Prop change with altitude

[jiff7210]

I have a 1997 evinrude 150 on a 18'3 bass boat. I recently moved from north Carolina (100 ft elevation) to Texas where the elevation is right at about 1000 ft. At wide open throttle I am only reaching 4900 rpm. My question is, do I need a smaller pitch prop with just 1000 ft elevation change? Thanks for the help guys. Maybe it's a stupid question but knew I could find some experts here.

 

[metriccrescentwrench]

What rpm's were you seeing before? You won't be losing any significant amount of power at just 1000 ft., you'll need to look elsewhere for an explanation for the poor performance.

 

[Chris1956]

Especially with that 150HP on that light boat. What is your prop pitch?

 

[jiff7210]

Hey guys. Thanks for the responses. Some background:

I have rebuilt the carbs, changed fuel pump and checked the timing.

The prop is a 13 1/2 X 23p. 18'3 bass boat.

 

[jiff7210]

Also, I was able to get up to 5300 rpm when i was at the lower elevation. We did a compression test today was @: 120,120, 115, 125, 115, 120

 

[Chris1956]

You are likely a little overpropped for that boat/motor combo. The new elevation saps a bit of power, exaggerating the issue.

 

[jiff7210]

Thanks Chris,

My local shop has a couple props they are going to let me try so hopefully that's my issue