Tachometer Teleflex with Johnson 115 1998

[aclmvh]

I believe the tach for my '98 Johnson 115 is fried- it worked before, but stopped working with no prior notice- Here is what I have done to test, so please, anyone make suggestions. It's a Teleflex 8k RPM International Series and my 115 has a rectifier....no regulator.
1. Tach zeroes when I power on the ignition- my VOM says I have over 12.5 volts DC at the tach IGN and NEG poles.
2. I have a good ground- no resistance when I check the tach NEG pole to a good ground on the boat.
3. With my VOM connected to the tach NEG and SND poles and the motor running, I get good and correct variable AC voltage based on motor speed.
4. I have checked the rectifier based on the shop manual instructions and it checks out.
5. One thing I haven't done is short the tach SND pole to the tach NEG pole (Teleflex says the needle should go to the max position). I will try this.
6. Oh, and the calibration on the tach is 6P....which is correct for a 2 stroke Johnson V4.
That tells me "get a new tach" unless someone has another suggestion.

Thanks,
MVH
Jville/FL

 

[jtexas]

Re: Tachometer Teleflex with Johnson 115 1998

I concur.

and welcome to iboats!

 

[aclmvh]

Re: Tachometer Teleflex with Johnson 115 1998

Well I got a new tach- same model Teleflex. Problem solved.

mvh
Jax/Fl

 

[Chris1956]

Re: Tachometer Teleflex with Johnson 115 1998

Jax, Just so you know, your motor is supposed to have a watercooled voltage regulator as std equipment.

 

[aclmvh]

Re: Tachometer Teleflex with Johnson 115 1998

That surprises me- the shop manual says that some of these engines came with unregulated charging systems with rectifiers. Anyway, the new tach has done nicely for the past year.

mvh
Jax/Fl