Yamaha 130 Alarms

[SamP]

Hi, I have twin 1989 Yamaha 130s, I have an alarm going off and safe mode at higher RPMs after a few mile run. Water pumps have been replaced in the last year or so and I have a good telltale. My mechanic was in the boat at the end of last year and said the motors are not getting hot and that I have a bad sensor so I tested the sensors in a pan w/temp gauge and all close around 180-190 degrees. I don’t think the motors are getting hot and I cant seem to isolate which sensor is going off so this last Saturday, I ran the boat hard to get the temps up and when the alarm came on I stopped the boat and checked the heads immediately with a IR Gun and the temps across the heads where (127 & 111, 88 & 90 Degrees F)

So at this point I can not figure out why the alarm is going off and the motors are not hot?

Any input would be appreciated.

Thanks

[jb123]

pumps have been replaced..... in the LAST YEAR or SO ?? they should be done yearly.
have you also done your stats and prv's ??

i would do those first then look into cleaning your water jackets.

[jonp]

I had the same issue, turned out to be a broken vain from the impeller stuck in the water tube. Drove me nuts. Changed the sensor, water pump. Would run for fine while no problem, then sometimes after just a few minutes the alarm would go off... If you drop the LU again check that tube.

Good luck

jon

[jonp]

After reading this a bit more you may have a broken or intermittent connection somewhere. Since it’s a 1989 model, the wires and connectors could be suspect particularly if used in salt water.

The Best Jon

[SamP]

Jon,
Thanks, Its driving me nuts. even after the alarm goes off I can hold my hand on the block with no problem. and the temp readings on the IR gun prove its not getting hot. I will continue to trouble shoot. I just hate to throw parts at it.

Anymore ideals would be appreciated

Thanks