AWOL

Ive done some researching on this site, ad of course google, and I'm looking for further input.

This a new development. The starboard exhaust has lower water volume exiting out the exhaust, and Im getting a lot more steam than usual. Ive checked the hoses for blockage, and I have a new thermostat on the way. Im not sure if that will remedy the problem, but its worth replacing anyway.

The boat stays under 150 on the gauge, and the water exiting the port side is cold as the water the boat is in. The other side, the riser is definitely warmer/borderline hot - but I can keep my hands on it for several seconds, even after a hard run or high idle for many minutes (seen in video).

I hope its just low water volume, not a larger issue. The plugs check out, no misfire.

Really, other than the excess steam, I wouldn't think of anything.

Here's the videos to help:

https://www.youtube.com/watch?v=mGCQ_zSBPpQ
This really gets me wondering why my boat doesn't run 160 degrees, like ever. It always sits around 125-130. Maybe the thermostat is stuck, or possibly not even there (first year with boat). If the two water temps were to combine, life would be good. I don't think I have the thermostat housing style with the check balls, but maybe Im mistaken.

Any help would be appreciated.

AWOL

https://www.youtube.com/watch?v=ID04nnzcO3c

SB

iTrader: (1)

Good videos. However, you just missed showing us what kind of t-stat housing is on it. Any pics ?

Edit in: Btw: Most carb'd Merc t-stats are 140F. Many gauges with their inaccuracies will show 120-140F.

BBCLiberator

iTrader: (2)

Every marine engine I have ever had put off more steam from the starboard side. It's been discussed enough times times that I quite worrying about it, too, even though years back it had me pretty concerend. You should be good.

donzi matt

iTrader: (1)

What drive is on this? I have noticed every boat I have owned with through hull exhaust and an alpha drive with the water pump in the drive has done this. The bravo pump must move substantially more water because it is much less pronounced. I had an 87 Donzi which started as an alpha boat with a big block that was the worst offender but after converting to a bravo drive I never noticed the issue again and the water volume out of the starboard pipe was much improved.

AWOL

Best I could do from what I have on my phone:



Heres the plugs. This orientation would be as if youre looking forward on the boat (left side is port, and in order)



EDIT: Its a BRAVO 1 drive

EDIT 2: I also replaced the plugs since I pulled them with new ones. New wires are ordered as well

Blueabyss

1. I think your temp gauge is off. 2 I think the side that is cold is your problem side and I think it is due to the wrong gasket between manifold and riser. It probably needs a restrictor type gasket. That would let less water through it and probably force a little more water through the other side. Some motors just do that. I prefer the thermostat housing with the check balls and 160 degree thermostat. With that setup mine runs 170 on the gauge regardless if Gulf water temp is 60 or 95. I would try pulling off the cold side riser for inspection and conformation of Gasket type. Take pics. Dont try and trust your memory. It will be stuck on pretty good, You will probably have to hit it with a dead blow sand hammer a few times but not too hard. VERY IMPORTANT DRAIN MANIFOLD FROM BOTTOM PLUG BEFORE REMOVING RISER. 3 Report back with pics. What is the water temp you are running in? 4 Get some NGK plugs. I can look up number or someone else can give part # if you like . Also look to see if it has a thermostat. There is a plastic cup that needs to be in the correct orientation in most merc thermostats. Take pics of that too. I guess it might also be possible you threw an ear off the impeller and it made its way to the riser and is also holding thermostat open but thats beyond my knowledge level.. Someone else should comment on that .

Chris

AWOL

Went down to the slip today and played around with the hoses and thermostat again. I didn't realize where the check balls were when I tried the first time. I ended up looking online and saw which hoses try were in, they looked fine but we're missing the springs. I ended up removing them entirely and no more uneven flow or excess steam. Temps stayed under 150 even after some WOT blasts.

Everything is good and I appreciate all the tips.