I cranked up my Merc 135 optimax in the yard this morning and ran it at idle for about 15 minutes. Everything was working perfectly. I then proceeded to launch the boat at our local ramp. I idled out into the river, adjusted the trim and accelerated. I got the overheat alarm before the boat got on plane. No water pissing out. Waited to get towed back to the landing. Do any of you experts have any idea what is wrong with this engine (aside from being a merc)?
oc
water pump! Dirt dobber in the line!
No expert but, Did you leave the flushing cups on it? Was it peeing when you let it idle? I have had good service with merc’s myself.
‘87 Pacemaker 31’ SF
‘04 Renegade 29’ 2 225’s
‘97 Maycraft 17’ 40 hp
It was peeing just fine and the water pressure was good on my gauge. Temp was normal. I guess it knew that my grandkids expected a boat ride this weekend.
oc
Try clearing out your pisser line with some replacement weed eater line. I’ve also had much success clearing mine out using compressed air, you may have gotten it clogged at the ramp. If that’s not it you probably have to get your water pump replaced.
Like filzfishin said, you can also disconnect the pee line from inside the cover and see if you have a blockage there.
‘87 Pacemaker 31’ SF
‘04 Renegade 29’ 2 225’s
‘97 Maycraft 17’ 40 hp
Same thing happened to me. It was my thermostats. On the Merc’s the thermostats are before the pisser. If the thermostats fail they don’t let any water pass. On the opti it is recommended to keep the thermostats. On the carbed motors it really doesn’t matter in this climate. Hope this helps.
Oyster Cracker, any luck?
‘87 Pacemaker 31’ SF
‘04 Renegade 29’ 2 225’s
‘97 Maycraft 17’ 40 hp
Nope, I bit the bullet and took it to an authorized stealer.
Please let us Merc fans know what it is when you find out. I am running the first Merc and love it.
It was the water pump. Had to be completely replaced. The whole assembly was shot.
oc
Thanks for the follow up and hopefully its running perfect for you now. What year is your optimax and is this a first water pump change I assume?..Just curious.
Glad you are back going.
‘87 Pacemaker 31’ SF
‘04 Renegade 29’ 2 225’s
‘97 Maycraft 17’ 40 hp