1969 Evinrude 55hp RPM Tach Question

[Texmill]

I need to check the RPM's on my old Evinrude, but it doesn't have a tach. I have a dwell meter that we used on automobiles long ago. How/where would I attach it to this motor to read the RPM's. It has two lead w/clips, one read and one black?

 

[F_R]

Re: 1969 Evinrude 55hp RPM Tach Question

Sorry, it won't work.

The permanently mounted tachs for that motor count the AC pulses from the alternator. Shop tachs generally have an inductive pickup that senses the pulses in a spark plug wire.

EDIT: Thinking about it for a minute, it occurs to me that that motor was a bit peculiar. It was wired for a special tach that worked off the ignition amplifier. Those tachs have long ago disappeared from the market. To use a modern one, rewire it to the alternator and set it for 6 pulses.

 

[Tim Frank]

Re: 1969 Evinrude 55hp RPM Tach Question

Had the Johnson version.
Never hooked up a tach to it, but the wiring was there from the engine up to the ignition key for connection.
Not sure if that is any help.

 

[Texmill]

Re: 1969 Evinrude 55hp RPM Tach Question

I actually got a vitage Tach off ebay, looks almost identical to my speedo, and it only has a grey & back wire.. it has old 55 listed on the instruction sheet. I'll hook it up and see what happens, I need to figure out how to mount it, since I don't have much room on the dash.

 

[Texmill]

Re: 1969 Evinrude 55hp RPM Tach Question

I hooked my tach up this weekend and took her out to the lake. The instruction sheet that came with tach only went back to 1971 on the Evinrude, but said to set for pulse 5. However, even at aprox 27mph, it only registered about 2500 rpm, when it should have been about 4500.

I tried changing to different pulse settings but only caused it to show lower rpms. Anybody got any ideas?