Timing Light Issue - Insulated Plug Wires Blocking Timing Light RPM Pickup?

[westernco400]

I decided it was time to check my Vape timing static angle on my 1976 RD400 (stage 2 Scott Clough motor with Zeel unit/curves, pipes etc). My new timing light is a Innova 5568 (used to borrow one years ago) and it refuses to pick up my RPMs. I have what I believe are 2010 - 2015 era Vape wires and run resistor plugs. Can these coil to plug wires be so insulated they can't be picked up?

Also, if someone has an RD400 curve for a modded bike they have tested and like, please share it. I am getting a little knock at above 7500K due to 4500ft altitude and 91 octane gas here in Colorado so I will need to reduce my advance a bit.

[1976RD400C]

This is the curve of a oem Yamaha RD400 cdi that Canada/Europe? had. I wrote in the dial indicator numbers. My HPI is set about 2 degrees more advanced that this with 100 octane.

[m in sc]

I have an older vape. ive had issues with innovation lights, they like to freak out a bit. too sensitive, try flipping the timing light pickup over

[westernco400]

Anyone have a timing light that works on our RD coil wires that still might be available for sale?