1978 25hp evinrude problems with fuel system i think

hi everyone ,i was wondering if someone had some advice .recently bought this motor .cleaned carb ,no replacment kit, seemed very clean and fuel and air flowed thru. took it out tpady and was running well enough for an old engine than about hour or so into trip stopped running .got it started again but would only run on wot for couple minutes than went from wot to an idol while trhrottle was fully turned than stopped and now wont start.. plugs were very wet.
suspect my need new carby kit and sprark arrestor adjustment maybe?
any advice for me ,,
thanks very much.

Why did you pick on the carburetor first thing ??------What do you mean by " spark arrestor adjustment " here "-----Did you replace the water pump impeller ?----Did you operate the manual fuel pump when motor faltered ?-----Tried running with a borrowed fuel tank and hose ?---Checked spark ?----Checked compression ?---Mixing gas and oil at 50:1 in your tank ?

hi mate ,thanks for quick reply, lol thats what all us amatures do first haha carby,,in manual says theres an adjustment screw that is used for the spark timing?? but plenty of spark and all was running well for a while. ,not quite sure what that means , but checked spark ,good, checked compression .120psi on both cylinders , 50:1 fuel ..impellor replaced not long ago, if you mean the pump on the fuel line from tank i took off bung on carby and pumped it and fuel came out thru carby.. didnt check with another hose/tank but presumed that because the manual pump/primer bulb was hard that it wasnt the hose/tank

i was just looking at a carby repair online and noticed that he fitted a little clip to the float valve that attached to the float arm and mine did not have this on it so im thinking the last bloke left it off. this might be a problem .maybe the float valve is stuck in closed postion???? ..

Your thought is valid. The clip is there to drag the soft tipped needle off the seat. That is, assuming your motor has a soft tipped needle--which it should have.

However, that may not be the cause of your present problem.

ok mate thanks i will check flywheel key and all i can think of on weekend when i get new kit.

Will your spark jump a 3/8 " open air gap on a spark tester ??

sorry boobie have been away yeh plenty of spark jumps a long way and gives a good zap lol.

Ruptured fuel pump diaphragm?? As long as we are sitting here guessing, that is a good a guess as any.