Forget the health care debate, the financial crisis, or global warming. The real answers people want is how these engines compare on the same boat.
This weekend I had the oportunity to try these three different motors on my recently acquired Starcraft Sealite 14 aluminum cartopper. The boat is in good shape, has a maximum HP rating of 15, and weighs a claimed 142 lbs empty.
The outboards (all are 2-strokes):
1990 Mercury 8 hp
I got this along with the boat in an estate sale. It's near mint, very clean with no obvious wear. The seller said it has maybe 20 hours on it and I don't doubt the claim.
1978 Johnson 15 hp
I bought this motor slightly used in 1979 as a teen to use on my sea-flea. Being only 14 when I got it, speed was king and I used mostly at full-throttle for the next four years. In late 1983 it was winterized and put into storage for 25 years. It was serviced at a dealer this year before being started.
Late 1950's or early 1960's Evinrude 18 hp
Not sure of the exact year for this one, but it is the old-style round design. Like the Merc, this one has also had light use, and was recently serviced before running this weekend.
The test was done on the same day with the same driver, no load in the boat except for oars, a lifejacket, and a quarter tank of fuel. The Merc and Johnson started fairly easily after a few tries, then ran like new. The Evinrude was much harder to start but once it got going ran like a champ. Predictably, it was also the smokiest and loudest.
All three engines had great acceleration, with the 18 being the strongest, the 15 a very close second, and the 8 bringing up the rear (as you would expect).
Speed was the average of two directions, using a GPS device.
Mercury 8: 19 mph
Johnson 15: 24 mph
Evinrude 18: 25 mph
I was a little disappointed with the Johnson, I was expecting a bit more. A possible explanation is that it has the most use (maybe 250 hours) and it has never been decarboned (maybe someone can let me know how often this needs to be done on an engine).
The Evinrude 18 lived up to its reputation (in my neck of the woods anyway) as a strong motor. The loudness, along with the speed, made it the "scariest" at full throttle, despite being only 1 mph faster than the 15, which was a little more refined.
The big surprise was how close the Merc was to the others. Acceleration was also quite good. This may be due to the fact that its HP rating was at the prop, as opposed to the crank for the older motors. As the newest model it was slightly more ergonomically polished than the Johnson, which in turn was light-years ahead of the old Evinrude.
One more note on the 15: apparently OMC increased the power in 1981. according to the 1981 Evinrude brochure, that year's model included the tuned exhaust, but also changes to the compression ratio and timing, which may explain why some people who have modified older 15s or 9.9s with the tuned exhaust tube have not noticed a difference - it may have required the compression ratio and timing changes to be effective.
This weekend I had the oportunity to try these three different motors on my recently acquired Starcraft Sealite 14 aluminum cartopper. The boat is in good shape, has a maximum HP rating of 15, and weighs a claimed 142 lbs empty.
The outboards (all are 2-strokes):
1990 Mercury 8 hp
I got this along with the boat in an estate sale. It's near mint, very clean with no obvious wear. The seller said it has maybe 20 hours on it and I don't doubt the claim.
1978 Johnson 15 hp
I bought this motor slightly used in 1979 as a teen to use on my sea-flea. Being only 14 when I got it, speed was king and I used mostly at full-throttle for the next four years. In late 1983 it was winterized and put into storage for 25 years. It was serviced at a dealer this year before being started.
Late 1950's or early 1960's Evinrude 18 hp
Not sure of the exact year for this one, but it is the old-style round design. Like the Merc, this one has also had light use, and was recently serviced before running this weekend.
The test was done on the same day with the same driver, no load in the boat except for oars, a lifejacket, and a quarter tank of fuel. The Merc and Johnson started fairly easily after a few tries, then ran like new. The Evinrude was much harder to start but once it got going ran like a champ. Predictably, it was also the smokiest and loudest.
All three engines had great acceleration, with the 18 being the strongest, the 15 a very close second, and the 8 bringing up the rear (as you would expect).
Speed was the average of two directions, using a GPS device.
Mercury 8: 19 mph
Johnson 15: 24 mph
Evinrude 18: 25 mph
I was a little disappointed with the Johnson, I was expecting a bit more. A possible explanation is that it has the most use (maybe 250 hours) and it has never been decarboned (maybe someone can let me know how often this needs to be done on an engine).
The Evinrude 18 lived up to its reputation (in my neck of the woods anyway) as a strong motor. The loudness, along with the speed, made it the "scariest" at full throttle, despite being only 1 mph faster than the 15, which was a little more refined.
The big surprise was how close the Merc was to the others. Acceleration was also quite good. This may be due to the fact that its HP rating was at the prop, as opposed to the crank for the older motors. As the newest model it was slightly more ergonomically polished than the Johnson, which in turn was light-years ahead of the old Evinrude.
One more note on the 15: apparently OMC increased the power in 1981. according to the 1981 Evinrude brochure, that year's model included the tuned exhaust, but also changes to the compression ratio and timing, which may explain why some people who have modified older 15s or 9.9s with the tuned exhaust tube have not noticed a difference - it may have required the compression ratio and timing changes to be effective.