Port Engine problem on 10.8 Meter International

[TrojanInternational91]

Hi all....I was out today taking a short cruise in my 10.8 meter Trojan International and it started out fine. I took it out of the river and onto the lake and wanted to get it up on plane and clean the engines out a little because they seemed to be running a little ruff from winterization. Anyways when I got the boat going around 15-20mph I looked down at the temperature gauge on the port engine and it was very high. Almost pegged. I slowed her down and killed the port engine and went back in on single screw. At a higher speed there was no water coming out of the port side from the engine, but there is when I am going slow. Someone told me it might be an impeller problem. I am not that good with the engine aspects of the boat, but I would love to know some things that I might be able to check before I have to resort to an expensive mechanic. If it was a bad impeller, where are these located on a 10.8 meter international and how easy (or hard) are they to replace. Any suggestions would be GREATLY appreciated.

Thanks in advance!

(by the way I have twin 454's Mercury Crusaders, gas, v-drive)

[RWS]

There should be a strainer between the seacock and he impeller. Check that first.

THe impellers are rubber and pliable when new. As thy get older they become brittle and less flexible and they become "set" in a pattern. (like us!)

The impellers should be replaced every second or third season. You'll find them inside the raw water pump, just upstream of the strainers.

Replace the one on your genny as well.

Are you sure you have V drives on that 10.8?

All the 10.8's I've seen were straight inboards

If your engines are blue, they are Crusaders, black are Mercurys.

Most of the International series were fitted with Crusaders from the factory.

The 10.8 is a wonderful vessel with a great deal of usable space and a very practical layout.

Let us know how you make out.

RWS

[rossjo]

If you have water low at lo speed, but none at high, then its either an impeller or your port scupper is partially covered (under the boat -- when was your bottom last cleaned?). Can't hurt to check the strainer, but that would not stop flow at high speed when its flowing at low ....

[yorklyn]

Replace the impellers! On my boat its easier to take off the pump assemply to work on it. I think its 2 bolts and a fan belt. If you are missing any of the vanes off the impellers (the rubber fins) you need to find them as they can create blockages in the heat exchanger. Its really easy to do. The heat exchanger is the cylinder where the antifreeze goes (I'm assuming your fresh water cooled) They have plates on either side of the cylinder with a single bolt holding them on. Simpley take off plates (purchase new rubber gaskets at the local marine store, their cheap) and pick out any rubber or crud, you should be able to see through the cooling tubes so check for blockage. If there is any buildup a radiator shop can cook them out for you. the whole process is really fairly quick and easy to do. Be carful not to overtighten the bolts that hold the plates on as you only need enough pressure to seat the rubber gaskets.
When I first bought my boat the bearings in the water pumps were also shot. I bought a rebuild kit but then found out The entire waterpump assembly with impeller wasn't that much more so I purchased 2 new pumps and change the impellers every other year.

Good luck