Modern Vespa

hi again!my analog koso rev counter,is only giving me x2000 revs instead of x1000!!!
the back buttons have 2 setings.the first is 1,2,3,4 and the second is 1,2.that is when you press both buttons together,and you choose the correct setting..
the only right' setting seams to be 1 and 1.
but even then,is showing me x2000.the other combo settings are just screwed up!!
i know its corect if you subtrack 1000revs.
i am used to it right now,BUT..now that i wat to put on a malosi cylinder,the revs are finished,even with the 28 carb on,it reaches 7000,which is 14000 on mine!!!
i have conected 1 cable to the on/of switch,one grounded ,i used to have one on the positive of the battery,but i found out that its working the same without it so i took it of,and the one thats attached to the spark plug lead.
anyone knows what the problem is?thanks,merci,spasiba,efxaristw!

Are you using an after market ignition system like a Vespatronic? If so, you will need to dial in the correct rev setting. The manual explains all of it.

www.sip-scootershop.com/en/main/base/details/Download.aspx?ID=879006bd-7cf0-45e5-be37-ab1db898b0ee

no factory,its own,PX 200disc .its been like that since the begining 6 years ago,but now im about to run out of numbers!!!

Not sure where you're getting the signal for the tacho from but be aware that there are the 3 pulses per rev are due to the 6 magnets in the flywheel. A regular analog tacho actually reads 3x actual revs so not sure why your Koso is reading 2x.

oh..i thought it supposed to read x1000.sips tacho-rev counter which is koso by the way reads x1000 though..how?strange things..!

SIP tacho probably has a clipper diode of some sort specifically for the Vespa or it uses an inductive signal from the HT side.

I went through all this with a couple of cheap analog revcounters. The best solution is the SIP unit or the tacho from a Vespa Cosa.