RE: Tachometer
I first started out with a Magnum tach. Never had any problems with it until I loaned it to one of the guys to "get a reading" on his helicoptor rotor. He got it a but close and the rotor took it out of his hand sort of crunched it. He bought me a Globee as a replacement. Lots more features, but the one thing it won't do is give me a good measurement on RPM. Every now and then, it will show my 52 OS four stroke cranking 23000 at half throttle. When one of the LHS went under, I picked up another Magnum and have been a happy camper since. It has the option of 2 or 3 blade props and that's all, and it works. Lilttle cheap 9V batteries that last forever if you remember to turn it off when you are done.
Don