Removing 190km/h speed cut on jap spec/grey market bikes vfr 750

Right.. As some of you may know from my earlier posts I was havin serious mid-top end power issues where my 1990 vfr 750 would run perfect till about 4-5000 rpm and it would big Down (feel like no power). The reason was because the previous owner claiming to be an "electrical engineer" re-loomed the bike for reasons I do not know of.. Because the original loom other then being hacked apart by him.. Looked fine. So I re-loomed the bike properly, as I have adequate automotive electrical knowledge as do the rest of you most probably.. Now I was left with one orange & blue wire coming from the CDI UNIT which he had just left hanging in the breeze, because being a jap spec vfr, my Haynes manual didn't cover this model and didn't have the extra (13th) wire in the wiring diagram. Right so most of you will have original unmolested wiring and original clocks to boot, now if you have an rc35e engine like mine (jap spec) or a grey market bike, this orange & blue wire goes to the optical sensor in the back of your speedo housing, so when the speedo needle reaches 190km/h it blocks the signal therefore cutting power to the CDI UNIT via this orange and blue wire, this causes the CDI UNIT to retard the ignition timing and limiting power until you fall below this speed. YOU CANNOT SIMPLY CUT THIS WIRE !! You have to fool the CDI unit into thinking the sensor is still there by soldering in a 3ohm resist between any 12.0-12.6 v power supply and the orange and blue wire .. Essentially removing speed cut properly. If you just cut the wire the CDI will limit your power to 4-5000 rpm before retarding the ignition timing. Hope this helps some people who want to build a track bike or whatever.

 

Interesting, i replaced the entire wiring harness on this bike. I took care not to hack up the old one, its sitting on a hook next to my pole trimmer. Bike runs fantastic, but then agai, all of my stuff runs güt. Cheers, thanks for sharing that

 

Some of them have a sensor in the actual speedo kind of like a hall sensor that can be moved within the actua lhousing to remove the speed cut

Some models need a plugin unit between the speedo and the loom plug

I had a Japanese model VTR1000f when I was in NZ and it was a simple plug in box complete with loom plugs up in the head fairing

 

My Japanese market 1997 VTR1000F had a single pink/green wire screwed onto a terminal on the back of the speedo; I pulled that off and, hey presto, no speed limiter.

 

Hey guys, in reply to all, some models will be easier then others to convert of course. My issue was I had a home job wiring loom with loose and stray wires everywhere.. No original clocks, and the guy had just snipped the CDI wire and with nothing on the Internet and no manual covering this particular wire I was lost for a while haha.