Yamaha Tach Problem

[Petty Cash]

I have twin 2001 Yamaha 200hp, HPDI's. The Yamaha digital Tachs work OK, except the engine trim guages work erractically. When I first turn on the igition and the tach goes thru it's diagnostic routine, everything looks fine. When the engines are running and the port engine is trimmed up, the trim guage is erractic. It never goes over 2 bars of the 12 bars on the display. The starboard tach also is mostly on 2 bars. Sometimes the starboard trim guage goes up to 4 bars when I'm trimming up the engine, but that's all, then it finally reads 3 bars. The engines trim normally. Everything else on the tachs work well. Any ideas on how to fix this?

 

[rodbolt]

Re: Yamaha Tach Problem

hello<br /> spray fluid film on the senders. the senders on those motors liked to stick. keep them sprayed. the sender cam likes to break as well. its a potentiometer it varys the resitace for the pick off voltage that is sent back and converted to the bars you see.<br /> good luck and keep posting

 

[Petty Cash]

Re: Yamaha Tach Problem

Do you have to take the covers off to see the senders or are they outside the motor?

 

[rodbolt]

Re: Yamaha Tach Problem

hello<br />the senders are mounted on the swivel bracket. if you look on the steering tilt tube you will see the sender cams. the cams are just plastic rings with a screw and an arm that drives the sender. the sender is held on with 2 #3 phillips screws. but usually we can free them up and replace the sender cams and all is well.<br /> good luck and keep posting