200 tachometer

When does it peg the tach ??? At half throttle ?? or very near the end of the throttle lever stroke??   Most tach's of that design I've been around usually peg the needle at100%  full throttle. is it right ?? Not really, but it seems to be that way on a lot of them. Worn alternator pulley will make it worse.

Is it one of those new Chinese ones?

F Y I, pulley on a 200 should be 3 1/8" diameter and using 1/2" wide belts.  I'd bought a used alternator at salvage yard that had 3 1/2" pulley on it, tach did not read right. .

I'm sure you've already done it, but is all wiring in the right place? And are the grounds properly cleaned and tight? Is there a way to isolate the alt. and see what it is sending to the gauge? Let us know when you find the problem.

The tach drive is on the back side of the alternator. I did notice that the when I idle back the tach is slow to response. I'm starting to think that the problem is in the new tach.

Take your tach drive gear housing off your new alternator and make sure it has the correct drive gears in it.  I think it's suppose to be 45 teeth on the larger gear and 12 on the smaller gear.  Some have been put together with a 43 tooth gear and this will throw the RPM's off on the tach.

Ok I tore that back off the tach drive and the the big gear has 43 teeth and the small gear has 14 teeth. Where do I go from here. So I call Sandy lake implement and see if they will make it right or is that the way they come out now. Up for suggestions.

I went down this road with a 170 diesel. Bought a "new" tach from aftermarket source and did not register correctly. Thought about the gears, cable and all that stuff. Finally, I read an article on a guy who restores tachometers. His name is Haim Zeevi. He rebuilt these for a living and now is retired and does it part time. His work is excellent! He knows everything and I mean everything about tachometers. I called him explained what I had, and he said send it down and I'll have it done in 2 weeks. He even was able to put the hours I wanted back on the tach. I cannot say enough about the quality of his work He also rebuilds cables, gears, etc. He said that the new tachs are made with plastic gears and usually fail around 100 hours...so rebuild is a much better option. I received my tach back with a new cable and it looks and work flawlessly.
His contact information is: Haim Zeevi 386-569-5284

How does the gear in the alternator get changed? Does it just slide in or is there more to it? I think our alt.guy got a small gear for a Massey(reads the wrong RPM'S). Thanks

ranger42 wrote: I went down this road with a 170 diesel. Bought a "new" tach from aftermarket source and did not register correctly. Thought about the gears, cable and all that stuff. Finally, I read an article on a guy who restores tachometers. His name is Haim Zeevi. He rebuilt these for a living and now is retired and does it part time. His work is excellent! He knows everything and I mean everything about tachometers. I called him explained what I had, and he said send it down and I'll have it done in 2 weeks. He even was able to put the hours I wanted back on the tach. I cannot say enough about the quality of his work He also rebuilds cables, gears, etc. He said that the new tachs are made with plastic gears and usually fail around 100 hours...so rebuild is a much better option. I received my tach back with a new cable and it looks and work flawlessly. His contact information is: Haim Zeevi 386-569-5284

****X2. Rebuild the originals.  And Haim warranties his work. In our conversations he confirms what I hear, that most of the cheaper tachs usually don't make it past a few hours.  I am aware of Dealers selling the knock off's and that didn't work out too well either.  acplowboy45, care to share where you got the tach and how it plays out??  Thanks...Dale