RPM Gauge on 2002 90hp Yamaha whacky

[h2orampage]

I recently purchased a 2002 17ft Sea Pro with a 2002 90hp Yamaha. The RPM gauge jumps up and down erratically, but the engine itself runs great. When off, the RPM gauge shows about 1200. Does this sound like the RPM gauge is shot, or could there be some kind of grounding or wiring issues? Any way to test?

 

[robert graham]

Re: RPM Gauge on 2002 90hp Yamaha whacky

the connections on the back of the tach need to be clean and tight. there is a small slotted screw on the back with about 3 or 4 different positions, like 1,2,3,4. your engine/tach set-up requires that screw to be in a certain set position. maybe you can reach back with a light and small screwdriver and change the settings back and forth until you get the correct reading. if you can't get back to it, then just take it out of the dash, wire it up and screw with it out where you can see what you're doing. I put in a new Teleflex tach a while back and i think it gave that screw setting in the instructions according to the motor. Good Luck!

 

[rodbolt]

Re: RPM Gauge on 2002 90hp Yamaha whacky

quite a bit of those hulls were rigged with NON yamaha stuff.
if your tach face has Faria printed on it replace it.
faria is italian for junk.
my 20 seapro came from seapro with a sweet 200 HP HPDI in 04 but it was rigged with junk.
sold the 200.installed an 07 F150 with command link and its a happy boat now.

 

[halas]

Re: RPM Gauge on 2002 90hp Yamaha whacky

Check your voltage regulator. I am new to the Zuki but the Johny's rpm reading comes off the rectifier or voltage regulator.