1965-66 650 65 hp Mercury

[mrmarvc]

I have a '65-66 Merc. 650 65 H.P. outboard that don't run right or good when warmed up for a minute or so.Put in new plugs, completly cleaned carbs, new gas-oil mix, new distributor cap. Starts good the first time, but after the second or third time of start and stop, two of the four cylinders don't seem to run good or fire just right. and the motor is a little harder to start. Could the bushings in the distributor, or whole distributor be wore enough to chane the spark or timing after the motor starts to warm up? I'm at my wits end, can anyone help me?

 

[DJ]

Re: 1965-66 650 65 hp Mercury

marvc,<br /><br />I am not a Merc. expert.<br /><br />However, many times heat has an adverse effect on ignition coils.<br /><br />Does this engine have more than one coil? Do you know which cylinders seem to fade? If so, you can diagnose by switching coils around and see if the problem follows.

 

[mellowyellow]

Re: 1965-66 650 65 hp Mercury

pump the primer bulb and make sure gas is not leaking out the front of the carbs, this would indicate that you didn't set the float properly and could be causing it to flood on you.<br />the coil test is more likely gonna be your fix, but figured I'd give you another possibility.<br />good luck!<br />M.Y.

 

[Gold Bear]

Re: 1965-66 650 65 hp Mercury

marvc <br /><br />I would check the idle screw mixture. Turn the idle mixture screws out 1/2 turn and see if this improves the situation.<br /><br />Good Luck, Godl Bear

 

[RICKRICK1]

Re: 1965-66 650 65 hp Mercury

Two things have you checked your spark plug wires? And are the carbs securely tight at the block. I dont think it is your distributor as it is a magneto and they tend to work or not work at all. You did say you replaced the distributor cap so I think you need new spark plug wires, you did not say you had replaced them, but if so did you use marine plug wire or automotive wires.<br /> <br />Hope this helps.

 

[Troy_from _Oz]

Re: 1965-66 650 65 hp Mercury

could it be that the float is sticking in one of the carbies (hence two of the cylinders not running right)? Maybe tap on the side of the float bowl on each carby and see it that helps.<br /><br />cheers - troy

 

[mrmarvc]

Re: 1965-66 650 65 hp Mercury

To all that replyed to my posted question about my '65-66 Mercury 65 h.p. outboard, Thanks so much for your help and suggestions. I did not replace the plug wires, so will do that, and will check the coil, as that I didn't even think of them. May pull the carbs and recheck the adjustment of the floats. I also just found out that I will need to replace the seals on the lower end unit, as I pulled the plug last night and the oil was milky, after the oil was already changed early this fall. Again, THANKS for the help. marvc