Trouble Transitioning from Idle to Full Throttle

[Tao of Funk]

1976 70hp Evinrude
new carb kits, plugs, fuel lines, recifier, and cleaned nearly every electrical connection

It will idle fine when it's cold and I can feed the throttle in slowly (or abruptly) right on up to full throttle. Then when it's fully warmed up it'll have trouble taking the throttle from idle. It seems as though one cylinder fouls out and it can't accelerate past about 2000rpm. Then if I get it to a high idle and then "goose it" she'll run like a scalded dog. Once I get it run up to full throttle and slow it back down to idle I can feed the throttle back in slowly and she'll take it smoothly right back up to full throttle.

The real problem is getting her to idle for any period of time when she's hot. I adjusted the floats to lower the fuel level in the float bowl a bit but that didn't help.

If a cylinder is fouling why only when it's hot? How come when I get it cleared it'll function properly when hot? If it's rich at idle why will it run for a while and then foul up?

The carbs are fixed orifice type. The low speed orifice plugs are 30's (I assume 30/1000). THEY ARE CLEAN AS A WHISTLE!

 

[tashasdaddy]

Re: Trouble Transitioning from Idle to Full Throttle

check your spark, when warm, may have a coil that is heating up an failing.

 

[Tao of Funk]

Re: Trouble Transitioning from Idle to Full Throttle

That sounds like a winner. Can they still function well enough when hot to work in most conditions? My engine will run great when hot except when I idle it too long, then one cylinder seems to foul and wont return to normal operation until I get it back to full throttle.

Thanks!

GB