1991 jetski runs great cold but once engine warms it runs rough. cleaned carb & new plugs.Can it be electric?

Question

yamaha waverunner LX, How do i check the electrical components? regulator, etc?

Answer 1

I've seen ignition coils break down when warmed up, the windings separate so take a look at those too. Also check for water in the fuel. Hope this helps

Answer 2

i doubt that its electrical on it try checking the compression on it when its cold then  run it and check it when its hot,i bet you see a big drop in it,and also squirt a little bit of oil in the cylinder and see if it makes any difference in it at all,you may have a bad head gasket on it,those was good for going through head gaskets,compare the compression on it ,and see what you come up with ,if there's a big difference in it you may need new rings or a head gasket,i used to own one of those and had to do the upper end of it a few times,their only good for a few years before you have to re-do them,good luck.