MZ/MuZ Riders

Does anyone have any idea why my ETZ251's tacho doesn't register below 2k revs?

It's got a digital tacho, not one with a cable and drive gear on the end of the clutch.

It stays at zero then jumps to 2k and then it's fine above 2k. When the revs drop back to below 2k, it hits 0 again.

It's a bit annoying because I want to set the idle speed accurately....

Cheers,
Steve.

Well basically it is a novel idea to want to set an accurate idle for starters and secondly they were crap, but not as crap as the Skorpion ones. Can't think of any fix apart from a dirty pick up??

I cant be 100% helpful as my ETZ251 has a cable driven tacho....


but, the first thing I'd look at, is where the electronic tacho gets its feed from......
make sure its all plugged in properly, and the contacts are clean.....



however, there is another option I can think of.......
someone I know, had a small 2 stroke 50cc bike (non MZ) with an electronic tacho.
it had a battery, but it wasnt needed for the bike to work....his battery fell off (dont ask!), and he rode it around for a year without a battery.....

his tacho only worked over 3,000rpm when the bike created enough power to run on its own.......



so I'd also be checking the charging system and battery are working properly

Im going to check the contacts eventually.

The bike also has an electronic ignition, I'm not sure if it has an automatic retard/advance at low revs.... That could cause it as the tachometer works from the ignition coil.

I'm not too fussed if it never works properly, it doesn't affect the running of the bike.

my rt125 tach is driven off of the cdi box
and when its real humid here where i live its not always working proper

i am going to take it apart this winter and give the inside a good clean
as my wiring harness has the attack of the green slime monster
this river valley hates copper wire and Printed Circuit Boards

also a less than proper feed of electricity to the cdi box can cause the tach to read funny
some times check connections and fuse in the whole system if its a cdi driven tach
dave