Under Propped Doing Harm?

[fpdiver]

125HP Merc Carb on 19' Trophy.

First, even though underpropped we never over rev. Alway keep it below 5000 RPM.

About 25% of our trips are very heavy and the 17" prop is great. The rest of the time the throttle is only about 3/4 full to achieve 4500-5000 RPM. Is there any harm to being underpropped if we live by the tach and don't care about the lost speed?


thanks

 

[j_martin]

Re: Under Propped Doing Harm?

125HP Merc Carb on 19' Trophy.

First, even though underpropped we never over rev. Alway keep it below 5000 RPM.

About 25% of our trips are very heavy and the 17" prop is great. The rest of the time the throttle is only about 3/4 full to achieve 4500-5000 RPM. Is there any harm to being underpropped if we live by the tach and don't care about the lost speed?


thanks

It'll be fine.

 

[Mi duckdown]

Re: Under Propped Doing Harm?

Good

 

[achris]

Re: Under Propped Doing Harm?

My preferred way of running... Save the engine from over working and you'll find the engine will last longer....

KUTGW....

Chris......

 

[emckelvy]

Re: Under Propped Doing Harm?

No harm at all, and you're far better off to underprop a motor than to overprop. Just be sure to keep track of rpm, this is a motor which does not like to be revved up beyond its recommended rpm range.

But as long as you stay in within mfr's recommendations, won't hurt a bit!

HTH............ed

 

[fpdiver]

Re: Under Propped Doing Harm?

thanks all....