8mm Spark Plug Wires?

[rockslide]

I ordered up a set of new spark plug wires assuming that 7mm were the correct wires. I just found out that my 1977 650 has 8mm wires on them ... 7mm are the proper stock wires - right? My new 7mm wires are way to small for the screw on coil caps ... hoping they'll let me return the 7mm's. These bikes didn't come with 8mm wires did they?

 

[XSLeo]

Mine are 7 mm. The hole in the cap is just a bit over 8 mm. I guess they did that so an 8 mm wire will fit. The hole in the coil is just under 8 mm. So the 8 mm is too big there.
I think where the wire fits the coil is more important. Check that.
Leo

 

[angus67]

i had to shave my 8mm to fit in the boots, tight fit in the coil, too

 

[gggGary]

I think the cap is designed to tighten against the compression donut that goes on the plug wire. It tightens and seals the joint, like a plumbing compression fitting. An o-ring or two would probably do the same job.