2004 Polaris Msx Turbo150 Jet Ski. Cranks and runs just fine but won't rev up.

An ignition component is gittn hot from wear..buy a shop manual n test um

if there is a cable on the end of the lever , replace the cable assembly
if the lever is direct connection, spray with an anti rust penetrant on a regular basis for a few days then try to move it
try using localized heat from a butane torch to break the rust / corrosion seal while trying to move it

Try this:

http://www.polaris.com/en-us/company/help

check the ht wires are good as they stretch and break ! check fuel pump diaphrams not hard !

this is a car forum.

ok, the fuel is bad.. toy vehicles, fail that , top #1 fail.

Fuses in the electrical box?

sparks ? compressions 100psi or more ? water in fuel ? injecters clean ?

You might want to post this question in a different section. This is the computer games section.

You are deal with moisture corrosion in your carburetor. Take the carb off and clean it paying attention to the corrosion on the rubber tipped needle. Also open your electronics box and make sure that it is dry.

Tools(1) A compression gauge (2) a spark gap tester.(3) A Clymer service manual for your engine. (you can purchase from your local dealer. I know all these are expensive but if your going to be a polaris tech you will always need them. Troubleshooting (1) check compression. Look at your Clymer manual for specific psi.all cylinders need to be over 100 lbs and equal each other within 5 lbs.(2) check spark. use a spark gap tester all cylinders should jump a half inch gap. if you have good compression and good spark, fuel is the problem nine
times out of ten.Ethanol gas is proven to stay stable in fuel systems for only 30 days in 90 + degree heat. Drain gas tank,clean fuel lines replace and replace all fuel filters. Polaris has a gravity filter under seat, clean it. Finally replace spark plugs, I know spark plugs probably don't look bad but this is a C.D.ignition. Fresh spark plugs means less resistance for the ignition system. The ignition system is week compared to automotive. Test drive polaris, if the problem is still there then there is further steps to take. If your polaris is fuel injected. Pull out your clymer manual. what is great about the Clymer Manual for Novice techs is it gives detailed info on your polaris. Troubleshooting tips and teaches you how your polaris works. If its carburetor then you should clean carburetors. Inside the carbs is another filter that needs to be cleaned. Its not difficult you just make sure you put everything back in proper order. take pictures if you need to.