Yamaha 4.3l YEMS - WOT problem

[cbahash]

Hi All,
I have a 1991 Kayot 18 with a Yamaha 4.3l Yems in it and I don't want to sink it. The motor will drop down to 2400 rpms out of the blue. I think it is electrical. Just rebuilt the raw water pump, checked thermostat, rebuilt carb and a new fuel filter.
Any thought would be appreciated!
Chris

 

[CaptnKingfisher]

Hi All,
I have a 1991 Kayot 18 with a Yamaha 4.3l Yems in it and I don't want to sink it. The motor will drop down to 2400 rpms out of the blue. I think it is electrical. Just rebuilt the raw water pump, checked thermostat, rebuilt carb and a new fuel filter.
Any thought would be appreciated!
Chris

Sounds like it's ignition circuit related, like suddenly you lose a cylinder. When the problem occurs, does it last awhile? Hopefully it lasts long enough so you can do some diagnostic work. Next time it occurs I would use a pair of insulated pliers and try a cylinder drop test. Intermittent issues are a pain in the a**. Also put your hand on the ignition coil when it happens, is it hot