I have 1999 that has done me well the past 5 years I’ve owned it.
Recently when I go above 3000 rpm I get an alarm that throttles me down with no warning on digital gauge(temp/oil). Nothing flashing.
I have replaced water pump, thermostats, water sep, and fuel filter on motor. I have ran w/o cowling and oil and fuel levels stay normal. Still same problem.
Can anyone assist?
Thanks!
Sounds like temp
oil or temp
just because oil is good, sensor may not be
take the motors temp externally
I will check.
Where is the best place on engine to take temp?
What should temp be?
ok, I finally got out this afternoon with an infrared gun and both heads are running 170F when alarm sounds so problem found. Now, where to go from here? I have new thermostats and water pump was changed last Nov. and I’ve only put about 20 hours on it. I guess I’ll inspect pump to make sure all is good there. What else could cause overheating?
THANKS!
Try running without the T-Stats,sometimes they stick closed.
Double D.
not likely both tstats are sticking
did you install a YAMAHA waterpump or an aftermarket one, also did they put in a kit or just an impeller
sounds like a watersupply issue to me
Did you find out what it was?
Sea Hunt 202
Yam 150
Replaced water pump with YAMAHA kit last Nov. So, I pulled it today and had some sand in it so cleaned it out and impeller still had plenty of spring left to it. Hope to get out tomorrow and test. I guess I’ll run w/o Tstats next…
take t-stats out
leave open
run engine with fresh water on hose to flush out system
OK.
Got out today and both heads were running 125F at idle and 160F at 3000rpm when alarm went off according to infrared gun. Chris, you said the operating temp should be 140F. I’v read the switch is set at 180F for overheat alarm. Thinking I should test temp switches in each head. Do these things just pull out? What are the specs?
What about the thermo switch at the bottom of starboard head…can it be tested?
Thanks for input.
I’ll also flush w/o thermosts.
Thanks Chris.
160 is to high, so checking the sensor really doesn’t matter at this point
you need to get the temp down
Flushed w/o thermostats with fresh water. Went ahead and kept them out and ran it yesterday. Ran @ 3500rpm for 30 min and no alarm. Heads were reading 130F-135F. Got home and tested the month old stats in pot of water and they opened just fine. I hope it was just crud that was flushed out. I will update when I put stats back in.
Thanks for the update and post what you find when you put the t-stats back in. I had the same problem on a 130 Yamaha.
Sea Hunt 202
Yam 150
they should of been much cooler than 135 without t-stats
t-stats should bring temp UP to 135-140
if there was sand in the waterpump, you likely have grooves cut in the housing and wearplate
is the pee stream a solid straight line going to the ground, or does it have an arch in it?
The pee stream does have a little arch to it. I did notice some very shallow grooves beginning on wear plate. When I flushed w/o t-stats, should the water have cleared the head because it pretty much just ran down the side. It sounds more and more like a pump issue. I guess I need to try a new housing…
Working my ARS off…finally got back out today. Put t-stats back in and overheated again @ 3000rpm.
Summary:
Can run below 3000 w/o overheating.
Water pump less than 10 hours on it.
New thermostats.
Does not overheat when I run w/o t-stats.
Could it be anything else other than pump?