40HP Evinrude Bucking Problem

[Piker]

Last season my 40 HP Evinrude (1968?) started bucking something awful. At first it was occasional (once every 30 seconds), but then it increased in frequency to the point where I couldn't run with it. The first time it bucked so hard it spun the propeller hub. Any thoughts? Loose points? Lower unit problem? It didn't seem to be fuel related. Thanks!

 

[OBJ]

Re: 40HP Evinrude Bucking Problem

Hi piker...<br /><br />Could you please post your model numbr? Also, an engine can do funny things sometimes so could you describe a little what the "bucking" does. For example, if you go to full throttle, does it kick like your hitting something in the water or is it some other type of "jerk" for lack of a better word. Thanks.

 

[Piker]

Re: 40HP Evinrude Bucking Problem

I'm not sure of the model #. The motor jerks pretty hard - you can see it kick, but I wouldn't say as hard as if I hit something. Thanks.

 

[OBJ]

Re: 40HP Evinrude Bucking Problem

Does it buck all the time or only when in gear and running?

 

[Piker]

Re: 40HP Evinrude Bucking Problem

It doesn't buck in neutral, only when in gear.

 

[rolmops]

Re: 40HP Evinrude Bucking Problem

Hello.<br />Sounds to me that either the clutch dog is worn or more likely,the connections on the shift rod in the exhaust housing have some serious play in them causing the gear to disengage and then going back into gear again.The moment of disengagement causes a banging noise and the engine will buck to one side.Chances are that it is play in the connection in the top of the exhaust housing.<br />Time to get out the old manual and tighten those bolts.<br />good luck.

 

[Piker]

Re: 40HP Evinrude Bucking Problem

Yesterday I installed new points and condensers. I found that the green wire on one of the magnetos was rubbing on the shaft and the insulation was worn away. Could this have been the problem all along, or did this occur because of the constant bucking? I have not had a chance to test the motor yet.