I ran my 496ho (Nordic Rage) on the trailer with the earmuffs yesterday. Water was coming out of the front of the bullet at the bottom of the outdrive, none out of the exhaust. The water temperature gauge never got over the 120s, but a continuous alarm came on after running about 2 minutes.

I immediately shut off the boat and there was a small amount of smoke / burning rubber smell coming from the port exhaust. After searching this forum it appears I might not have had enough water pressure, and I should have taped off the lower water pickup.

Should water come out of the corner exhaust when running off the hose? How do I know if the heat damaged / melted the impeller?? How do I know if the water is flowing through properly off the hose?

I would really appreciate some insight... this boat is a way different setup than my previous boat and I am still trying to figure it out.

Chances are if you smell rubber you may have burned the impellor, they are rather simple to remove, I would check it.

They make a rubber cone to cover the lower holes vice using tape, you can get them from Merc.
Bryan

Aquaman41

I have a Nordic Rage also, but not with the corner exhaust. I forgot to tape the front of the bullet once also. I got the exhaust hose pretty hot in a couple of minutes. Figured out what was wrong and taped the bullet and got much better flow though the exhausts. I didn't burn anything through and I've not had any problems since. I also had a bad impeller once after a winter layup. Didn't smell anything but I sure heard it. I would think that if you could smell it from your exhaust it would be a hot hose. Of course, if you're impeller is fried the belt running on the water pump pulley would heat up also and you could smell that in the engine compartment.

Pat

Earmuffs absolutely suck. They are not efficient, nor reliable, and if they fall off, split, or fail while in use, you are screwed. All it takes is a few seconds of running dry and your impeller is done. Your water temp gauge may have never GOTTEN any water to take a reading from. Your impeller definitely needs replaced; fortunately your SWP housing is brass, and should be OK. Its not a hard job. I have pulled my off twice while bobbing in the ocean.

Its definitely preferred to have a T-fitting in your raw water pump hose before your SWP, and attach your hose at this point. There are several threads on this topic.

Change your impeller at the beginning of every season regardless of hours, and/or every 100 hours.

Well, thanks for the responses.

It must have got pretty hot pretty fast - the impeller was torn up, missing 4 blades. Found em all, replaced the impeller and I am running fine.

My mechanic had seen this before and rigged a pretty cool device for me that put a splitter from the hose. One side goes to the ear muffs, and the other side goes to kinda like a outdrive mask that feeds water to the lower water pickup. The bottom portion is held onto the outdrive with surgical tubing. Anyways it gets water to all of the inputs and stays in place really well.