Day from hell

Hi everyone, hopefully everyone had a better weekend then i did. Need a few ideas on things. I popped my 05 Moomba LSV in Saturday, and it did the usual smoking and carring on after beening winterized but seemed to run ok.
After about 10 minutes on the lake i noticed at idle and slow speeds the temp climbed to pretty much maxed out around 200 degrees, then when i got up to speed it would go right back down to normal. So we tried to pull someone and the same sinario happened although this time it was around 200 degrees and would not even take off to get up on plane. Did i hurt the motor? Bad impeller? bad thermostat?

200 you should be alright need to change thermostat and impeller at the same time there both inexpensive parts and easy to do. Dealers recommend doing them at the same time.

Cool i will have them do both. What temp do they start melting down at? Just a little nervious that it wouldn't even get up on plane. Didn't know if that was a censor or something restricting it from hitting high rpms.

In the Indmar instruction manual for our boat is says something about a temperature sensor that will not let the boat go over a certain RPM when over a certain temperature. I can't remember what temperature that is but that sounds like what happened.

I had the samething happen to me this weekend, on my Super Air and all it was was the strainer filter for the water coming to the impeller pump was loose. I didn't get it tight. Check to make sure the o-ring is there and that it's tight and not leaking.If it starts sucking air in it will over heat.

Your impeller is fried. Thermostat is probably OK. I had the same thing at the end of last year. When your running fast the pressure from the scoop is forcing water into the engine and cooling it down, but when you slow down the pump doesn't pull any. Just replace the impeller. Don't forget to clean your coolant lines, the transmission screen, and you might want to pop the top on the thermostat anyway to check for pieces of the old impeller in there.

Another bumper for the impeller. Nearly everytime I heard someone describe what you did, that's what it has been.

funny. i was just about to dig up an older post (about 2 weeks ago) about a similar situation for me. except mine happened twice then cleared up. took the boat out for a somewhat short notice trip this weekend and didn't even get out of the marina before i was up to about 220 deg.
so i was checking back to see how and where to look for any pieces of impeller in the cooling system. thanks...

BTW, my local supra dealer sells impellers for $35 w/gasket and o-ring. i'll definately be changing them yearly from now on...

every 100 hours is a good rule of thumb for an impellar.. so easy and inexpenzive might as well change the thermostat at that time too..

That poor guy you were pulling must have been freezing given the weather that day!!! And I did get up for a split second Let me know if you need me to take it anywhere or do anything with it while your on your honeymoon next week mang!!!

Thanks guys, you are all a big help!!

Brando i think that is about the most you got out of the water. You weren't the only one cold if you recall me doing a graceful trip over the v-drive comparment into the lake fully clothed like 10 minutes before that pic. Hey at least your new bun got a kick outta it!!

A loose hose clamp can cause the same thing to happen with the temp.

Here's what my impeller looked like when I pulled it out this spring (sorry, bad camera phone pics). It held the shape of the cavity, was cracked, and looked very old and worn when it really was not. Take them out every off-season if you plan on re-using them the next season. Better yet, just spend the $30 and replace at the beginning of every season.

I had mine in for 2 seasons and actually looked new when I took it out.

without a doubt it is a bad impeller

mine has 380 hours on it and is not quite two years old. Season never ends in Az. Plan on changing it before I go to powel at the end of june. Last time I looked it still looked new with no cracks. Better not push my luck much longer.I do carry a spare in the boat.