I’m looking to run a Rotax kart with a GPS lap timer only (AIM Solo). Is it necessary to have the RPM and Water temp gauge? I know the engine has a 14k limiter and I’ve read the cooling system is stout. I figure the engine will tell you if its geared wrong and you’ll know if its overheating because of power output.
You could run without a tach or water temp, but. The timing goes away after a certain rpm but there is no limiter. Start with an axle gear that’s too small and add teeth rather than over gearing it and turn to too many rpm’s. An engine that’s too hot or cold is not going to make max horsepower.
If you feel comfortable without a tach and temp, go for it. How do you plan on jetting the carb?
P.S. There are going to be many used MyChron 4’s available.
I’d definitely want the H2O sensor in there… I’ve seen a few Rotax Max engines suffer major (expensive) damage from overheating that could be avoided, mostly due to lack of water or circulation (forgetting to put water in; a leak in the system – either hole in the rad or poorly connected hoses; or a bad internal water pump – maybe from leaving water in when it freezes). Running with less that ideal cooling (too much tape on the rad) generally won’t cause major damage, but will cause a decrease in performance.
I could live without a tach – let the stopwatch be your guide on that… however the tach wire is the cheapest part of a mychron, so I don’t see why you wouldn’t hook that up.