worked fine oneday,then took her out the next weekend and out of water RPMS are 4150, get in water, take off and wont go over 3300 rpms, no plaining out. What The Heck ?

thinking fuel issue,fuel filter has also turned blackish in color ?

any help is appreciated even from dog vest and shock collar aficionados

did u check ur plugs?

sounds like it could be a burnt diode on one of ur coils. engine will still turn up to full rpms on just 1 cylinder, but not under a load. obviously, the coil that ur tach is hooked to is firing. move ur tach to the other plug wire and see what it shows. if it reads then that one's firing too and u can move on to another issue. if it don't read it's prolly a burnt diode, easy fix if u can find a wiring harness somewhere.... i have changed out just the diode itself when in a pinch, but you'd have to disect the good one in order to match it then splice them back in.

good luck

i just went through the same sh!t with my mototr. check your fuel...very possible you have water in the carb. or else you have a bad spark plug wire. check to see if it is arching at all.