1994 Prostar 205 LT1 overheating.

[Rbrower190]

I have a 94 Prostar 205 with the LT1 that prior to this year would overheat the first time after coming off the trailer into the lake or after coming off the boat lift after being out of the water for a day or more. What I would do that got it to stop was to put it into reverse and then I would watch the temperature gauge go back to normal. Now it seems to be happening almost every time I take it off the lift. Putting it forward and then reverse at idle speeds doesn't always work right away like it used to. Since this all began I have been very conscious of letting it idle to warm up to see what the temperature gauge does the first time running it each day. Any ideas? Thanks for any help! Ross

[mikeg205]

Have you done the lt1 cooling modification?

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[bret]

Have you checked the trans cooler to see if it's got any blockage?
When was the last time the impellor was changed?
When was the last time BOTH thermostats were changed?

As Mike mentioned, has the cooling update been done on the engine?

https://teamtalk.mastercraft.com/showthread.php?t=31626

Other good info here too
https://teamtalk.mastercraft.com/sho...d.php?t=105169

[Rbrower190]

Mike and Bret,

Thanks for your response. It has had the LT1 cooling setup done. I have a sea strainer so would I need to check the transmission cooler for blockage? If so, where exactly is that? The last time I replaced the impeller was 2 years ago. It has about 20 hours on it. I know that might not fly on here

[Rbrower190]

I have not changed the thermostats. Is it something a hack like me could do?

[88 PS190]

so, where exactly is that? The last time I replaced the impeller was 2 years ago. It has about 20 hours on it. I know that might not fly on here

I'm not an impeller purist, I leave mine in over winter and only replace when needed. One of mine went 6 years and looked new when I took it out.

I am convinced that what kills them is being started dry, followed by sediment. So before starting in the spring just make sure to pour water down the pipe to the impeller so it doesn't start dry and have to suck up enough water to prime.

[MIskiboat]

Yea. Change the thermostats for sure if impeller is new.
A few bolts. Pay attention to orientation when you remove them so you don’t put in backwards. Just take a pic w phone.
Make sure to get the right ones.

[bret]

I'm not an impeller purist, I leave mine in over winter and only replace when needed. One of mine went 6 years and looked new when I took it out.

.

With the reverse cooling of the LT1, if pieces of the impellor break free, they lodge in the cooling ports of the head. I was just asking when his was last changed.

[d2jp]

I know the LT-1 is a different animal and doesn't play well with high temps. But I would verify your gauge reading with an IR to see what ballpark engine temps really are.

'92 351w here, running 160 thermostat.....I started to get high temp readings (180-190) after long slalom runs at 34mph coming back to idle after skier drop. Checked trans cooler, impeller, back flushed where possible, checked and drained mainfolds..all of the usually suspects for a blockage and nothing. However, a quick shift to neutral and reving engine will bring it back down to 160. Then...on early morning sets with nav lights running I noticed the temps were up even higher...adding the blower would then increase temp readings even further. So grabbed my IR thermometer and shot temp readings from all over the engine. Heads front to back, block, oil pan, etc. No engine temp read over 165, although gauge read 195 with blower and lights on. For piece of mind, I've repeated this check numerous times (while my ski buddies roll their eyes, LOL).
Bottom line - on my boat the temp gauge is wired via a daisy chain of now 30 year old wires and connectors, the increased resistance from aging wire+connections is exaggerating the readings. Add in additional draw from lights and blower and it's even worse. It's on my winter upgrade list.
If you've checked all the usual LT-1 fixes, I would verify your gauge reading - it could be exaggerated by wiring or faulty sending unit.

[Mystic3D]

when you added the strainer, is the water intake hose higher than the transmission cooler due to how it needed to be routed? I have seen if it's 2' plus off the bottom, it's harder for the impeller to pull prime..

[mikeg205]

I'm not an impeller purist, I leave mine in over winter and only replace when needed. One of mine went 6 years and looked new when I took it out.

I am convinced that what kills them is being started dry, followed by sediment. So before starting in the spring just make sure to pour water down the pipe to the impeller so it doesn't start dry and have to suck up enough water to prime.

I am watching you now 88.. how dare you go more than a season on an impeller.. [emoji41][emoji13]

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[88 PS190]

hhaha well someones gotta say it.

[waterlogged882]

hhaha well someones gotta say it.

I run several seasons on the same impeller.

.

[mikeg205]

I run several seasons on the same impeller.



.

I dont believe u water[emoji13][emoji1787]

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[waterlogged882]

I dont believe u water[emoji13][emoji1787]

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lol... I promise it is true. It's a little out of character for me but I am finishing a third season as I winterize this year...on the same impeller.

I'll swap it out next year as I change my oil in the spring. The direct drive is really easy to change (both).

I owe you a Coke.

.