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Old 06-27-2007, 09:40 AM
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funola funola is offline
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Join Date: May 2005
Location: NYC
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How did you cool the motor with the hose? My guess is your tach fix is temporary.

Have you taken any measurements at the tach amp? Pin #'s should be labeled on the socket. 2 is gnd, 6 is + 12V, 7&9 is mag pickup and should be around 80 ohms power off. 3 is output to tach. Wrap a short length of solid thin gauge wires around pins 3 and 2 of the tach amp, bring it out (tape up to make sure no shorts) and measure with a DVM on the AC scale. At 750 rpm idle, you should get between 0.2 to 0.4volts. This is the pulse output to the tach from the tach amp. If you get no voltage at all on pin 3, then possibly the mag pickup is bad, or the tach amp is bad, or wiring is bad, or the mag pickup gap is way off, or the single tooth (approx 1/8 dia 1/2 long) on the HB is missing..

Last edited by funola; 06-27-2007 at 09:46 AM.
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