Won't rev past 3500RPM Bogs down!

[92xp580]

:ack:

Hello
I was wondering if anyone might be able to give me some advice why my seadoo (92XP580) is acting up. It was cavitating badly so I changed out the pump with a brass 96 xp pump. It worked great for a while then all of a sudden the moter started to bog and now it wont go past 3500 rpm. It almost seems like the motor cant push the boat onto plain? Might be something totaly different but I have no clue what the hell it could be, when I first put it in it was way faster than before but had some trouble getting out of the hole, once on plane it was fine.

 

[kustomkarl]

Brass XP pump? If the pump is the correct pump it should be ok...I would check the wear ring for the proper clearance, an look to see that you re-assembled everything correctly. I would check too to be sure the impeller shaft isn't getting hot by the rear of the engine, it might not be aligned properly.

Check it out and post back so we can advise again.

Karl

 

[92xp580]

The wear wring has just been replaced. To give you the whole story I was at camp when a buddy took it for a spin he came back and said it was bogging a bit, i tried it and realized he broke something. I took the pump off and the wear ring was completely destroyed busted to hell. Changed it out and re mounted the pump but still runs like crap. The moter hasn't come out and it looks like the shaft is spinning true. I'm not sure that it is the pump but the motor seems to run and will rev to 8000 at like quater throttle out of water. shaft doesn't get hot but then again i havn't run it for an extended period as it doesb't go fast anymore. The gap between the impeller is about 1 16th on and inch max! and it spins freely, i rebuilt the whole thing myself. Pump is the same style as the OEM one same shape number of hosses ect and bolts up fine?

 

[kustomkarl]

I would pull the plugs out and at the rear of the engine, see if it the shaft spins freely, by hand. It could be a bearing bad in the pump. The engine would free spin out of the water with a bad bearing as it has NO resistance from the water.

Karl

 

[92xp580]

I will try it right now but im prety sure they are good. you are refering to the bering in the housing? when I changes out the wring I took that shaft apart and they looked good, spin smoothly, whole pump in fact spins smoothly by hand and starts and idles nicely, i don;t think anything is binding I was just thinking that maybe the pitch of the impeller is too agressive fore this old 60 motor? But then again why did it work fine for a month and now all of a sudden doesn't and it happened right when the wear ring took a nose dive!

 

[kustomkarl]

You answered you own question....I would do a compression test too. It could be that the engine is due for a re-build. If you need information on doing a compression test properly, let me know.

Karl

 

[92xp580]

I think that's what it has to be, she's just old maybe she just doesn't have the HP to push it anymore, when the problem first started it would get up to speed and then die back down here and there now it just won't get there at all but the motor sounds good and makes power out of the water I guess I will have to buy a new motor, no point I will just part her out and buy a new doo i guess thanks for your help

 

[kustomkarl]

I would do a compression test first....that will tell all. It just might need some rings and a hone maybe... It could be a inexpensive repair.

Karl

 

[92xp580]

thanks will do, any idea how high the compression should be?

 

[kustomkarl]

Here is some information on a compression test;
To test compression, remove both spark plugs. Place spark plug caps on the plug cap studs near the cylinder head to ground the empty caps. This completes the circuit of the ignition electrical system and prevents any electrical problems from the caps being un grounded. Using the correct adapter for the threaded end of the tester,( same length of the spark plug threads length)screw in the tester in one plug hole. Hold the throttle wide open. Push the start button. Watch the compression guage, when it peaks out at the most compression, let go the start button. Read the psi number. I would do it 3 times to be sure it is accurate. Check both cylinders the same way. The ideal compression is 150 psi per cylinder. If it is less, it's not a problem as long as they are close to being the same. If the psi is less than 90 it might need be time for a tear down and a rebuild. If the psi in 1 cylinder is say 140 psi and the other is 80 psi you need to tear down and repair. This difference is a lot then there is a problem. I hope this helps you.

Karl

 

[pawngod]

did you ever figure out the problem here??