'97 TBI Thermostat and Engine Temp

[BrianM]

Hoping to get an answer from JimN or Engine Nut here:

When I was trouble shooting my temp gague I took a look at the thermostat to see if it was sticking or looking funky. The thermostat was not the issue but since it was a little corroded and I needed a new housing gasket I order new ones from SkiDIM. Didn't look at what temp it was when I had it open so asked DIM and they reccomended the 160. They said the engine is designed to run in the 160 - 180 degree range for optimum combustion etc. Well after getting the gauge issue sorted out I went back to replace the t-stat and found that the old one is a 143. So the question is which one do I run? I put the new one in (160) and skied with it and all was fine with temp reading 160-170 on the gauge. Is the 160 going to be to warm this summer with 90 degree air and water temperatures? Should I put the old one back in? New to the EFI thing and want to make sure that I am doing the right thing here. Don't want to fry anything but also want the boat to run at optimum temp.

I used to run a 143 in my '88 because it would run to hot (180- 190) with the 160 in it.

[Kevin 89MC]

I'll first admit I'm no expert, but my first reaction is the 160 is correct. The 143 would be too cold for proper combustion. Out of curiosity, what was the normal operating temp on your '88 with the 143? I just put a new stat (160) in my '89 last fall, and I thought it ran about 170.
Good luck.

[AirJunky]

The 143 came in my 94 TBI stock from the factory. But Heatercraft recommended I bump it up to the 160 when I installed the heater. So I guess it depends on if you have a heater or not.

[BrianM]

I'll first admit I'm no expert, but my first reaction is the 160 is correct. The 143 would be too cold for proper combustion. Out of curiosity, what was the normal operating temp on your '88 with the 143? I just put a new stat (160) in my '89 last fall, and I thought it ran about 170.
Good luck.

The '88 ran about 160 -170 with the 143 thermostat in it. When I first got the boat I installed a 160 and it would run 180-190 and after it would sit a bit after a high speed run it would heat soak to about 200. As soon as I started it up the temp would go right down but it was just a little hot for my blood. Granted the higher temp could have been an inaccurate near 20 year old gauge though.

[jimmer2880]

Not an official answer, but I run a 143 in mid-summer, and 160 early & late season for the heater. Since I don't need a gasket for my T-stat - I'm lucky enough that it's just a 3-bolt & 1 hose clamp swap.

[André]

160 in my 94 TBI

[planoboy]

Check out the earlier thread. My 94 350 TBI ran pretty much the same, 160 as 143, awesome. I think engine smelled hotter. (not saying it had anything to do w/ it, but my ECM had to be "recalibrated" shortly after bumping up the Thermo) I went back to OEM 143 when I r/r ECM. my advise, run what the mfg designed. (143).
http://www.tmcowners.com/teamtalk/showthread.php?p=51749#post51749

[BrianM]

Just bumping this to the top again. Trying to get JimN or Engine Nut to chime in.

[east tx skier]

Brian, this will serve primarily as a BUMP. But I recall reading of several instances where people, on skidims recommendation, have gone with the 160 tstat with good results.

Check your PM.

[BrianM]

OK so after getting no consensus from here I decided to go directly to the source for my answer. Gave Indmar a call and talked to one of their techs Jim. Nice guy and very willing to help. Gave hime the engine serial number so he could look up build specs. He told me the 160 the one to use. So for the record TBI 350 uses the 160 thermostat as per Indmar.