running hot at idle

I have a 1988 Ski Nautique 2001 I have removed the thermostats and changed the impeller. When driving boat around temp is normal about 160-170 but as soon as I come off plane the temp shoots up to over 190+. My question is could the water pump behind the main pulley be going bad or could there be another cause?

you might have an air leak somewhere between the point where your boat picks up water from the lake and your raw water pump. Have you checked all of your hose clamps? use a socket to tighten them.

yep that'll do it

Yup, or Nautiqueparts or I'd think N3 as well.

I think Dim Quotes high on shipping. But then, if it's something they can stuff into a regular envelope they'll lower it at the time the card is charged. Might be worth doing the transaction over the phone just in case, but Karen had told me that about the envelope.

Got O rings here and regular mail works. The part is like 7 bucks or so it won't be that much to ship.

Hey phatsat looking here locally but if I can't find one I'll certainly order one or two may do it any way

Those o-rings are important. My onboard kit includes an extra strainer o-ring, engine v-belts, the original prop, prop puller kit including nut and key, tools obviously, a tube of permatex ultra black, some wire and assorted crimp connectors and strip/crimp tool, voltmeter, elec tape, duck tape. Need to add an extra rwp impeller (probably the most important thing).

We usually have our pontoon boat on the lake, too, and it carries a ton of tools and parts, and a ton of beverages. :)

We make sure someone onboard has a spare ignition key, too. I spent a half hour one day hotwiring our pontoon boat at a public launch, because my key was hanging in the kitchen. I got a lot of weird looks.

I taught my teenage son to check the strainer regularly, and showed him how easy it was to dump the o-ring overboard. Then I told him if he does that, he pays for the new one! I'd better tell him he pays the shipping, too, lol.

I've also taught my kids to be ANAL about watching the temp gauge. Taught them the general aviation panel scan thing, and told them there's no reason they can't do a quick scan every 20 seconds or so. It gets ingrained and soon it feels wrong not to scan, kind of like wearing a shoulder harness in a plane or car. I also taught the kids how not watching the temp gauge can destroy the engine... and again who will be paying for it. With fun comes responsibility...

marmon77 wrote: Hey Glass seeker, you say I have to run a thermostat. Can you explain why please? Thanks

I'll jump in with Andy's comment. The T stat is needed to maintain the normal operating temp of the engine. If you are running without one, the engine will not perform like it should. Fix the problem on the suction side of the RWP. Don't "back yard".

A thermostat is a must on a boat.

make sure you get the right thermostat...marine not automotive...get the right temp!

It's normal for the temperature to creep up when you shut the motor off.

But, it shouldn't creep up when idling. Mine goes up just a little coming off plane when the motors been running at higher RPMs, then goes down again at idle.

Also, I believe you want the 143* t-stat for your carbureted engine.

10-4. Thanks again guys will get it changed out to the 143*
Also I would leave the boat running while changing riders that's when it would creep up.

marmon77 wrote: 10-4. Thanks again guys will get it changed out to the 143* Also I would leave the boat running while changing riders that's when it would creep up.

If you're leaving it running and you're seeing that big of a swing and temp, there is most likely a suction side air leak somewhere.

Double check your strainer for tightness and the presence of your O-Ring gasket.

Also check the strainer to make sure it's not gunked up (I have to check/clean mine often where I run in weedy water), the same for the incoming side of your tranny cooler.

Double check all of your hose clamps for tightness. Also make sure the hose ends aren't degrading.

Also, make sure the tranny cooler didn't get squished at some point from over tightening of a hose clamp.

If all that checks out, the RWP itself may need attention.

whats wrong with the 160* on a carb motor? I did that for my supra and its fine. Was thinking about doing the same for my CC..