View Full Version : super high temp in no wake zone

01-17-2009, 08:31 PM
Anyone know of a write-up on changing out the impeller on an 2001 X9? And also for checking the strainer?

I highly doubt there was something blocking the intake, this happened in a very clean lake, there was not much debris. I checked after pulling the boat out of the water, looked clean to me.

Temp was creeping up on 240 by the time I noticed. So I shutdown and let her cool, then limped back to the dock :-(

Think anything else could have been damaged from getting that hot momentarily?
Thanks in advance...

01-17-2009, 08:58 PM
There is a ton of information here on Team Talk about impellers and strainers, but I think the best info is in the owner's manuals. I'd recommend downloading the 2004-or-later owner's manuals (http://www.mastercraft.com/knowledge/owners_manuals/) and looking at those procedures. 2005 (http://www.mastercraft.com/files/manuals/2005_MasterCraft_Owners_Manual.pdf) or 2006 (http://www.mastercraft.com/files/manuals/2006OwnersManual.pdf) have the best pictures, IMHO.

It would also likely be helpful to download the Indmar owner's manual (http://indmar.com/ProductLine/index.html).

01-17-2009, 09:10 PM
Your impeller may be damaged. Fine when up at speed, but not pumping enough water at idle speeds. Check your impeller.

01-17-2009, 09:44 PM
i agee. make sure you pull the impeller out of the hosing and inspect it. the back side of the impeller may be damaged. looks fine in place......but tore up on the inside

01-17-2009, 11:10 PM
Which motor?

01-18-2009, 12:16 AM
Thanks for the suggestions everyone...
It's the Predator 310HP

Anything damaged by getting close to 240??

We'll pull the impeller and check it out...

01-18-2009, 12:17 AM
Only has 120 hours!!

01-18-2009, 08:27 AM
Damage? It's possible. Gaskets and rubber exhaust parts don't like those temperatures and if the cooling system got no water at all, the 240 degrees you saw was only at the temperature sensor. The oil and filter absolutely have to be changed, too. High temperature breaks the oil down and it loses its ability to lubricate as well as it should.

FYI- if it overheats, shutting it down for a few minutes and "limping home" doesn't do much good. Cars have a radiator and unless that ir a hose ruptures, the motor will still have coolant in it to keep the motor's temperature more consistent. If a raw water pickup clogs or the impeller dies, the motor gets nothing and can overheat very unevenly, causing a lot of stresses. Unless you're in real danger, shut it down, open the motor box and replace the impeller or find the cause of the overheat before starting it again. Cold water going into an already overheated motor can crack the castings. When you buy the impeller, get two and don't just buy it without the gasket.

01-18-2009, 09:29 AM
First thing to do if when the engine overheats, or runs at higher-than-normal temps is pull the lower hose off the transmission cooler. There's a strainer there. If you find weeds, clear 'em. If you find rubber pieces or if the transmission cooler strainer is clear, you need to pull your impeller because it's likely toast. If you're going to pull the impeller to check it, you might as well replace it (for $30). To change, remove the 4 brass bolts holding the cover on, pull the impeller straight off its splined shaft. Toss it and the gasket. Put some NevRseeze or grease on the shaft and slide the new one on, matching the folding of the vanes to the rotation..helps to lube it up with some dish soap, glycerine, food grade silicone grease. Yes, the inside of the pump housing is eccentric...flat on the hose side. Be careful bolting the cover back on, the bolts are soft (brass).

Second thing to do after an engine overheat is paddle the boat back home, or get it towed. I think it's a BIG mistake to try to limp home on an engine with a non-functional cooling system.

01-18-2009, 11:32 AM
Once to job of changing the impeller has been mastered, it all the more reason to carry a spare new impeller and the proper tools on board to change right there in the middle of the lake. It's normally no more than a 15 minute job on a direct drive.

01-18-2009, 04:13 PM
Could be multiple problems... I had the water intake hose going to the impeller literally fall off. I also know on a lot of the newer mastercrafts they had a batch of defective water coolant hoses. Mine sprang a leak on a Sunday and ended a wonderfull 100 degree day of boating.

01-27-2009, 10:30 PM
Thanks for all the great advice everyone! I'll be buying two impellers ASAP. And as soon as I have a nice weekend I'll get out there and replace it, and check/clear the strainer. I'm also gonna check/replace the thermostat because as I had the engine cover open cooling down there was some boiling action in the larger hoses, and when I'd squeeze them it felt like the water had no where to go! I don't know why they were so full of water, seems to me that if things were that hot then the thermostat should have been able to get wide open...

Engine and tranny oils will be changed ASAP!

Thanks again! Hopefully there's nothing major wrong. I'll keep ya posted :(

east tx skier
01-27-2009, 10:43 PM
To parrot something Jim told me once, shine a flashlight up your tail pipes and look for blistering. An easily spotted indicator.

jdl xstar
01-28-2009, 01:44 PM
Do most inboard engines use the same type impeller? What kind does an MCX use? Sounds like I might as well get a spare.

01-28-2009, 04:00 PM
Snug up your hose clamps with a 5/16" nut driver next time you warm up the engine too.

01-28-2009, 04:07 PM
Do most inboard engines use the same type impeller? What kind does an MCX use? Sounds like I might as well get a spare.

Great question, I'm having a hard time finding some place that carries parts for these things. I need a thermostat and a couple impellers...

01-28-2009, 04:11 PM

Buy two and keep one in the glovebox. I also keep spare impellers for my ballast tank pumps as well.

07-01-2009, 03:22 AM
Those engines are pretty tough..If you didn't run it for a long time at that high of a temperature you should be fine...But get an extra impeller and gasket and keep it on the boat...