sirofsirs

I'm trying to sort out a problem my grandfather is having with his 03 Polaris Genesis i. The jet ski has been running great until today. It idles great, nice and smooth, but when you rev it nothing happens. You can hear a difference in the tone of the engine, but the rpm doesn't change. It almost sounds like its starving of air or something. The engine doesn't stumble or anything when the throttle it used. I check the throttle cables which all seem to be fine. I was considering possibly the throttle position sensor. Could this be? Any other suggestions or quick fixes?

Also if you do give any suggestions and I need to look somewhere on the engine can you describe where on the engine? I know engines, but I've never worked on a jetski before. If your suggestion is the TPS, where can it be found?

Any help would be appreciated as its labor day weekend and we are trying to use it.

Thanks in advance and have a great holiday weekend,
Matt