Spark Plug Gap

I just cant see the gap being what the manual says on a 1982 KZ750-M1 CSR Twin it states the gap should be 0.7-0.8MM SO I thought that my plugs were gapped wrong. I re gapped the plugs to what the manual says but the bike will not run at idle and smokes like a freight train. I gap them to .020 Thousandths and it runs fine. Could someone tell me what the correct gap is because I just dont think this book is correct it has to be a misprint. At 0.7 - 0.8 the plug is almost closed to the electrode no place for a spark to occur. Thanks for any help.

Post edited by: dadams7161, at: 2007/06/09 23:50

You do realize that 0.7mm is .028 thousndths of an inch, and 0.8mm is 32 thousandths of an inch, right? So, by gapping them at .020" you are reducing the gap?

.020" is entirely too small of a gap.

Post edited by: steell, at: 2007/06/09 23:58

steell wrote:

You do realize that 0.7mm is .028 thousndths of an inch, and 0.8mm is 32 thousandths of an inch, right? So, by gapping them at .020" you are reducing the gap?

.020" is entirely too small of a gap.<br><br>Post edited by: steell, at: 2007/06/09 23:58

OK because the numbers on my feeler gauges between those sizes is so thin that you could put a piece of paper an measure it I never was to good with metric anyway I just read the numbers and go.

Post edited by: dadams7161, at: 2007/06/10 00:28

For conversion there is only a couple that you need to remember, you can figure out the rest.

1mm = .040"
1 inch =25.4mm
0.125" = 1/8"

Ok, three of them

went back out and re gapped them it is fine but ran about the same. Thanks Steell

Post edited by: dadams7161, at: 2007/06/10 01:17

It will run better under load at higher rpms with the larger gap. Your bike has electronic ignition, and that helps
My 79 750 twin has an 82 750 CSR motor in it, but I filled in the smog ports and used the 79 cam cover.

why not put new plugs in, they are cheap and will make it run better

BSKZ650 wrote:

why not put new plugs in, they are cheap and will make it run better

they are new plugs

Just a thought but when you close the gap it increases spark intensity making the bike run leaner if it is running rich. If you increase the gap it makes it run richer. Maybe your over fueling and dont now it. I remember way back before when my enrichening valves were leaking it wouldnt run good unless I had .28 or less gap, and this is with dyna coils and updated wires. Now that Ifixed the enriching valves I have opened the gap to .035 thousands and have new found power at top end. Plugs are tan color too, something I never had with the enrichening valve leaking.

Also check the voltage going to the coils, mybe your not getting enough juice to fire a gap of more than .020