I have a1973 evinrude motor 65hp i full throttle it and it seem ok the very first five min.

Question

and then it started to buck i let go the throttle it stop. any ideas im thinging it the plugs.

Answer 1

Did you follow the advice you got in your last question?

You can either guess what's causing your symptoms and throw parts at it until it runs, or else do some basic troubleshooting and just fix what's wrong.

Your choice.

Answer the questions I asked in your last question.

Answer 2

Jtexas is right.  This engine has a history of "dropping a cylinder"  which is another way of saying due to mechanical failure the rings and or piston head, or rods fail causing engine failure.  If caught early sometimes the power head can be repaired, otherwise it's junk.  It is also prone to problems relating to No lead fuel and low octane common today. It is 35 years old. Listen to the experts like JTexas!  Good Luck!