Raw water pump failure and smoke...

[scenarioL113]

I went for a quick cruise with my son the other day and as soon as I went up on plane I started to smell something burning. I looked down off the bridge and did not see anything and assumed that the smelll was from the Meadowbrook Pkwy (near Jones Beach, NY) that I was next to (thinking it was a car fire)...
I cruised for another 10 seconds and the smell was a bit more pronounced and now when I looked aft I was trailing white smoke. I IMMEDIATELY slammed the throttles down to figure out what the hell was going on.
I was not far out and turned around immediately to head towards the dock and my alarms started going off. My temp on starboard was well over 200 and I shut her down. I had my son steer while I pulled the hatch cover to see what was goin on in the engine room and I saw nothing. I assumed I toasted a fan belt but it turned out to be the raw water pump.

I inspected the exhaust hoses and the fiberglass piping. I noticed the hose off the wet elbow was delaminated to some point and replaced it. I am assuming thats what was burning. I ran water thru the sytem at the dock and dont see any leaks so far so will keep my fingers crossed.

I never had that happen so before. I have ran hot from sucking a plastic bag or something but never like this and SO FAST. I was not up on plane for more than 30 seconds.

I tore down the sherwood pump and found the woodruff key was disintegrated for the most part and the bearing closest to the impeller was wiped out.

I ordered a brand new pump and also a major overhaul kit (with a new shaft) to rebuild the old one for a spare...

We were close to going on fire I guess... geez!

I will keep my fingers crossed that I did not damage the head....Cummins dont like to get too hot

[Tony Meola]

Frank

When was the last time you replaced the impellar?

With no water running thru them, they heat up pretty fast.

[Snipe]

Frank I have two spare pumps if yours don’t come! I bought two smx pumps.

[scenarioL113]

Thanks Jason, Hopefully it will be in by Tuesday. (if not I will take a ride into NJ LOL)

The Impeller was new LAST season Tony. The impeller is in excellent condition but one cog tore when the key let go so it is shot now. I think the "seal" let go and raw water got into that 1st bearing.

The major rebuild kit will be now for the spare pump. Basically every part will be new except the gear and the housing.

I removed the exhaust hose yesterday and the hose at the elbow def started separated (from being cooked). I believe that was what was smoking. I replaced and ran water through the system and do not see any leaks as of yet but that was only by running the dock hose thru the system.

[Carl]

With no water to cool the exhaust the hose from the dump cooks...ask me how I know.

Ok, glad you did...well my last boat had a new 318 installed, new "upgraded" risers before I bought. I trailered it across the Island to my dads friend's marina who let me stay on the cheap and was a couple of block from our shop at the time. It needed lots of cleaning, glasswork, paint transom, boot stripe, rail work, etc etc. On the cheap became he would not take a dime from me... especially as I cleaned up the yard around my boat as I worked on it...so he got a ton of his favorite kind of beer...cold.

Wow, what a long intro - So after a couple of weeks I finish, boat goes in for a sea trial, all is good and decide to take around the Island to my marina by myself. I say as It was a good 20 miles of waters I'm not sure of...busy commercial, Tugs, Ships Ferries, bridges blah blah blah...About 12 miles in boats running well, I'm getting comfortable and I'm getting into the waters I know so I goose the cruise up a bit, the exhaust sounds a bit different...I'm thinking its because I'm going faster. Than an odd burning odor and now loud exhaust and I see smoke from hatch. I bring motor down, pull hatch and it's loud, smoke and water gushing out from the dumps hose. Panic, I'm on fire, I'm sinking! what to do, call for help...then comes to wait, breathe. waters coming out of the hose over the waterline and just from the motor, engines cool, I have oil pressure, smoke is now just exhaust...and hole in hose explains the sound...original burn was the hose that did burn...but not on fire and ok now. I shut motor, water stops coming in, cut an old piece of hose, put some hose clamps together and patched the hole. Started her up and continued at a slow at slow cruise. I ran a bit, slowed, felt hose, if good a bit faster, felt hose and ran on the edge n backed off some.

What it came down to was the New Upgraded risers had spray bars to disperse the raw water over the exhaust...they had very little clearance and clogged easily. I tried to buy the old style, but dealer told me to save my money and drill them out...that was the end of that problem.

So to answer the question you didn't ask...a lack of water burns up those exhaust hoes pretty quickly and Yup, they smell like burnt rubber and will scare the hell outta ya for a bit.

[Tony Meola]

Frank

Surprised the key let go so fast. That bearing must have frozen up and when you started her everything let loose.

Carl

Years ago we had a pump failure. Had the big blocks in her at the time. To keep her from running in circles, we connected the wash down pump to the system and was able to run the engine at about 900 RPM's so we could idle home slowly.

Once those impellars let go, the water will flow pass the impeller.

[Carl]

That was smart thinking, Tony. I recall dad in the bilge of a friend's boat when the circulating pump belt broke. They tried to jury rig something but didn't work...final straw was to spin the pulley by hand. Not great, but able to keep a fast idle pace making it back to dock under power.

Necessity is the mother of invention