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jstwkd
05-21-2002, 08:39 AM
Allright guys I need some help!took the boat out last wknd.When I am coming out of no wake zone and straight up wood it the pump or motor revs to 6000 rpms I let out and get back in it takes off like a bat out hell.Why is the pump cavitating (Im geussing)I also ended up with a knock this weekend but thats another problem motor is coming out tonight!

Hallett19
05-21-2002, 11:17 AM
my best guess, you might have had some shit stuck in the pump, happened to me once, but I had to dislodge it myself. If there is anything, i.e. sticks, weeds, anything, it will cause cavitation, or maybe you just have way too much damn horsepower!!!

jstwkd
05-21-2002, 12:23 PM
I finally got a hold of my pump guy.He said this is normal and that if i go to a bronze lipped wear ring it would be better.HP I dont think so Im only pushing around 600. and this is according to a desk top dyno so who nows?

77charger
05-21-2002, 03:24 PM
I get the same thing with a new impeller and wear ring if i stab the throttle it will cavitate.But if i use 3/4 throttle it will move out good.My motor makes good power and was never a prblem wit ha stock motor.My pump is being blueprinted and the impeller detailed so this will hopefully help out.Will know this weekend.

AGGRESSOR JETS
05-24-2002, 08:33 AM
Barring something in the pump- You are not loading- 6000 rpm's says HP- is this new or did it load before. Also knocking can be the pump also. Dave- Normal is to Load and leave

79Hawaiian
05-25-2002, 12:03 AM
Any pump will cause cavitation if it looses it's prime. If you are pumping lots of water out the pump you need lots of water coming into the pump. If my intake catches air it often will cavitate until I back off. Mine cavitates often when my foot is in it and hit any big rollers that cause the boat to catch air. Then again mine sits pretty shallow. I have just learned to use the foot throttle to power the boat over waves to prevent the cavatation in the first place.

Jungle Boy
05-25-2002, 04:20 AM
If you have mechanical packing, check it. It may need a bit of an adjustment.

jim lee
05-25-2002, 08:48 AM
Sorry, this is kinda' SPAM-ish.. but.
If you have enough HP to cavitate your pump off the line, even though its set up correctly, this is what the Launch Controller was developed for. It allows you to program how fast your RPM ramps up from the start.
http://www.banderlog.com/launchController/images/littleLC.jpg
The link http://www.banderlog.com/launchController/launchController.html
Again, sorry to spam, but on this thread I just couldn't help myself.
-jim lee