Question about spark revolutions on a 85HP 1989 Force

[Karla45]

I am installing a Tiny Tach on my boat. In order to set it correctly I need to know how many sparks per revolution for my motor. For instance 3 sparks per revolution and so on. I have no idea how to figure this out.

 

[maverick974]

Re: Question about spark revolutions on a 85HP 1989 Force

One.......

 

[Karla45]

Re: Question about spark revolutions on a 85HP 1989 Force

Forgot to add that I have 3 cylinders and the motor is two stroke. I guess I was thinking maybe it had to do with how many cylinders I have on my motor, so I kind of thought it might me 3 sparks per revolution.

 

[jamwad]

Re: Question about spark revolutions on a 85HP 1989 Force

You should have it connected to a spark plug wire, not the coil wire... The plug will fire once per revolution. But yes the coil would fire 3 times.

 

[fucawi]

Re: Question about spark revolutions on a 85HP 1989 Force

just so you all get educated

A ONE STROKE ...Fires at the top and bottom of of each stroke ..used on two cylinder 2 stroke engines with one double ended coil.
A TWO STROKE .. Fires at the end of every other stroke ....this is in fact how most of the cars you drive fire even if they are 4 stroke in there combustion cycle..its called wasted spark..Briggs and Stratton and all small 4 strokes fire like this as well as your car. A V6 with 3 coils .......

A FOUR STROKE .. Fires every 4 strokes ..not seen very often restricted to vehiciles with distibutors and contacts of the 1970 -1980 vintage .....

Do not confuse the fireing pattern with the combustion pattern ..does not have to be the same ...

 

[roscoe]

Re: Question about spark revolutions on a 85HP 1989 Force

Yes you have 3 sparks per rev, but the signal pick up wire from the tinytach only picks up a signal from 1 sparkplug lead.

 

[fucawi]

Re: Question about spark revolutions on a 85HP 1989 Force

Having sold thousands of the units you are using ..NOTE ..use the bottom plug and keep the wire away from other wires on the engine ....square black unit two buttons S1 and S2 ..not waterproof ..and the plastic on the front will crinkle up in the sun ...if it stars flashing 000000 11111 22222 the battery neg has come disconnected ( 10% of production) ......even so I made a fortune !!!!

 

[Karla45]

Re: Question about spark revolutions on a 85HP 1989 Force

okay thank you for the heads up on that