'69 EV 6 hp Fisherman - high speed miss

[gcrandall]

Evinrude Model 6902M 1969 I use as a kicker motor for fishing. It has good compression, I rebuilt the water pump (new impeller/gaskets) new plugs, new points - gapped them,new condensers and it starts well and runs good except seems to miss from time to time at high rpm's. What could cause this?

 

[digimortal777]

Re: '69 EV 6 hp Fisherman - high speed miss

could be running a little lean maybe????

 

[JB]

Re: '69 EV 6 hp Fisherman - high speed miss

Yeah, GO. I agree, could be too lean.<br /><br />I do think, however that it is mored likely to be a plug wire arcing to the head or the block.<br /><br />You have a magneto on your '69 engine. Magnetos make higher voltage at high speed than at low speed. That could be making enough voltage to arc.<br /><br />Check your plug wires for pinholes around where they come close to the block.<br /><br />Good luck.

 

[gcrandall]

Re: '69 EV 6 hp Fisherman - high speed miss

Thanks for the suggestions these both sound very logical - I will look over both of these possibilities over this upcoming weekend!<br />I Appreciate the help!

 

[gcrandall]

Re: '69 EV 6 hp Fisherman - high speed miss

Just checked it over carefully. Ohm's readings are fine on the plugs & coils. I checked the wires and they are solid. When checking over the newly installed points, I discovered that one was perfectly .020 and the other was just barely opening - way under .020. This must be the problem. According to the service manual a high-speed missing could be caused by incorrectly adjusted points. A plug broke when I dropped it checking the gap, once I put in the new J4C - I will determine if this was the problem. Thanks for the help.

 

[gcrandall]

Re: '69 EV 6 hp Fisherman - high speed miss

Checked the motor out last night and it is running really well. The gap setting on the one set of points was the problem. It runs smoothly now at slow, moderate and high speeds over an extended period. Thanks for the suggestions digimortal777 and JB !