something is screwy abt my new tach

[chrisdoc0608]

i just got a tiny tach, well not that brand but very similar. anyway i installed it like the directions said and started up my ski, to my suprise it said the idle was at 3400-3600..... so then i reved it up and it went a little over 9k :dunno:
i thought those numbers were extremley high even though i dont have a rev limiter and it was out of the water but idk so i thought i would ask to see if i wraped it worng or something... heres a pic of what i did

 

[marz831]

When I used one, I would wrap it further away from the boot and put about 1/4-1/2 inch between coils.

 

[SuperJETT]

Are you sure it's for a 2 stroke and not a 4 stroke? Sounds like idle is reading double which would be the case since a 2 stroke 2 cylinder fires the plugs twice/revolution.

 

[chrisdoc0608]

i am 99% sure its for 2 stroke. i will go check in a min. but that still would mean that my peak rpms were 4500 if it was doubled for a 4 stroke.... which i know isnt right.

 

[Crab]

www.tinytach.com

 

[WaveDemon]

it's doubling it. not only is it a 2 stroke but it fires every stroke. divide your rpms by 2.

 

[SuperJETT]

If you're just blipping it on the trailer, it won't see full rpms long enough to truly show the reading.

I'd first adjust the pickup, an inch or so away from the plug boot, and play with the turns from 3 to 5 normally gets it with a TinyTach, and if that's not it, then it's possibly a 4-stroke or 3-cylinder 2-stroke model that is only expecting one spark per revolution.

 

[chrisdoc0608]

i forgot to post this last night, but it is definately a two clyinder twostroke model... so it shouldnt be double

 

[njfl]

i forgot to post this last night, but it is definately a two clyinder twostroke model... so it shouldnt be double

On OEM 62T, 64V/X, 61X, and 6M6 Yamaha ignitions a waste-fire setup is used where both plugs fire every time. This is why I always suggest that people swap their plug wires to see if problems follow the wire, or stay on the same cylinder.

Since each plug fires every time, you will see a doubling of RPM reading.

 

[chrisdoc0608]

well that blows.... so this tach will not even be able to read my peak rpms bc it only goes a little over 9k and i know my peak are above 6500-7000+ so i basically just wasted 40 bucks

 

[SuperJETT]

well that blows.... so this tach will not even be able to read my peak rpms bc it only goes a little over 9k and i know my peak are above 6500-7000+ so i basically just wasted 40 bucks

have you played with the number of wraps and position of the pickup wire yet?

 

[chrisdoc0608]

not yet, im abt to go ship out a flywheel and nozzle to lpw then when i get back i will try