150 Verado overheats above 2800rpm

breausaw

https://youtu.be/TydI3L9jqi0

See above video, motor would overheat above 3800 rpm. Temp would rise above 210 and tiger alarm and digital overheat screen on Mercury smart gage, would actually reduce RPM automatically. After about 2 hours went back to normal. ..steady 148 to 152.
Thinking sticky thermostat, so replaced. 20 hours later same thing 80 miles from port, think I know the fix but just thought I'd through this out there. BTW, water pump recently replaced and water pressure on gauge within factory specs.
Could make about 15mph, just hope engine not damaged.
Called Mercury outboard customer service from remote Village of Chiniga in sawmill bay on Cell, actually got ahold of someone that seemed to know what they were talking about, told me what would most likely be the problem.
Called local dealer but was not able to talk with mechanic, even offered to pay shop time for time spent discussing issue.
Not something you necessarily want to happen that far from Port, did not seem to worsenson so did a bit of fishing before heading back.

BrentB · Posted: Mon Jun 13, 2016 10:20 am Post subject:

I cant view the video due to security block

Are the thermostats defective when testing in hot water or full of debris and clogged?

BrentB · Posted: Mon Jun 13, 2016 10:35 am Post subject:

Does the thermostats seat flush into the block or is corrosion present?

BrentB · Posted: Mon Jun 13, 2016 10:49 am Post subject:

Does it have a poppet valve or pressure relief valve? It is spring loaded valve in the water cooling systen and designed to maintain water pressure at low rpms to help out the water pump then opens at higher rpms and the water pump can provide adequate water flow. Should it fail and not open or is clogged, it can restrict flow at higher rpms. On Yamaha, they un screw and easily accessed from the outside on the midsection leg

Also a sensor might be bad

Good puzzle

journey on · Posted: Mon Jun 13, 2016 11:15 am Post subject:

Well, the rest of us are guessing. What did the factory rep say was the problem? Relieve our curiosity.

BTW, given the info you've told us, the factory is the most likely to know the answer, in my opinion.

Boris

breausaw · Posted: Mon Jun 13, 2016 12:00 pm Post subject:

BrentB · Posted: Mon Jun 13, 2016 1:29 pm Post subject:

Even a blind squirrel finds a nut once in a while

breausaw · Posted: Mon Jun 13, 2016 9:51 pm Post subject:

breausaw · Posted: Thu Jun 16, 2016 5:27 pm Post subject:

When I picked up the poppet valve from the dealer had a chance to talk with the mechanics and got the impression it wasn't going to fix my problem, and it didn't.
So three-day fishing trip planned for this weekend cancelled. Took the boat to the dealer and left it, hopefully they will have a look at it in 3 or 4 days.
Truly a bummer, weather is awesome and the fishing is hot.
Oh well guess I'll catch up on some of my honey dues.
Will post updates when I know more.
Thumbs Down

BrentB · Posted: Thu Jun 16, 2016 11:00 pm Post subject:

bummer

breausaw · Posted: Fri Jun 17, 2016 2:15 pm Post subject:

Weather turned snotty so don't feel so bad, hopefully have it out of the shop by next weekend and after I stuff a plug of money in the proverbial hole.

BrentB · Posted: Fri Jun 17, 2016 2:46 pm Post subject:

fyi in case you have not seen this site

http://www.veradoclub.com/

AK Angler · Posted: Mon Jun 20, 2016 8:18 pm Post subject:

It's possible that salt deposits are constricting flow or even blocking water passages. Do you flush regularly with Salt Away or a similar product?

breausaw · Posted: Mon Jun 20, 2016 9:47 pm Post subject:

BrentB · Posted: Tue Jun 21, 2016 8:39 pm Post subject:

Simple solenoid testing SOP

http://www.arcomarine.com/xhtml/Tech%20Solenoid%20Circuts%20%26%20Testing.pdf