I have spent the last week trying to get my Vapour reading rpms correctly! The ppr values are easy once you get your rpms stabilised. At first I hooked up Vapours power supply to that of old speedo which is fine, the mistake I made was running a common ground back through original speedo ground. I couldn't get rpms stabilised, so then I removed rpm sensor ground and ran it solo to frame. This seemed to work at first, it seemed to have stabilised rpms. When I started the bike the next day the rpms seemed to be all over the place again. I started to think it was where I installed the rpm sensor, I connected to plug after coil instead of between coil & spark plug. I really didn't want to take tank and all back off so I was going to run rpm sensor to spark plug lead to see if it would work there. But first I decided to try removing the power ground, this has been successful in stabilising rpms once these were stable it was easy to set ppr. Here is how, if rpms are reading double what they should then set ppr to 2, if you are reading half what rpms should be set ppr to .5 this is where I have set mine. Just about to take for another ride to see if OK will report back if any problems. . Grant
