235 HP - Evinrude - Rough Running

[captmk62]

1985 - 235HP Evinrude - Motor intermittently runs rough above 4000 RPM - (Never has a problem below 4000 RPM) Changed plugs, plug wires and fuel filter - No help - When it is running rough pressing the fuel bulb does not help - Sometimes it runs great at 5500RPM - When its running rough I think it is electrical but when it is running good I think it is a fuel problem. Any suggestions would be greatly appriciated.

 

[rabidfish]

Re: 235 HP - Evinrude - Rough Running

I would start with simple items that you dont need specifications for. <br /><br />First, if it runs well at most of the throttle range, lets take a look at the Hi-speed jets. On each side of the float bowls is a 7/16 bolt, with a slot(screwdriver) Remove the "bolt" then with a tool available from your dealer ( part # 317002 )(DON'T use a screwdriver) remove the jets, they are in the same hole. Make certain they are clean. Then put it all back together. <br /><br />Then check your spark, does it jump a 7/16th gap?<br />Check you spark plugs do they all look the same?<br />If so, change them, then run it again and see how it goes.<br /><br />Let us know how you make out.

 

[QuarterPound]

Re: 235 HP - Evinrude - Rough Running

You might have coil problems. On occasion they can go intermittenet before dropping. A quick plug check can id that problem. How old are your power-packs?<br />I have run a 235 Johnson for 16 years and know it can be fickle at times

 

[clanton]

Re: 235 HP - Evinrude - Rough Running

When the engine is at 5500 rpms, touch the up trim for 2/3 seconds. If the rpms drop 300 to 400 rpms and engine runs rough, the stator is bad. Check with meter before replacing.