Honda 5HP Motor "bump"

[webfoot]

I have a 1996 5-HP, 4-stroke Honda motor. Since a few months after warranty expiration, the engine exibits a defined "bump", every 15-seconds (exactly) at full throttle. It feels almost like the motor has just hit something in the water and can be felt throughout the aluminum boat hull. This only occurs at full or almost full throttle (with 5-HP, that is most of the time). We have tried duplicating the problem in a tank of water w/o success,,,it only occurs while pushing the boat. There are no other running problems with the motor and none of the Honda dealers that I've spoken to have ever run across this problem. <br />Any ideas/experiences out there?

 

[steelespike]

Re: Honda 5HP Motor "bump"

Dont know what shift dogs are like on a Honda<br />but it sure sounds like worn shift dogs to me.<br /> Maybe a Honda dealer would let you try another prop,could be something strange with hub.

 

[webfoot]

Re: Honda 5HP Motor "bump"

On the bumping Honda, have torn down the geartrain twice looking for wear, but none found. This problem started when motor had only 2 or 3 hours on it, but had run out of time warranty.