Topic: cb650 custom, just fitted 2 new coils but not running properly. Help...

[jessie x]

Cb650 custom
1980
4 into 2 pipes

Hi all,

I have just fitted 2 new coils to the bike but I dont think it is firing/running correctly.

The bike starts perfectly, all 4 manifolds get hot quickly as they should but when you look at the exhaust the left pipe hardly has any gasses/smoke coming out of it whilst the right pipe has plenty of blueish smoke as usual. The left pipe is hardly making any noise compared to the right pipe.

The bike was running great before I fitted the new coils.

I have checked that I connected cylinder 1+4 to the left side coil and 2+3 to the right side coil.
Also that the wires are on the + and - on the coil  correctly. ie, black/white wire goes to the + on the coil etc.

I have a spare set of spark units which I have tried but it makes no difference.

Any ideas

 

[weltzing]

put the old ones back on lol, why did you change them if it was running great before?

[manjisann]

+1 to weltzing's question, what was the reason for the change if the others were working?

Also, pull the plugs on each cylinder and see what you can find. The bluish smoke sounds like oil burning for some reason. Check for spark on the plugs, although if all 4 headers are warm I'd imagine they are all firing.

Start from the basics, have you done a full tune up like the manual says? I know it's super annoying to hear it, but do that. i once spent 3 weeks chasing down a "coil" problem only to find out I'd hooked the gas line up to the breather tube on the carbs, so 1-4 were getting plenty of fuel and overflowing and 2-3 were dry.

Do the tune up and report your results, along with the original reason for the coil change, and I'm sure we can sort it out.

Brandon