Rexmar and cp sell the standard dealios, as for small- if you can not find it at those places, check your local dirt bike shop- some company makes them for race bikes, I think they will work on any motor- they are little digital jobbers-

i have one you can have-just pulled it out of a boat that i cut up=if not graingers in west sac will have one

Can it be zeroed?  Where and when can I get it?   Greg

correction to last post =the meters i have down at work are 120vt-so they wont work my error