project boat tach problem

[phil123]

my project boat is finally finished with one exception. I bought a used tach (Honda) from a surplus marine supply. I know it's connected properly and the pole switch is in the right place for my '82 johnson 35. However, tach doesn't work. It lights up and the hour meter works, but no tack reading.
Is there a way (short of buying another tach) to test the gray signal wire to see if in fact it's transmitting a signal?

 

[asm_]

Re: project boat tach problem

You not going to like this answer.... Yes, the but the alternative is going to cost you more - a scope Should be able to pick one up around $1000.

B

 

[phil123]

Re: project boat tach problem

can i borrow yours?

 

[FuriousMob]

Re: project boat tach problem

You should be getting something like 5.5v AC on the gray send wire while at idle and it will increase as you increase RPMs. You should also do rectifier and stator tests. Use the Joe Reeve's Tach test in the sticky, or Google for it.