no power under load ???

[ksuydam]

A friend asked me to post this as I don't know the answer.<br />He has a 55 evinrude looks like it could be mid 80s model. Someone had tinkered with it and now it has no power under a load( will not excelerate to get up on plane). But will excelerate on the muffs. <br />I know nothing more about the motor except telling him to check fire to plugs and to check compression on cylinders.<br />Is there anything else we can look for??

 

[JB]

Re: no power under load ???

Howdy ksuydam.<br /><br />You describe and engine that is either running on at least one dead cylinder (most probable) or has a severely restricted fuel supply.<br /><br />First: Disable each spark plug, in turn, while at idle. If the idle remains the same that cylinder is not making power (dead). If the idle drops or the engine dies, that cylinder is making power.<br /><br />Check if any dead cylinders make a hot, blue spark at least 7/16". No spark, that's the problem.<br /><br />If dead cylinder(s) have spark, squirt some premix fuel into the carb(s) for that cylinder. If idle picks up, overhaul that carb.<br /><br />Without a model number we can't tell you much more than that.<br /><br />Good luck.