Go Back   TeamTalk > Maintenance Tips, How-tos and Refurbishing Topics > Engine / Drive Train

Reply
 
Thread Tools Display Modes
  #1  
Old 02-22-2011, 11:44 AM
mrprostar's Avatar
mrprostar mrprostar is offline
TT Enthusiast
 
Join Date: Aug 2007
Boat: 1996 Prostar 205
Location: Abq
Posts: 457
Whats this wire do?

I have 96 205 with the 5.7 TBI. My temperature reading was getting very high so began doing some looking around. I replaced the thermostat in the intake manifold (160 degree), no change. I tried to find a replacement for the one in the triangle block but couldn't find one the correct size. So I left it out completely and the temperature stayed lower but when running at any rpm above idle the temperature shoots way up with 190 then plummets very quickly to 120 then gradually goes back to 190 and repeats. I replaced the thermostat in the intake manifold again thinking it was sticking and then finally opening at 190, but it didn't change. I began looking around again and found a wire on top of the thermostat housing that was broken at the connector. I havent been able to find the same connector for a replacement, but was wondering what this wire does and could it have something to do with my problem? I understand that the thermostat I removed it supposed to keep the water in the system warmer so 50 degree water doesnt enter the block, explaining why it the temp drops so fast and so low. But why isn't it opening at 160? Before it would fluctuate from 140 to 165 and never any hotter.

So to stop rambling and get to the point:
What does the wire do?
What is the part number (skidim) for the thermostat in the triangle block?
Where can I find another connector that has the screw into the thermostat housing and then a screw on wire connector on the other side?

Thanks in advance.
__________________

1996 Prostar 205
Reply With Quote
  #2  
Old 02-22-2011, 11:54 AM
JLeuck64's Avatar
JLeuck64 JLeuck64 is offline
MC Fanatic
 
Join Date: Jun 2005
Boat: 98 Prostar 190 Stars & Stripes, LT1
Location: Oregon
Posts: 695
You should check the trans cooler for blockage/obstructions. If plugged from debris that gets sucked out of the water will reduce the volume of coolant flow through your engine.

Oh, and pics of your wire could help the second question...
__________________
http://www.mastercraft.com/photopost...er=2572&sort=1
Need LT-1 parts?
OIL FILTER: Factory installed is a Penzoil P23, Afta market brands, AC Delco PF-454 and a Fram PH-13 or PH-30 will work.
SPARK PLUGS: AC Delco MR43LTS (gapped to .040")
FUEL FILTERS: AC Delco 25171391 (pump inlet side)
89058397 (pump outlet side)
IGNITION WIRES: Call Inboard Online @ (877) 327-7175 and order part numbers 556010A (odd bank) and 556010B (even bank)
Reply With Quote
  #3  
Old 02-22-2011, 12:24 PM
Barefooter92's Avatar
Barefooter92 Barefooter92 is offline
MC Fanatic
 
Join Date: Jun 2008
Boat: 1997 Prostar 205; 1996 Sea-doo GTX
Location: Defiance Ohio; Big Long Lake Indiana
Posts: 705
Same problem this past summer same boat. Check your trans cooler. This will eliminate 50% of your problem and posts from TT members. This should only take you 2 min to check and clean. Part of my rutine maintenance now.
Reply With Quote
  #4  
Old 02-22-2011, 12:35 PM
JimN's Avatar
JimN JimN is offline
MC Master Poster
 
Join Date: Jul 2004
Posts: 11,512
Quote:
Originally Posted by mrprostar View Post
I have 96 205 with the 5.7 TBI. My temperature reading was getting very high so began doing some looking around. I replaced the thermostat in the intake manifold (160 degree), no change. I tried to find a replacement for the one in the triangle block but couldn't find one the correct size. So I left it out completely and the temperature stayed lower but when running at any rpm above idle the temperature shoots way up with 190 then plummets very quickly to 120 then gradually goes back to 190 and repeats. I replaced the thermostat in the intake manifold again thinking it was sticking and then finally opening at 190, but it didn't change. I began looking around again and found a wire on top of the thermostat housing that was broken at the connector. I havent been able to find the same connector for a replacement, but was wondering what this wire does and could it have something to do with my problem? I understand that the thermostat I removed it supposed to keep the water in the system warmer so 50 degree water doesnt enter the block, explaining why it the temp drops so fast and so low. But why isn't it opening at 160? Before it would fluctuate from 140 to 165 and never any hotter.

So to stop rambling and get to the point:
What does the wire do?
What is the part number (skidim) for the thermostat in the triangle block?
Where can I find another connector that has the screw into the thermostat housing and then a screw on wire connector on the other side?

Thanks in advance.
Wire color and photos- post both.

These have two temperature senders- one for the gauge and one that reports to the ECM (one yellow one and black wire). If the one with the broken wire has only one wire, that's the one for the gauge and it should go to full cold if you disconnect it. If you short it to ground, it should go to full hot.
Reply With Quote
  #5  
Old 02-22-2011, 06:27 PM
André's Avatar
André André is offline
MC Maniac
 
Join Date: Jul 2004
Boat: Prostar 190 1994
Location: Near Sherbrooke,Québec,Canada
Posts: 4,410
Doesn't the 5.7 TBI have only one thermostat?
__________________
Keep skiing!!!
Reply With Quote
  #6  
Old 02-22-2011, 06:52 PM
Double D's Avatar
Double D Double D is offline
MC Maniac
 
Join Date: Sep 2004
Boat: 1994 Mastercraft, ProStar 205, 350 Indmar with 275 hp
Location: Massillon, Ohio
Posts: 4,193
This wire?? I think its to the red light on the dash. To hot = red light.

I could be wrong...
Attached Images
 
__________________
If its not a competition ski boat, its always second best.

1994 MasterCraft ProStar 205
275 HP 350 Chevy Indmar
Monster Tower & PerfectPass

Check out the MasterCraft Buckeye Bash on Facebook!

"In my many years I have come to a conclusion that one useless man is a shame, two is a law firm and three or more is a congress." - John Adams
Reply With Quote
  #7  
Old 02-22-2011, 07:36 PM
ahhudgins's Avatar
ahhudgins ahhudgins is offline
MC Devotee
 
Join Date: Jun 2009
Boat: 79 S&S, 87 Prostar Powerslot, 95 Maristar 200VRS
Location: Virginia
Posts: 1,732
Send a message via Yahoo to ahhudgins
Quote:
Originally Posted by Double D View Post
This wire?? I think its to the red light on the dash. To hot = red light.

I could be wrong...
Same set up as my 95 TBI. Mine is put away for another month, but the two sensors on top of the manifold are for the temperature gauge and the over temperature light you mentioned. One has a brown wire, the other has a brown wire with blue trace (I think). My sensor for the ECM (as JimN mentioned) is on the side of the block below the spark plugs. It has two wires: Black and yellow. My 95 only has one T-stat.
Reply With Quote
  #8  
Old 02-22-2011, 08:20 PM
ahhudgins's Avatar
ahhudgins ahhudgins is offline
MC Devotee
 
Join Date: Jun 2009
Boat: 79 S&S, 87 Prostar Powerslot, 95 Maristar 200VRS
Location: Virginia
Posts: 1,732
Send a message via Yahoo to ahhudgins
Someone can correct me if I’m wrong, but I still had this old picture from when I was trying to explain to a friend how the thermostat works. I don’t know if my 95 has another t-stat below this one, don’t know why it would need one?

Lake water leaves the impeller and enters the triangle housing through the large hose in the bottom left (marked with pink arrow) and goes through the housing to the other large hose for the engine water pump which pushes water into the block. Water is also directed up through the small hole to supply water to the exhaust manifolds. Water is HELD in the block until it heats up enough to open the t-stat. T-stat opens up and directs water up (noted by blue line) to the top of the housing and out the exhaust manifolds. An infrared temperature sensor can be purchased for less than $100 to check your actual engine temperature to see if it’s over heating or you have a gauge/wire problem.

My 95 uses a 142 degree t-stat that I got at NAPA. Any local auto parts store will have them.
Attached Images
 
Reply With Quote
  #9  
Old 02-23-2011, 10:26 AM
mrprostar's Avatar
mrprostar mrprostar is offline
TT Enthusiast
 
Join Date: Aug 2007
Boat: 1996 Prostar 205
Location: Abq
Posts: 457
Double D- yes that is the wire. Thank you, I'm sure thats what it is for. I will have to double check, but I don't believe there is a sender on mine like that. I cant find a picture of the connector and the boat is at my parents house. I'll try to get a picture this weekend. But the connector is a little screw without a head on it and it screws into the housing on one end and then the connector is screwed on it with the wired crimped on the other side.

ahhudgins - Also a good picture of the wire on the right side of the picture. Definitely the tan wire. Your explanation is the same as my understanding. The second thermostat I was referring too was in the hole where the blue arrow is and the other one is in the intake manifold, like in the picture.

So what does it do? It looks like it keeps water from entering the exhaust manifolds until its hot?
Attached Images
 
__________________

1996 Prostar 205

Last edited by mrprostar; 02-23-2011 at 10:37 AM.
Reply With Quote
  #10  
Old 02-23-2011, 10:32 AM
JimN's Avatar
JimN JimN is offline
MC Master Poster
 
Join Date: Jul 2004
Posts: 11,512
Quote:
Originally Posted by mrprostar View Post
Double D- yes that is the wire. Thank you, I'm sure thats what it is for.

ahhudgins - Also a good picture of the wire on the right side of the picture. Your explanation is the same as my understanding. The second thermostat I was referring too was in the hole where the blue arrow is and the other one is in the intake manifold, like in the picture.

So what does it do? It looks like it keeps water from entering the exhaust manifolds until its hot?
It works as a T adapter- to allow cater to go to the engine and it also provides a constant supply of water to the exhaust manifolds.
Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off


All times are GMT -4. The time now is 10:17 AM.