95 200 Johnson Tach and trailer loading ?

[rost495]

2 seperate questions.

First, I have a tach, its on old boat and used motor. I have the sender wire running to the engine but have not made time to find out which wire to connect it too....
I ran the boat and motor in the lake for the very first trial run today. Noticed the tach works??????? Went from zero up to 6500+ while at WOT... How or whats happening?

Second, STEEP ramp, boat ran fine all afternoon, but while loading on trailer as boat went up trailer at angle, the motor was down low in the water and acted like it had NO power and died... ?????

Thanks in advance.

Jeff

 

[ezeke]

Re: 95 200 Johnson Tach and trailer loading ?

The floats in the carburetors close the float valves when the engine is not in the normal running position. You need to keep the A/V plate within 15 degrees of parallel to the water or you will run out of gas.

The tach lead is in the engine harness leading to the control and the tach connection. It should not need or require a separate lead.

 

[rost495]

Re: 95 200 Johnson Tach and trailer loading ?

Thanks, makes sense on the angle now.
As to the harness, this is a big rigged up deal, there isn't much left of the old harness, I have a seperate sending wire thats not connected to the harness, IE the tach has its power supply etc..... and then the sending wire, that sending wire is just laying in the engine compartment now. I wouldn't know how the harness can help as its not connected to the tach.

Thanks, Jeff

 

[HighTrim]

Re: 95 200 Johnson Tach and trailer loading ?

What exactly is wired then regarding the tach? As Ezeke said, you do not need a separate sending wire, it is in the harness.

 

[ezeke]

Re: 95 200 Johnson Tach and trailer loading ?

If the wiring is following convention, there is a gray wire running from the regulated, water cooled rectifier to your main engine harness then on to the tach. Many side-mounted controls had a 3 wire socket for the tachometer that you could just plug in. This gray wire is the sender for the tachometer.

The tachometer gets power from the ignition switch like other gauges so it would have a purple wire and black ground wire from there.

 

[rost495]

Re: 95 200 Johnson Tach and trailer loading ?

Tach has a light wire, blue, a power wire purple, and a ground wire, black. THen it has the other post for the sender, that wire was not intact so I ran a new 16 ga wire for it, whatever color I had, and its in the engine compartment, figured I'd figure out how to connect it as I get everything tweaked up.

Much like trying to find 1/8 NPT heat sensors for my heat gauge, same thing there, power, ground, lights but nothing to connect to.. of course it doesn't work yet..

Thanks, Jeff

 

[Dhadley]

Re: 95 200 Johnson Tach and trailer loading ?

As you drive the boat on the trailer the nose goes higher and the motor goes deeper in the water and fills the exhaust cavity higher than normal which increases backpressure on the exhaust. The result is that you will have less power when trying to accelerate.

Ever notice how guys with hydraulic jackplates run them to the top when loading? Not just for prop clearance.........