sydneyACE
06-06-2012, 02:21 PM
Hey everyone!
Details - '84 Supra Rider with Chevy 400 small-block and Sherwood belt-driven raw water pump.
(*Disclaimer* I made-it out to the lake on Friday afternoon with my new gear and a little-bit of ballast as-well, so the season hasn't been a totall failure yet. No need to feel too sorry for me.)
So on Sunday I got some people together, gassed-up the boat, and made-it to the lake.
I was pretty excited! I had 5 80# sand-bags under the ski-locker for ballast, my new board, and new rope.
I also bought 4 6-gallon water jugs to provide a little extra weight. I even convinced my brother to bring as many 5-gallon buckets with lids that he could find. (Ended-up with 4 of those.)
Long-story-short, I motored accross the lake to the far-end without problems. When we got down there, I proceded to fill-up all my water jugs and buckets. We trolled-around a little so my pops could do some fishing. After a while, he gave-up and I was ready to board. I decided to do a quick oil-level check before gearing-up and riding. When I opened the cover it seemed a little hot in there. I felt the manifolds and they were way too hot. I checked my (transparent) hoses and they were dry.
The first thing I thought was maybe something plugged up the pick-up on the bottom of the boat. (It had stormed the day before so there was some junk in the water.) I disconnected the hose from the trans heat-exchanger and blew into-it (in the direction of the pick-up) to see if I could dislodge any debris that might be clogging it. Air blew through freely and it didn't feel like anything came-out. I hooked everything back up and cranked the engine to see if it would suck in any water. No luck, the damage had been done. I took-apart the raw water pump, and sure enough, the impeller was shredded. Sadly for me, my cheap-ass was too broke to buy a spare last season and my day was over. :(
TLDR:
I ordered-up a new impeller (and a spare), but I'm really concerned about WHY the impeller shredded.
Any ideas as to WHY my impeller got toasted?
It didn't look like it got too hot (no signs of melting/heat-cracking, etc).
My theories are that something plugged-up the pick-up for long enough that the impeller ran dry and eventually came-apart.
I thought maybe it sucked something in there that physically damaged the impeller, but after thinking about-it, I find that unlikely. The slats in the pick-up aren't that big, PLUS it would have to go through the trans heat-exchanger which has even smaller holes (look to be about 3/16 or so).
So, if anyone can provide some insight as to WHY this thing went-out, I would love to know. If there's anything I can do to help prevent this from happening again, I need to do it. At $40 a pop, I don't want to chew-up any more of these things.
As a point of reference, a co-worker of mine has a 2007 Moomba that he's been running on the same Impeller since new. I know I'm not the luckiest guy in the world, but what gives? How can he get 4+ years out of an impeller but I barely got 1?
Details - '84 Supra Rider with Chevy 400 small-block and Sherwood belt-driven raw water pump.
(*Disclaimer* I made-it out to the lake on Friday afternoon with my new gear and a little-bit of ballast as-well, so the season hasn't been a totall failure yet. No need to feel too sorry for me.)
So on Sunday I got some people together, gassed-up the boat, and made-it to the lake.
I was pretty excited! I had 5 80# sand-bags under the ski-locker for ballast, my new board, and new rope.
I also bought 4 6-gallon water jugs to provide a little extra weight. I even convinced my brother to bring as many 5-gallon buckets with lids that he could find. (Ended-up with 4 of those.)
Long-story-short, I motored accross the lake to the far-end without problems. When we got down there, I proceded to fill-up all my water jugs and buckets. We trolled-around a little so my pops could do some fishing. After a while, he gave-up and I was ready to board. I decided to do a quick oil-level check before gearing-up and riding. When I opened the cover it seemed a little hot in there. I felt the manifolds and they were way too hot. I checked my (transparent) hoses and they were dry.
The first thing I thought was maybe something plugged up the pick-up on the bottom of the boat. (It had stormed the day before so there was some junk in the water.) I disconnected the hose from the trans heat-exchanger and blew into-it (in the direction of the pick-up) to see if I could dislodge any debris that might be clogging it. Air blew through freely and it didn't feel like anything came-out. I hooked everything back up and cranked the engine to see if it would suck in any water. No luck, the damage had been done. I took-apart the raw water pump, and sure enough, the impeller was shredded. Sadly for me, my cheap-ass was too broke to buy a spare last season and my day was over. :(
TLDR:
I ordered-up a new impeller (and a spare), but I'm really concerned about WHY the impeller shredded.
Any ideas as to WHY my impeller got toasted?
It didn't look like it got too hot (no signs of melting/heat-cracking, etc).
My theories are that something plugged-up the pick-up for long enough that the impeller ran dry and eventually came-apart.
I thought maybe it sucked something in there that physically damaged the impeller, but after thinking about-it, I find that unlikely. The slats in the pick-up aren't that big, PLUS it would have to go through the trans heat-exchanger which has even smaller holes (look to be about 3/16 or so).
So, if anyone can provide some insight as to WHY this thing went-out, I would love to know. If there's anything I can do to help prevent this from happening again, I need to do it. At $40 a pop, I don't want to chew-up any more of these things.
As a point of reference, a co-worker of mine has a 2007 Moomba that he's been running on the same Impeller since new. I know I'm not the luckiest guy in the world, but what gives? How can he get 4+ years out of an impeller but I barely got 1?