Do outboard motors lose power just because they get old?

TinBoats.net

Help Support TinBoats.net:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

Wistex

Active member
Joined
Oct 5, 2011
Messages
26
Reaction score
0
boat #1 2006 1448 alumacraft jon with 2001 9.9 johnson manual start tiller on 15" transom-

boat #2 2010 1442 alumacraft jon with 1994 evinrude 15 electric start, long shaft, and remote controls on 20" transom-

the 9.9 always feels much more powerful so curiosity made me test hole shot and gps top speed with 325# driver.

15 hp on smaller, lighter boat; time to plane 8 seconds, top speed 18.5 mph

9.9 on the bigger jon; time to plane 6 seconds, top speed 19.5 mph

15 hp motor very quiet- starts easily- runs smoothly

9.9 motor quite loud in comparison- starts easily, runs smoothly

does anyone have an idea why the 15 doesn't readily outperform the 9.9?

should not one expect the 15 to outperform the 9.9?

could the 42" wide hull vs the 48" wide hull make the difference?
 
The ONLY way to figure it out is to put each motor on the same hull and test them both.

Also, new piston or both piston and rings in both would help to re-freshen the performance.
 
Heres my 2 cents on it. Boat#2 is going to be a bit heavier than boat 1. Because of electric start= battery, long shaft= little more weight. But with 5 more hp that should make up for that but since the boats are different widths the narrower one will ride a little lower in the water than the wider one(I think). Maybe the 15 hp needs a tune up and a compression test to see if it does need a rebuild.

Steve
 
Wistex said:
could the 42" wide hull vs the 48" wide hull make the difference?
narrower hull having a heavier load would sit lower in the water, that equates to more drag.

follow Pappy's advise and test both motors on the same hull.

to answer the question in your title:
it's not the age, but the amount of use (or abuse) that an engine goes through which will have an effect on the power. a well used motor possibly has less compression, weaker spark(?), propeller/gear/bearing wear and tear, etc. etc. all of which affect performance (in varying degrees). proper use/maintenance plays a big part on how long the engine stays in good running condition.
 
regarding the recommendation of trying both motors on both hulls, that would be very good. however the 15 is a long shaft with remote controls on the 1442 20" transom and the 9.9 is a tiller control on a 15" transom. so while the idea is good, it is very impractical and way too much work to answer the questions at hand.

thanks anyway.
 
Subject question:

"Do outboard motors lose power just because they get old?"


Short answer:

No, age has nothing to do with it, but usage will cause any internal combustion engine to lose power.
 

Latest posts

Top