Wiring issue for replacement tachometer

[SteveG54]

Can any help me cure a problem with my 1999 Yamaha 60FETOL 2-stroke? I've swapped my old 6Y5-2818 tach for a 6Y5-8350T-82-00. I've connected it using the replacement trim/oil harness and wired it as per instructions found at mbcboats.com. I've also set the switches as instructed. However, when I start the engine the RPM indicates half of the engine actual RPM, and the Oil alarm doesn't work properly. When there is hardly any oil in the tank no alarm sounds, but as I pour more oil in the alarm sounds and the indicator for low oil flashes on the gauge. I have tried the switches on the back of the tach in every combination and it doesn't change either fault. If anybody has any suggestions as to how I can get things working as they should be I'd be very glad to hear them. I have replaced thetrim/tilt gauge lead with the new 2 wire set up as well.

Thanks from Steve G

[boscoe99]

Can any help me cure a problem with my 1999 Yamaha 60FETOL 2-stroke? I've swapped my old 6Y5-2818 tach for a 6Y5-8350T-82-00. I've connected it using the replacement trim/oil harness and wired it as per instructions found at mbcboats.com. I've also set the switches as instructed. However, when I start the engine the RPM indicates half of the engine actual RPM, and the Oil alarm doesn't work properly. When there is hardly any oil in the tank no alarm sounds, but as I pour more oil in the alarm sounds and the indicator for low oil flashes on the gauge. I have tried the switches on the back of the tach in every combination and it doesn't change either fault. If anybody has any suggestions as to how I can get things working as they should be I'd be very glad to hear them. I have replaced thetrim/tilt gauge lead with the new 2 wire set up as well.

Thanks from Steve G

This may be part of the problem. A 1999 60 HP two stroke uses a three wire sender. Why did you not use the correct sender?

Some analog tachometers use a relay. The digital tachometer does not. Is your engine connected to the tachometer using the trim/oil harness that has two ivory coloured nylon connectors at each end? Is that harness positioned correctly? It has an engine end and a tachometer end.

See diagram below regarding the tachometer settings.