88Maxim

I recently purchased and 88 22' Stingray maxim wtih a 330hp 454. I knew the boat had been kept in salt water prior to my ownership, but i was unsure of how long. Anyay, i took the boat out and the engine got really hot, so i shut it down, let it cool.Meanwhile I decided to remove the thermostat, which seemed to be stuck closed. After cooling, the boat started up and ran pretty well. After getting home, I replaced the stat and noticed alot of corrosion in the housing, so i decided to remove the risers also, just to be safe. Needless to say they were trashed, completely clogged with rust, etc..... So i purchased a new emi thunder system and installed it. Upon startup of the boat today, the starboard side exhaust was pumping out hot water almost instantly, while the port was still cool. So i shut it off and plugged up all the outlets/ hoses, except for the block drains. The port side shoots water out of the drain quite well while the starboard side is a bit slower. After pumping water through it for a while it seemed to get better but not great. I then restarted the boat and there was a noticable difference in water temp this time but not as bad. Niether side is scolding hot. You can hold your hand on the starbord side for about 10 seconds before it gets too hot, where as port side you can hold for about 20.I also back flushed all the hoses and i recently rebuilt the raw water pump.

Beyond removing the heads and investigating further, what else can i do? Is this heat difference normal? Would running a crossover help water flow? Id rather not replace the engine as i just purchased the boat. Sorry for the long post. Any help is appreciated.
Ed

Audiofn

Were you running it on a hose or in the lake? Mine used to do the same thing on the hose. Lots of water out one exhaust and none or very little out the other. You sure the water pump is ok?

88Maxim

This was done on the hose, after the exhaust was replaced, havent had it back out in the water yet. Guess the hose could be part of it, never really thought about that. I know the raw water pump was just rebuilt. I cant vouch for the other one though. The PO said it was recently replaced and it does appear that it was.....

MOBILEMERCMAN

Run the boat and finish your inspection on the water. You cannot completely troubleshoot a overheating problem on a hose. One side may be warmer than the other but you should be able to hold your hand on them both. Seldom does a hose test deliver enough water to keep the exhaust cool for long.

88Maxim

Thanks I will give that a try. Hoping to get out this week.
Ed

88Maxim

Took the boat out this weekend. The one riser was still cooler too the touch. The boat idled in a no wake zone at about 160 degrees. After taking off and cruising at 35-40 it creeped up to about 180 and would rise higher if I went any faster. After cruising at 35mph for about 20 minutes i slowed down and and the the alarm went off and the temp shot way up. Docked the boat for about 35 minutes and took off, temp shot back up to 180-190, slowed back down to to talk to someone and the alarm went off again...temp went way up again. Idled for a few minutes and all of the sudden the temp just dropped down to 150 in an instant. I know i have blockage someplace. This did the same thing when the stat was bad, and now the stat is new. Im thinking the block is clogged up in the water jackets, as ive changed the stat, flushed all the hoses looked inside the oil cooler, changed the raw water pump impellor and flushed water through the heads while the exhaust manifolds were off. Also, water flows freely in and out of the outdrive. Guess im gonna pull the heads and take a closer look... Any suggestions are appreciated. Btw....my dad was following me in his boat and said the exhaust would take turns spitting water.

ENFORCER24

the ball valve at the top of the thermostat housing , its known for causing crazy problems , its 2 balls on a rod that regulates water to the risers , and stops exhaust back pressure in the cooling system , i would replace that with new , before pulling heads off , or ....... and this was just me , i pulled it out completely and tossed it , but that was just me and i dont want to be the reason that someone blows there stuff up , but it fixed an eratic temp problem for me

88Maxim

I had already removed the ball valves prior to the previous post. So that doesnt seem to be the problem.
I recently flushed the starbord side block somemore and got the drain to flow a bit better.
I took the boat out again last night and removed the stat. The boat ran great while cruising only got to about 160. However during long wide open throttle blasts it would creep up to 190 and continue to rise slowly until i backed off a bit. Its still not right, as this thing should be super cool with no stat....Right?
Trying to avoid tearing this motor down. Might pop the freeze plugs and see what i can see........

BY U BOY

If you are running 160* with no T-stat ther is a problem somewhere that needs to be found.Have you run into any mud or sand lately?

ENFORCER24

I agree with By U BOY , i run no stat in my motor and even running it hard i only get to about 120 , theres a water flow problem no doubt , maybe the circ pump is failing? if the impellor in that id leaning to one side it could cause better flow on one side of the block , just brain storming here , i hate to see someone loose prime boating weeks.