Prostreeter

Four weeks ago I had a problem with water in the oil.New head gaskets,valve job and IMCO Powerflow exhaust installed.All that's fine now.Problem is water just trickles out the starboard side exhaust pipe and port side has very good water flow.Just got the boat back from the shop yesterday and went out to the lake today.Got out of the no wake zone, got on plane and within 4 minutes temp guage went to 200.

I dont know the exact termonology but the rubber hose that surrounds the pipes which is clamped tight with hose clamps melted.Now if I just idel the boat around the temp is 160.Once I throttle up and get some rpm's going the engine temp goes up.

I've only had this boat out twice with a total of 30 minutes ofrun time and problems each time.The engine is a 1999 502 mpi.

Can you guys please help me.Why is water just trickling out the starboard side.What should I be looking for.Thanks guys.

ENFORCER24

does the thermostat housing have the T on top that sends water to the riser? , if so theres a rod with 2 balls on it that keeps exhaust back pressure out of the cooling system , problem is that if theres any problem at all with the rod and balls it will send all the water to one side and you'll have one riser running very very hot , i'm not sure how the imco powerflow is plumbed but it sounds like an issue i had a few years go
just my .02

Donzi38ZXXX

Sounds like it could be the sea water pump or the impeller. If it is the sea water pump - be sure to flush the oil cooler after replacing. Good Luck & Get used to it - Its a BOAT.

Sorry - thought you were talking twin engines - my bad.

Griff

My Imco's were plumbed the exact same way as the stock merc manifolds/risers. One hose to each manifold and one to each riser. The manifold transfers water to the riser just like the merc manifold via an interal water passage between them.
I never had any issues.
I second checking the ball/rod assembly in the housing.

Prostreeter

After closer inspection of the sea water pump running on the garden hose,the housing is cracked and I can see a steady spray of water coming out of it.Could this possibly cause one exhaust to be much hotter and poor water flow from one exhaust?

Vinny P

Either way, that pump needs to be replaced. Start with that and see what happens. Just for your information, you should be servicing that pump before the start of every season.

nocigarette

Yes it can.........does the boat have a water pressuer gauge, if not put one in.......When you put the new housing on be sure to put a new impeller and inspect the old one, if there are any parts of rubber of the old impeller missing trace the water hose to the next cooler and take it loose and look for rubber debries..........



If you had half the problems i have had with a boat you would think this problem is no worse than having to check your oil.....

Puck it

jeff1000man

AMEN

Prostreeter

Thanks everyone.You boys on OSO really know your chit.Thanks.Oh,and I love this boat.I'm not getting rid of it,I'm getting used to it.

Prostreeter

Well the shop installed a new impeller and housing which it needed.The shop also checked the oil cooler and power steering cooler and found no blockage or debris.I questioned the shop about the ball and rod assembly and he said this particular engine does not have it.

Went out to the lake today and same thing happened.Got on plane and temp went to 200.Shut the engine off for a couple minutes and started it up and the temp guage went all over the place.The rubber bellows on starboard exhaust melted again too.I'm so ready to give up.What else could be causing the heat issue and poor water flow out the exhaust?

Please,I really need some help.