5Th Gen Stick Coil Redux

First off, I want to acknowledge Rangerscott and Rush2112 on VFRD, and Mohawk here (and others) for the
original work done on the stick coils for the 5th Gen. All great work and I read dozens of pages of info.
I decided I wanted to use the CBR coils with the GSXR rubber caps.
So a month ago I bought set of 08 CBR1000 coils, and a damaged set of 04 GSXR750 coils of ebay, about $60. for all.
I set about test-fitting, measuring, comparing the coils and various components.
The primary resistance was 1.8 ohms for the CBR and 2.2 ohms for the GSXR. The secondary resistance
was ~12K for the CBR and ~18k for the GSXR. The VFR coil measured the same as the CBR.
When it came to fitment, I was surprised at the difference in length between the CBR and GSXR coils,
but beyond that, the GSXR sits very proud of the cover. The CBR sits much lower - and barely makes connection with the plug.


Actually, with the stock rubber seal, it doesn't connect at all. Only when I cut down the rubber seal
to a wide washer did it fit, but I wasn't going that route.


The GSXR seal on the CBR was barely better, but would barely engage with the plug top.
(overstretched cap on coil)

The GSXR seal cap is 2.5mm thick; the CBR coil was 1mm off the deck (lip of the hole)
when fully seated on the plug w/o seal. I needed ~10mm of rise to use the CBR coil and GSXR cap,
and have the coil fully seat on the plug.
So - what I needed was an extended plug top - which was easier to solve than I expected.
A 4mm thread - find a 4mm standoff - thank you Digi-Key! $5. for 10, nickel-plated brass, and 3 day delivery.


The plug thread length is 7.6mm, the standoff is 10mm long, the thread is 10mm long.
I calculated that I should cut 3-4mm off the end of the thread on the standoff to gain the
correct depth and seating for the coil. A slight tweak with pliers to tighten the standoff to the plug.


Assemble, connect, and test fire - works perfectly!


Again, not creating anything new here just another approach to running the CBR coils with the GSXR caps.
I felt it important to cover the plug hole to prevent dirt, sand, water, small furry animals from getting in there!

Cheers all!

 

Another old timer resurface :thumbsup:
Thanks for sharing your finding with us :wink: