Taking on water? bad Cavitation

[Brew Master]

Hey guys, with your help I was able to fix my rev limiter problem, now I took the boat out for the first time and and seemed to be a little sluggish out of the hole but to be expected with a single 800 motor. But the problem got worse as the day went on. Every time we stopped for a while it seemed to be taking on water, as in a inch or so by where your feet are. I opened up the engine compartment and there was water in there up to about the starter, maybe 3 or 4" . I noticed as the day went on it took longer and longer to get up on plane, to where it finally would not, im assuming because of all the extra water weight. The motor is turning 7k rpm. The bilge pump is working(at least I hear it) but not positive it is actually pumping.

So basically it ran great motor wise and at first would get up on plate relatively quick considering the motor size, but after every time we shut it off and stopped for a little while, then tried to go again it would take longer and longer to get up on plane to the point where it was full throttle for several minutes but would still not plane out. Any help is greatly appreciated. thanks Mike

 

[Dr Honda]

ok... you have 2 problems.

1) The water in the passenger compartment is from a bad Scupper valve. If you look under your swim deck... you will see a valve on the starboard side. (Driver's side) I'm guessing the rubber flap is hard, and warped... or there is stuff caught in it. Regardless... it's less than $10, and it probably needs replaced.

2) I'm guessing the carbon seal, and it's associated parts are just warn out. I would buy a new boot, carbon ring, O-rings, and C-clip... and rebuild the seal. in proper working order... you should be able to mash the throttle, and the boat should just go. Also... I am going to assume that's where your bilge water is coming in at. BUT.... since you say you have 3" or 4"... you could have a leak somewhere else too.

 

[Brew Master]

ok... you have 2 problems.

1) The water in the passenger compartment is from a bad Scupper valve. If you look under your swim deck... you will see a valve on the starboard side. (Driver's side) I'm guessing the rubber flap is hard, and warped... or there is stuff caught in it. Regardless... it's less than $10, and it probably needs replaced.

2) I'm guessing the carbon seal, and it's associated parts are just warn out. I would buy a new boot, carbon ring, O-rings, and C-clip... and rebuild the seal. in proper working order... you should be able to mash the throttle, and the boat should just go. Also... I am going to assume that's where your bilge water is coming in at. BUT.... since you say you have 3" or 4"... you could have a leak somewhere else too.

Great info and thanks for the response! I will check that scupper valve and just buy the new flap just to be safe. The thru hull fitting was first guess as well.
I took a look at the engine compartment when we were underway and I could not see any water coming in but there was definitely way more water in there than there should have been

 

[Brew Master]

Do you know a good place to get the valve and carbon seal from? looks like there $33 for the valve and $41 for the carbon ring from partspitstop.com Thanks Mike

 

[Dr Honda]

The carbon ring: ether from our sponsor, or the place you listed. (both are good)

The Scupper: Check ebay Item number: 160715173367. $6 delivered (it's a universal part. Don't need to pay seadoo for it)

 

[Brew Master]

awesome, ill buy the carbon seal from the sponsor for helping to make this site possible. Thank you sir

 

[Brew Master]

update, so I replaced the scupper valve, replaced the carbon seal and bellow, and completely rebuilt the pump with all new bearings and wear ring and a nujet impeller. Found a couple other problems while I was at it like why the reverse would not work. Now all I have to do is go take her for a test ride again.

 

[Dr Honda]

Sounds like you are ready to go.

Let us know what happens at the water.

 

[Brew Master]

Well took her out and she ran good for the most part. The boat still takes a while to get up on plane with 5 people in it but that's to be expected with all that weight. I have a bad rectifier so I ordered up one of those too. Good new is everything I replaced worked great and we had fun all day on the boat.

 

[Brew Master]

took the boat out again today and had a few friends with us, so there were 4 adults and a kid on the boat and it would never get up on plane, I am positive we were over the 650lb weight limit by several hundred pounds. So I am assuming that I just this boat weighed down to much? With 2 or 3 people on it it gets up on plane no problem. Also I am running very lean, I checked the spark plugs and they were completely dry and crusted over brown. Anyone have the factory specs for the highs on a 96 challenger? Thanks Mike

 

[Dr Honda]

Dry and tan is about right... but post a pic of the plugs. As far as the high needles... on a 96 challenger... they are closed.

If you are over weight... that's not a good thing... but that boat should still get out of the water. Try this.... on the carbon seal boot... put a couple big zip ties around it. (down in the valleys of the boot) This will help keep the boot from getting sucked back under hard acceleration. Also... did you notice if your driveshaft had more than one spot for the stainless ring clip? If it did... push the ring back, to hold the seal tighter.

 

[Brew Master]

Dry and tan is about right... but post a pic of the plugs. As far as the high needles... on a 96 challenger... they are closed.

If you are over weight... that's not a good thing... but that boat should still get out of the water. Try this.... on the carbon seal boot... put a couple big zip ties around it. (down in the valleys of the boot) This will help keep the boot from getting sucked back under hard acceleration. Also... did you notice if your driveshaft had more than one spot for the stainless ring clip? If it did... push the ring back, to hold the seal tighter.

I am having trouble posting pictures but I took the plugs out and checked wash and you can see the top of the piston has a nice shiny spot on it, but highs are 1/4 turn out. I checked out the boot and its at the second ring on the drive shaft so I will try the zip ties in the valley's and see how it works. I don't expect the boat to be a muscle craft with 4 people on it but to get at least up on plane would be expected.

now when I go to start it it beeps twice like always but when I hit the starts button it beeps 4 times at me and all the gauges light up! I thought its because it was low on gas but I put 5 more gallons in it and it still did the same thing. I know the gas gauge works. Any thoughts? Thanks again for all your help. Mike

 

[Mazdarx]

The 4 beeps means it's not in neutral or at least it thinks it's not in neutral.

 

[Brew Master]

The 4 beeps means it's not in neutral or at least it thinks it's not in neutral.

thank you, i figured it out yesterday and solved the safety switch issue