GTX Power Issue

[TitaniumMan]

Hi all,

As a new member of the board I am hoping other members can provide me with some needed advice.

I have a 1999 GTX RFI. I was having cavitation problems previously when taking the kids tubing. I replaced both the impeller and wear ring last summer. The cavitation problem disappeared, it pulled the tube effortlessly and I picked up an extra 4-5 mph in top-end speed.

Assuming all was right with the machine I decided to try water skiing behind it. Alas, it was unable to pull me out of the water on two skis. It didn't cavitate at all - it simply couldn't pull me up. I am not light (about 215 lbs) but assumed a 110 hp would be sufficient to haul my fat you know what out of the water. I realize pulling a water skier out of the water requires more power than pulling a tube but would have thought the SeaDoo would have done it effortlessly. To add insult to injury, my buddy's 1989 Kawasaki TS (no modifications whatsoever) pulled me up with no problem whatsoever.

Any suggestions as to what may be wrong with my machine or what I should do (other than lose weight!)?

I have posted the same query on the troubleshooting forum but thought I'd post it here as well.

Thanks in advance.

 

[ScubaDoo]

I noticed your seadoo has the VTS unit installed ...(Variable Trim System). To get the "best"pulling power I would suggest to put the VTS unit all the way in the down position. This would keep the noise of the doodown and allow it to pull your 215# lbs out of the water with ease. Also try to allow the skies to lay flat on the water and let the seadoo do the work of pulling you up on the skies. If you keep the skies pointing to the sky, it will cause more friction on the water and is harder to get you on plane. Now go break a leg... and have fun! lol

ScubaDoo

 

[TitaniumMan]

Thanks ScubaDoo.

Alas, the 1999 GTX RFI does not have the VTS unit installed (I didn't even realize it was available on the 1999 model).

I take your point regarding allowing the skis to lay flat and how that will result in less drag. Another guy suggested I simply do running dock starts (which is not an option).

However, my point is that the 1989 TS pulled me up almost effortlessly and I was doing nothing different (i.e. same skis, same stance, etc) than I did behind my SeaDoo.

Another suggestion I was given was to replace the head with a higher compression aftermarket head. Apart from this being way beyond my capability I find it hard to believe that the stock GTX RFI should not be able to pull me up with the factory head.

Any other thoughts would be greatly appreciated.

Thanks again.

 

[ScubaDoo]

I owned a Kawasaki TS and found it easy to pull a skier too. I looked in the manual for your 1999 GTX and it listed the VTS in that model. I don't think new head will help anything. What is the compression of the engine? it should be at a preferred rate of 150 psi. per cylinder. If it was less say 125 psi, it will still run ok but won't have the torque needed to pull you up. I'd do a compression check to see what the internals of the engine are doing. If you aren't sure how to do a compression check give us a shout and we'll give ya a heads on the proper way to perform one. I'll look further into the vts thing in the manual.

 

[TitaniumMan]

Thanks again ScubaDoo.

I will do a compression check (or get a friend to do so). I assumed because it was running so well with the new impeller the compression was fine. However your comment regarding the lower torque makes sense. The machine is at the cottage at present (probably under a foot of snow) so I'll wait until the weather is a little nicer.

In the interim, let me know about the VTS. There is definitely no vts switch on my machine and I couldn't find mention of it in the manual. Maybe it was an option mine didn't have.

Thanks again for your assistance.

 

[seadoosnipe]

Gsx....

ScubaDoo may have been looking at the GSX model, there were so many made that year, but your model is not equipped with the VTS system. It's so hard keeping up with all the models from years past. Especially in 98 and 99. There WERE so many.:cheers:

 

[ScubaDoo]

Thanks for the correction seadoosnipe. I hate to give incorrect information out. I tried to pull the manual back up and my connection kept dropping me off. That manual does list a lot of models.

 

[TitaniumMan]

Thanks again seadoosnipe and ScubaDoo.

I recall when I was buying the machine having difficulty sorting through the various models from 1998 and 1999 to determine price ranges.