up again.

Could this be caused by the coils having the wrong ohm resistance ? I'll be replacing them anyway so if anyone has coil recommendations thay would be awesome!

Also the bike has very low power at low rpm, like it will stall under 3k or 4k very easily and breaks up around 7 or 8k

One thing I found with mine when it was doing something similar to that is the rubber plugs in the float bowl to block off the one Jet access were leaking so I put oring on it and it fixed it. Sucks that I took it to two different motorcycle mechanics and they couldn't find this but it worked out