2000 WAVERUNNER 1200 ENGINE REVS RPMS GO UP BUT IT WONT GO

I have a 1999 yamaha xl 1200 that has just had a new motor put in y the dealer. It revs but will not go foward or rev.

My 2003 XLT 800 runs great for the first 10 minutes. After that when I accelerate it immediately drops back to idle. Seems to run fine at idle but will only accelerate for second or two. Thanks.

Have you checked your impeller, even on the sandiest beach all it takes is 1 pebble to damage it. Its a common problem (all noise and no action) if it was a car you could liken it to clutch slip or wheel spin, when you take the impeller out the damage will be fairly obvious, ding marks on the leading edge and bent areas on the trailing edge. Solution :- Birmingham Screwdriver (Hammer) and cobblers last or tow hitch ball. Gently hammer out the bent bits and smooth the sharp edges off the ding bits (Both of these cause cavitation). This should get you back on the water within the hour. If this sounds a bit too much to have a go at then seek professional help. There are plenty of companies out there who can do the job, it's just a question of cost and time. Give it a go, you never know it might work.

Have you checked your intake underneath to see IF there is a clog in the unit? I have experienced that as well but in forward motion to where well bog my jetski down and give me maximum speed of 3 mph but high rpms. You may also wish to take off your grate and check further up in the unit.

95 yamaha wave runner wouldnt idle changed filter, spark plugs, kit in carburators..now idles good starts good will run 27 miles per hr for 20 minutes..was told maybe trigger coil or statter..not sure where they are located? wonder if there if a filter or screen in fuel tank?