Top End Power

[econdriak]

To start things off this is the first time that I have had to post at this forum for help. I have had my 97xp since 1998 and other than a corroded starter switch shortly after I purchased by boat, I have had no mechanical problems whatsoever. Earlier today I put the boat in the water to go for a ride and noticed that it was a little more difficult than normal to crank and once it got going it just did not seem to run smoothly. I started paying a little more attention. When i take off the engine will rev up to the high RPM and once the boat planes off the rpms decrease. Once I was up and going I noticed that there was no difference in rpms or power from 3/4 throttle to full throttle. This is not normal. I ran the boat for the first time this season two weeks ago and it ran like a champ. I did notice that there were a couple of times then that it sputtered but nothing to noticable in performance. Normally, I can cruise anywhere from 45-52 according to the guage on smooth water. Today I was running appx 35-40 at full throttle. In the low RPMS there was no dimminishment of power. The only lack of power came in the high RPMs. I did get a new set of NGK plugs today thinking that was probably the issue, but that did not resolve. Any thoughts. I seems as if it is bad gas almost, but we ran the gas that was purchased at the same time in another PWC and had no problems. I was thinking may a carb adjustment or a cable is sticking. (My choke cable froze 2 years ago) but I just give the throttle about 5-10 pumps before cold starting and have no problems. But I may speculate that I may be looking at a rebuild. I have not tested the compression yet, but I come back that it runs perfect in the lower rpms and has plenty of power. Any thoughts? Thanks

 

[seadoolover]

wear ring

This sounds like a problem with your wear ring in your jet pump rather than your engine. If you have too much gap between your impeller and your wear ring you get an increase in rpm but no more speed... check your wear ring for clearance.

 

[econdriak]

This sounds like a problem with your wear ring in your jet pump rather than your engine. If you have too much gap between your impeller and your wear ring you get an increase in rpm but no more speed... check your wear ring for clearance.

Thanks for the reply. However When I plane off the RPMs decrease to what it would be at 3/4 throttle. The power that I am getting is indicative of the RPMs

 

[seadoolover]

hmmm.

Ok so you get the same speed but can't get the extra power/ rpm increase last quarter of W.O.T. Inside the carb you will find a filter. change this filter and see how you go then. Possible clogged filter restricting fuel flow at W.O.T. [ Wide open throttle ]. Post back with results.

Also.. check throttle body is fully open on carby with throttle lever fully depressed [W. O. T.].. possible sticky cable or adjustment.