Re: Tiny-Tach
Nothing special about it - you just need the one designed for 2-stroke motors. The 4-stroke model will actualy work but will read your engine's rpm x 2.
One thing you should know, however, is that Tiny Tach recommends not trying to splice wire onto their wire leads. This could mean that the stock length provided will not be long enough to mount the tach on your dash. If so, just tell them how long the leads need to be for your application and they will custom make a unit for you.