1985 Merc 60 cuts out while running full throttle

[jc60merc]

My 1985 Merc 60 starts, idles and runs good, but intermittently when running full throttle it will cut out and loose power. If you backoff the throttle, to an idle (or sometime just pump it) it will throttle back up and run fine again. This seems to only happen when the motor has run for a while and then sits. After sitting it will run full throttle for about 1/4 mile and then cuts out. I have rebuilt the carbs and checked all plug wires.<br />Could this be cause by a bad wire from the stater or a coil?<br />Can anyone help get me on the right track?

 

[hondon]

Re: 1985 Merc 60 cuts out while running full throttle

Sounds like you have an intermittant ignition failure .Most likely from a coil or a leaking plug wire.To test for these shorted units ,run this thing in the dark and look for any arching.There are other tests that involve pain and electrical shock that might help you ,but we'll let those wait.