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Safe to run boat without thermostat?


wakeboarder3780

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I bought a new to me 23 LSV late in the season. On the trip back my transmission in the tow vehicle had issues. It has been getting fixed since. In the meantime I winterized the boat by removing the thermostat and running antifreeze through the engine.

Now the tow vehicle is fixed. I plan on riding to see what the boat is like. The water is very cold by now (38 degrees I'm guessing). Would it be "OK to leave the thermostat out but give the boat an extra long time to warm up? Would it take obscenely long to warm up without the tstat in?

I'm just trying to save myself some work. I can put it back and then take it back out right after but I'd rather not if I don't have to.

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My guess would be that with a steady supply of 38 degree water, an no thermostat, the boat would never warm up. If you can't get it above a certain temp (120 degrees, I think) your engine will not allow you to go over a certain RPM...you'll never get it out of the phased warm up cycle.

I could be wrong.

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You can be kicked off here for asking questions like this. Put your thermostat back in.

:cry:

I'll put it back in. I didn't think it would be a problem.

Edit: would anyone care to discuss more about why this is a problem? I'm assuming the post above from RTS has it correct but I wouldn't mind someone else chiming in as to why it's such a no-no. Just trying to learn!

Edited by wakeboarder3780
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Boat won't heat up to 160 without a thermostat in 70 degree water. I'd put the thermostat back in and leave it there, just put antifreeze in the boat after you drain down but when the boat is still warm.

-Chris

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Didn't know it was necessary to get the boat up to op temp. Just figured it helped expedite the process. Good to know, thanks for the info all.

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Didn't know it was necessary to get the boat up to op temp. Just figured it helped expedite the process. Good to know, thanks for the info all.

I think if you were just idling around, all would be ok. Years ago, we did that in a jet boat and ran a few minutes at lot's of throttle.

Threw a freeze plug and almost flooded the boat ! What I think happened was, the extremely cold water adjacent to the extremely hot cylinder walls warped the block enough to allow the freeze plug to pop out.

Engine was okay after shutting off and putting freeze plug back in, but what a shock to an engine.

I am thinking of doing this though, lol, when our lake water get's above 85 degrees. Even when open, I think a thermostat slightly constricts water flow ?

Steve B.

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A cold motor does not burn fuel efficiently. I learned this in a costly manner. My ex dodge V-10 had a bad thermostat for quite awhile causing it to run cool. It eventually plugged up the Cat with carbon deposits (unburned fuel). A$2,000.00 cat only used in this vehicle for a limited time by Dodge and scarce as chicken teeth.

Replace the thermostat.

Edited by LS-One
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:cry:

I'll put it back in. I didn't think it would be a problem.

Edit: would anyone care to discuss more about why this is a problem? I'm assuming the post above from RTS has it correct but I wouldn't mind someone else chiming in as to why it's such a no-no. Just trying to learn!

The thermostat regulates waterflow through the engine. Without it, impeller would be pumping unrestricted cold water through the engine at quite a volume. I agree, you'd never get warm, but more importantly, you'd have no control over the volume of cold water being pushed through a hot engine if it ever did get hot which is not good. Ever sprayed a car engine with a garden hose? what happned? ok now imagine that on the INSIDE of your engine.

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My uncle has an old Nautique and live in Orlando. In the summer he runs it without the Thermostat. Has done this for years, I guess those old Nautiques run hot and a easy fix is running without the T-stat...

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My engine will only run 130 to 140 degrees in 38* water with the t-stat. I quessing that ice cold water constantly pouring over the exhaust manafold keeps the heads well below operating temperature.

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The thermostat regulates waterflow through the engine. Without it, impeller would be pumping unrestricted cold water through the engine at quite a volume. I agree, you'd never get warm, but more importantly, you'd have no control over the volume of cold water being pushed through a hot engine if it ever did get hot which is not good. Ever sprayed a car engine with a garden hose? what happned? ok now imagine that on the INSIDE of your engine.

a long with this idea, I have heard that removing the t-stat can cause localized overheating aka hot spots. The idea is the water is flowing through at such a velocity that it forms air pockets in the tight corners. Then that section of the head/ block can overheat.

never confirmed it...just heard about it. Kinda makes sense though.

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My guess would be that with a steady supply of 38 degree water, an no thermostat, the boat would never warm up. If you can't get it above a certain temp (120 degrees, I think) your engine will not allow you to go over a certain RPM...you'll never get it out of the phased warm up cycle.

I could be wrong.

:plus1:

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Isn't the purpose of creating an operating temperature to help vaporize fuel for combustion? With that theory, a cold engine does not burn fuel well, therefore affects performance (short term) and creates deposits (long term).

That's a guess by me, but I'm pretty sure that is correct.

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Cold engines run rich to account for the extremely high frictional losses at start up, vaporization isn't so much of the problem.

Bearing clearances are too tight at low temps, oil is more viscous at lower temps, piston/liner gaps change at different rates.

That said the warmer an engine goes the more efficient it is, that's why most cars run closer to 200°F versus what our boats run at.

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Ran my boat all summer with out a thermostat, about 40 hours or so. Didn't know I didn't have one until I went to winterize it this fall. I purchased it last fall, never ran it, but never thought to look for a thermostat when looking at purchasing it.

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The thermostat regulates waterflow through the engine. Without it, impeller would be pumping unrestricted cold water through the engine at quite a volume. I agree, you'd never get warm, but more importantly, you'd have no control over the volume of cold water being pushed through a hot engine if it ever did get hot which is not good. Ever sprayed a car engine with a garden hose? what happned? ok now imagine that on the INSIDE of your engine.

:plus1: You can get very uneven cooling in the engine as the volume and speed the water passing through the engine is sometimes to fast to cool well.

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No worries guys, I put the t-stat back in (it was actually very easy now that the housing had been split and was easily movable. I didn't even remove the hoses from the housing, just the 3 bolts tipped them apart and slipped it in.

I rode last night here in Wausau, WI. It was 39 degree air temp and lightly raining / 38 degree water temp. With the dry suit / neoprene booties / closed toe bindings / ski gloves / neoprene face mask it, it wasn't too bad. It was totally worth it to see the wake with the new wedge I installed (way more peaky than without a wedge!).

Well anyhoo here's a shot on the swim deck after riding. I happen to have a mustache for "Movember" right now so the pic is extra stylin.

http://img33.imageshack.us/i/wakestachesmall.jpg/

Thanks for all the advice!

PS had a big scare for a second when emptying ballasts. The ballasts completely stopped working on the center and rear left tank. I had about 6 hours before it was going to hit freezing temperatures so I was really starting to get nervous (new boat, didn't know a whole lot about it yet). Turns out it was the little breaker switches underneathe the panel where the cd player is (down by the cup holder, look up and you'll see it). I was excited that I wasn't going to have to replace fuses, or jimmy rig jumper cables to my ballast pumps ;)

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I believe he meant restriction.

:oops: Yep-er!! A long day yesterday. I have been in the north woods for a week and a half and just trying to catch up with home work and E-Mail.

And I can't spell anyway. :blush:

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