Problem with take off

[Bobbuff]

So I was finally able to run my 1998 Sportster 1800 again yesterday after replacing the throttle cable and it seemed to do very well. However, I honestly though it would be much quicker coming out of the whole and onto plane. It just seemed to drag even at high RPM's. Then when I would back off the throttle and do t again it would rev high but no results. Once again I would back off throttle and it would drag a little but the rise on plane. No clue what this could be. I have read on this forum about replacing the wear rings but I don't know if that is my problem????

 

[kicker]

Sounds like cavitation. If it is cavitation, it is either your wear ring or your carbon seal on the driveshaft.

Look inside your pump from the bottom of the boat or from the venturi side and try and get a measurement between the wear ring and impeller, it should not have more then 1mm gap. Check for damage to the surface area of wear ring and impeller





Check the condition of the carbon seal on the driveshaft, it might need replacing. Does water drip inside while standing still, if so, when you try driving forward it will suck air out of the hull causing cavitation It could also be that the rubber boot has slid back or does not have the strength any more to keep the carbon seal snug against the retaining ring.

 

[Bobbuff]

On your picture of the carbon seal the larger boat is loose. Where it goes over the actual carbon seal is where it is loose at. Could that be the problem and if so is this something that is difficult to replace and where would I even begin to get the parts. Also, I am pretty sure that the wear rings have not ever been changed just because the original owner didn't do any other kind of maintenance so my question would be how hard are they. I have read some other forums on this and believe I could do it but I am afraid of not having all the parts. Like when I pull off the assembly is there a gasket that I need to have. Also I have searched for the impeller removal tool on eBay and am not sure which one to buy. However, I think you are dead on what my problem is and I really appreciate you posting the pics as well that was really helpful. I would have not known where the carbon seal is.

 

[IDoSeaDoo]

The wear rings aren't hard to replace. The parts you'll need are the wear ring, the neoprene seal that seals the wear ring to the hull once it's replaced, and the impeller removal tool. I know the first two items can be purchased through shopSBT.com and MANY MANY other sites. The tool, I'm not sure about, but can def. be acquired on ebay. You SHOULD be able to remove the impeller by yourself with the tool, but I have a horror story about NOT being able to pull it off. There's a thread about it somewhere on here. You get the old wear ring out with either a sawzall, or a dremel with a router bit. I've even seen it done with a chisel. You basically cut a line down the side and pry it out. When installing your new wear ring be sure to put it in your FREEZER beforehand. Once cold, the new ring should literally just drop in. The carbon ring assembly can be bought from SBT as well, and is probably not a bad idea to replace. Upon re-assembly, make sure your driveshaft/impeller cone seal is in good shape, and that your driveshaft-end rubber bumper is in place.

I'm having the same issue as you with the cavitation, however, and I've already replaced both the wear ring and shaft seal. I'm thinking it's my impeller now. Will try fiddling with it this weekend. Your description of having to back off the throttle and punch it again sounds like dirty rave valves. Take them completely apart and gently clean the carbon off the guillotines with a brass wire wheel. This is a standard maintenance procedure and should be done AT LEAST once a season (depending on how often you ride). Good luck! PS, if you buy a premium membership here, you can d-load the manual, or search around online. They're out there

 

[Bobbuff]

I was literally just reading a post on how to clean the Rave valves when I got the notification that you responded. Thanks you again for the help I think that because my boat is older and I know the previous owner did no maintenance I am going to replace the wear rings and the impeller at the same time just to avoid having to take off the pump twice. I don't want to go thru the process and still not fix the problem plus I am sure it needs to be done. I will be cleaning my Rave Valves this morning and checking the wear rings and getting them ordered. Thank you for the help. I am getting excited that my boat is finally coming together. My interior will be here next weak which should be about the same time the impeller's and wear rings arrive. Thanks

 

[rjcress]

...I am going to replace the wear rings and the impeller at the same time just to avoid having to take off the pump twice....

I replaced the wear ring in my GTX (similar pump, just slightly larger) and found that process to be pretty straight-forward if you follow the directions on this forum.
http://www.seadooforum.com/showthread.php?30720-How-To-Changing-Your-Wear-Ring

While the pump was out I replaced the impeller with an aftermarket one that better suited my riding style AND got a pump rebuild kit to replace the bearings and other wear items in the pump (all parts from OSDParts, as they have nice kits).
If you know no maintenance was done, then you might consider whether you need to either rebuild the jet pump or have someone do it while it is out.
I chose to rebuild the pump myself, and wasn't able to get the bearings in just right with my normal shop tools, so I bought the pump bearing tool from Dr Honda. That tool and my friend's shop press made it a relatively easy job... although it did have one unexpected side effect... http://www.seadooforum.com/showthread.php?58788-impeller-cone-grease-absolutely-reeks!

Here's more info on the carbon seal and how that assembly goes together:
http://www.seadooforum.com/showthre...rbon-ring-seal-replacement-tutorial-by-chance