1996 Yamaha Saltwater Series II 150

[citadel1995]

Hello everyone, I'm new here but have been reviewing the threads for a little while now.
I have my fathers 19-6 Aqua Sport and 1996 Yamaha Saltwater Series II 150hp V6. The motor has somewhere between 75-100hrs. I took it out last week and had hesitation issues and the RPM surges, I was reading through the posts about those problems and did all the fuel lines and filters stuff. I thought I would try the seafoam in the carbs before going further and now the motor is overheating. Has good water flow but its still running hot.Did I screw up by using the seafoam? should I replace the thermastats? They were just done last year. I would like a little guidance please on where to start so I do not waste time overthinking something.

Thank You!

 

[rodbolt]

Re: 1996 Yamaha Saltwater Series II 150

what RPM does the alarm sound?
what does the tach indicates show when the alarm sets?
if the carb jets are clogged your probably going to burn a piston long before the seafoam cleans all 6 main and all 6 idle jets.

 

[citadel1995]

Re: 1996 Yamaha Saltwater Series II 150

Thanks. Yesterday it sounded off at idle, tach said 8-9rpms. today I went to go pull t-stats, but thought before that I was going to turn it on and document the time and everything, but it idled for 30mins with no alarm and the engine was hot to the touch but I could hold my hand on the head, yesterday it was so hot you couldn't touch it at all. So my thought here is that it's cooling.

The tach was flashing the temp. icon when the alarm was sounding off. I can handle rebuilding the fuel pumps, but do not think I should attempt the carbs. the cleaning and rebuilding with the kits I could do but I know from experience I always screwup the adjusting/fine tuning once they are on. I rebuilt a yamaha 3 carb. jetski last year and could never get the carbs tuned just right and none of the local mechanics would offer any help.

Should I try just doing the pumps first and test to see if problems still exist or do both the pump and the carbs at the same time?

Thanks for the response!