Anybody grenade a new impellor?

Two weeks ago I grenaded my existing impeller (didn't change it last year so, I deserved the on the water repair), pulled out my new spare which was probably a couple years old but, new in package. Put it in and went my merry way. Two weeks later, put the boat in the water and got a days use out of the new impeller, then on the third day on the new impeller, just after launching and waiting to pick up, the new impeller grenades. I pull out the raw water pump to find that there weren't any pieces larger than my pinky nail.

Has anybody grenaded a new impeller?

I can only attribute the 2nd failure to an aged impeller.

Chris
Get the Grip you Deserve
www.wakejunky.com

Impellers need to be changed out as the rubber breaks down over time, life can be extended by storing in sealed packaging, thats why new ones are delivered in vacuum packed or sealed bags. Also lube the impeller when you install it (veggie oil or vaseline) as they can break down due to over-heating i.e. the first time you start the boat after changing the impeller it runs dry until the water gets sucked in! I quite often run a hose up and fill the water pipes up again before starting the engine (easier if it has a flush kit installed).

Also double check that your sea strainer isn't blocked

Is it a plastic housing ? If so did you change that as well ?

I think it's attributed to an aged impeller, the "new" impeller was not shrink wrapped but, in a plastic display package. So, I'm guessing that it just dried up over time but, don't understand how I got two days of use on it before it grenaded.

Chris
Get the Grip you Deserve
www.wakejunky.com

I was asking about the housing because the plastic housings often have to be changed as well after a impeller failure because they get damaged as well. A damaged housing might cause premature failure.

Rubber breaks down over time. Yes, substantially slower if shrinkwrapped or vacuum sealed, but it still breaks down over time.

remember when I had to borrow your spare from your old boat to fix mine in my old boat after burning up my spare on the old steve and maria houseboat?

My strainer was leaking just enough to burn up the impeller. I think I went through 4 impellers in two weekends before I finally figured it out. It was weird because it would work as long as the boat was moving, it was the sitting idle that was burning them up.

Check your hoses and strainer for leaks.

I blew up a brand new impeller over Memorial Day. Wasn't on the water more that 5 minutes. We got on the water late as I was having sound quality issues. Put the boat in the water about 12:00. Picked up a buddy who parked the truck and motored out of the no wake zone. Hammered down on it. Got on a plane and started to check gauges. Temp gauge was a about 250. Shut it down as the screamer started screaming. Saw black smoke pouring out the hatch. Opened the hatch and had everyone grab vests and more to the bow. Tons of smoke was pouring out of the engine compartment. I thought there was a fire. My on board fire extinguisher was not going off however. Once I made sure there were not any flames, the beer started flowing as it was way to hot to even get close. After about 30 minutes, I took the hoses off the sea strainer to see if there was any debris in it, but it was clean. I pulled the fuel /water filter bracket off and the raw water pump off.
(after a buddy in another boat brought me the only socket I didn't have to get the last bolt) Opened the pump up and the impeller was destroyed. I had just installed it 2 weeks earlier. I always carry an extra and now the needed socket as well.

Once I got the boat back together, it cooled down. I did, however, notice that I was leaking water now from all around the exhaust manifolds and the risers. Also from around the thru hull exhaust hose. The leaking water was able to run down the block and a plug wire. That then caused the plug wire to arc on the block losing a cylinder (makes it very hard to get on a plane trying to pull a rider. also water would squirt on the belt and cause it to slip. We did limp around the lake for the next 3 days and had a crazy good time anyways.

Towed the boat back to my work, 4 hour drive. Pulled the risers and manifolds off. Found that the casting plugs were plastic. When it got that hot they melted and allowed the water out instead of going through the exhaust and cooling it down. Also melted some wire loom that was in the area, but not touching. Had to replace all the 4" exhaust hoses as they were melted badly. It got really effing hot in there. I replaced all the gaskets to the manifolds and risers. Took it back out this past weekend and ran like a champ. Great to have all 8 cylinders working again.

Fiasco for sure!!

you sir are lucky you did not pop a head gasket or two. If you blistered the hoses and melted loom it was hot enough to do it.

I was really worried about it. Luckily the heads were still getting enough water flowing thru them. However, the manifolds were spewing all the water out so the were hotter than sh$t!

These stories only make me more nervous with my new impellor as well as the new spare. Wish there was a way to know if the spare is goodenoigh to go in.

Chris
www.wakejunky.com