EST vs YEMS are they different?

[xxTheJokerxx]

When I look up parts for my Yamaha stern drive, I can choose 5.7EST or 5.7YEMS. What does that mean? Does it have something to do with instrumentation? I ask because my depth finder & fuel gauge as the only ones that are accurate. The tach reads 2000 rpm low, temp is 85? cooler, and oil pressure is 5% of what my mechanical gauges under the 'hood' are telling me. Thanks.

 

[Bondo]

Re: EST vs YEMS are they different?

When I look up parts for my Yamaha stern drive, I can choose 5.7EST or 5.7YEMS. What does that mean? Does it have something to do with instrumentation? I ask because my depth finder & fuel gauge as the only ones that are accurate. The tach reads 2000 rpm low, temp is 85? cooler, and oil pressure is 5% of what my mechanical gauges under the 'hood' are telling me. Thanks.

Ayuh,... I believe the differences are in the Ignition, 'n possibly the Induction systems used,...

I'd guess the issues with yer gauges are Ground issues,...
Start at the (-) terminal of the battery, 'n make sure ALL the connections are Clean, shiny metal Clean, 'n Tight,...
Then grease 'em, 'n they'll stay clean, 'n tight,...