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wrote:

Anyone know where to hook up a tachometer on a 73 Johnson v4 115?

I want to see where we are at. Make sure we are not over/under
propped. Also if anyone knows what RPM it should be at WOT would be
great also. What RPM planed out should one get the best Fuel miliage
out of it? I am guessing 3500 rpm. But being as how this is a barge it
never truly planes out I dont guess.

Thanks

The loose gray wire in your remote is the tach pulse lead.

The 1973 115 is rated at 5000 rpm, and even on a pontoon/barge you
should turn this at wide open for best economy, driveability, &
longevity. It will probably require a 15" pitch prop, though. It is
hard to say what speed is the best... most likely at idle to 1000 rpm,
and then all downhill from there.

Rob