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View Full Version : Overheating issues on a 95 prostar


jdredfield
06-02-2008, 11:58 AM
I have a 95 prostar 205 with about 300 hours on it and I have never had a problem with it. I ran it in a river last week and could've picked up some trash but as I run it for a while at speed the temperature slowly rises until it gets close to 220 or 230 degrees and then the engine will shut down. I have tried to flush it and I've looked at the impeller and I'm putting in a new 143 degree thermostat. Where else should I look for trash? What is the canister that is inline on the water pickup hose? It has a couple of oil looking lines coming off of it. Should I pull that? The original invoice lists the engine at 275 TBI 1:1. I am assuming I have a plain jane chevy 350. Is that correct?

etduc
06-02-2008, 12:27 PM
I have a 95 prostar 205 with about 300 hours on it and I have never had a problem with it. I ran it in a river last week and could've picked up some trash but as I run it for a while at speed the temperature slowly rises until it gets close to 220 or 230 degrees and then the engine will shut down. I have tried to flush it and I've looked at the impeller and I'm putting in a new 143 degree thermostat. Where else should I look for trash? What is the canister that is inline on the water pickup hose? It has a couple of oil looking lines coming off of it. Should I pull that? The original invoice lists the engine at 275 TBI 1:1. I am assuming I have a plain jane chevy 350. Is that correct?

I have a '94 Prostar 205. The canister, your talking about, is the transmission cooler. There is an intake screen, on it, that can get clogged. I preferr to remove the hose, between raw water intake and the cooler, to visibily inspect cooler. ( and hose.) Also, inspect hose after pump, for debris.

143 stat or 160 stat. Some say 160 stat, is better for performance and economy. Be sure to use a marine grade stat.

454Prostar190
06-02-2008, 12:28 PM
The "canister" is your transmission cooler that runs in line with your raw water pickup for your engine. You have probably picked up debris and the line from the pickup beneath the boat to the water pump is blocked. I had the same problem and tried impeller, thermostat, another impeller etc. and learned what I now know right here. I flushed the raw water hose, trans cooler and she ran cool again! Rick

damaged442
06-02-2008, 12:33 PM
That happened to my buddy this weekend with his 94 Maristar 225 VRS. It was running hot, and he never checked the intake screen. I took the intake line off it, it was packed with pine needles. After cleaning it out, the temp stayed at 140. Hopefully, it's that simple for you also. Good luck.

BIGBADBLUE
06-02-2008, 12:36 PM
Very easy to clean ... just follow the raw water line up from the bottom of the boat and you will fine it. My '94 205 has a strainer and all you do is remove the hose and clean out the strainer.

bigmac
06-02-2008, 12:37 PM
Did you actually pull the impeller out and look at it, or just take the cover off and look at it in the pump? If the latter, you may very well have missed significant damage to it.

The effort necessary to "check the impeller" is about 90% of the effort to change it for a brand new one (plus $30, of course). I would first pull the lower hose off the transmission oil cooler and check the strainer for debris, then I'd change the impeller.

JimN
06-02-2008, 12:59 PM
These boats use a 160 degree thermostat, not a 143 degree. The only one that uses 143 is the LT-1, and that's only one of them. The main one for the cooling system is 160. A 143 degree 'stat will waste gas and a cold engine isn't as efficient as a warm one.

BrianM
06-02-2008, 02:28 PM
These boats use a 160 degree thermostat, not a 143 degree. The only one that uses 143 is the LT-1, and that's only one of them. The main one for the cooling system is 160. A 143 degree 'stat will waste gas and a cold engine isn't as efficient as a warm one.

Jim I am sorry but this is wrong. I talked to Indmar specifically about this when I changed my t-stat. The one that was in it when it came from Indmar was a 143. That is confirmed by what was in mine and what I replaced it with, Although the t-stat is a 143 the boat operates in the 160 degree range. I ran a 160 tstat in mine for a short time and it would allow the boat to run in the 180 range which is a bit hot.

chico
06-02-2008, 06:22 PM
I`m with Jim,indmar told me to use a 160 also.Mine works fine.

jdredfield
06-03-2008, 01:26 PM
Thanks for all the replies. I pulled the water intake hose at small canister and found about 3 inches of debris on the screen which I probably picked up in the river I was skiing on. I am suprised the boat ran at all. Anyway, thanks for the help.

mikeg205
05-13-2012, 11:14 PM
I`m with Jim,indmar told me to use a 160 also.Mine works fine.

Bumpin' for us fairly and new used MC owners... Funny the Mastercraft Manual and the Indmar Manuals are different.

After reading hundreds of posts - it's almost like an oil thread :D....

JimN
05-13-2012, 11:34 PM
Bumpin' for us fairly and new used MC owners... Funny the Mastercraft Manual and the Indmar Manuals are different.

After reading hundreds of posts - it's almost like an oil thread :D....

In cold water, a 143 degree t-stat will cause the engine to be very inefficient, running rich. In warmer water, as long as the oil cooler isn't clogged and is checked regularly (which is mentioned in the manual), a 160 degree t-stat will be just fine. Running at 180 isn't a problem and will never trigger an overheat. It will, however, keep the engine from running rich and wasting gas. In extremely hot air and warm water, the t-stat will basically run a bit open a lot of the time if the recirculated water makes it necessary.

On an LT-1, the 143 degree t-stat is like a pre-heater for the raw water and keeps the engine from experiencing a bad thermal shock when cold water hits the hot metal.

Also, we were told to use 160 degree t-stats when we went to MC training- the manual is for original specs and won't usually be changed unless something major calls for it. In most cases, the service bulletins cover any changes that are necessary and aftermarket manual printers don't always get these.

mikeg205
05-13-2012, 11:41 PM
What about the non-after market engine manual from Indmar? it calls out 160 - JimN I am sure this comes around and around...

I wonder why they thru 143's into them from factory...products....manufacturing...things change..good to know people are willing to share good info....

JimN
05-13-2012, 11:58 PM
What about the non-after market engine manual from Indmar? it calls out 160 - JimN I am sure this comes around and around...

I wonder why they thru 143's into them from factory...products....manufacturing...things change..good to know people are willing to share good info....

Hard to say 18 years after the fact.

mikeg205
05-14-2012, 12:24 AM
good point...