nphilbro
Petty Officer 1st Class
- Joined
- Dec 19, 2011
- Messages
- 304
For what it's worth, I've posted before that I was getting a bit frustrated with the boat/motor performance I was getting from my Johnson 140 (good boat, good motor, not good together). Sluggish hole shot, trouble holding and sloppy plane at cruise speed, 4500 rpms required for hull cruise speed, poor/bad efficiency, taxing the motor.
I decided to power up to the max rating for this hull to the full 200hp. The difference was like night and day. This boat knows what she wants and she wanted this! Even though I still need to raise the motor another 4-5" (CMC 6x6 jackplate installed when I hung this) because the prop is buried, she found a comfortable plane at 23mph (gps) running 3200 rpms. We burned 6 gallons of fuel in 2 1/2 hours and logged 17 miles which included running extremely gas sucking WOT 5-6 times in 1/4 mile spurts after about an hour of easy break in (1k-3k variance just to open and lube everything with a 30minute shutdown before starting into the higher speeds). I did a lot of throttle up and back/on/off plane so there wasn't a really good barometer of actual cruising efficiency, just overall observation. I had to increase the fuel line from 3/16" to 5/16" ID at the dock because it would starve out at 5k rpms (I brought spare hose just in case). The prop is just a 14 1/2 x 19 aluminum. Room for improvement there too.
More top speed is not what I was seeking, but of course I checked it! Tonight we hit 45mph with ease. My guess is that after I raise the motor and dig the exhaust housing out of the water 50mph should be no sweat (but really never needed). Cruising performance should also pick up even more as I begin to figure out the more nuanced correct trim settings. I also ran the fuel/oil mix a bit rich (35/40:1 with Seafoam) so backing it off to 50:1 might have some affect too.
To say this boat now has more power is an understatement. I mean, when I throttled up from 1/4 to 1/2 it would push you right into the back of the seat (1500-3500)! It was extremely responsive. The hole shot was instant, to the point it was more than I would ever need or use and more than enough to get a big man up on one ski quickly (once or twice a year, maybe).
If I see the improvements tomorrow that I'm anticipating from raising the motor, is there a consensus on going to higher pitched prop, like a 21, to increase cruising efficiency even more (22-25 mph)? There is plenty of HP and torque now and I'm closing in on achieving a better ride. Obviously I don't want to bog the motor down but there seems to be a lot of headroom to play around with.
1978 Evinrude 200hp
14 1/2 x 19 Aluminum Prop
19.9Ft Fiberglass
CMC 6" Jackplate Extension with 5 1/2" travel.
I decided to power up to the max rating for this hull to the full 200hp. The difference was like night and day. This boat knows what she wants and she wanted this! Even though I still need to raise the motor another 4-5" (CMC 6x6 jackplate installed when I hung this) because the prop is buried, she found a comfortable plane at 23mph (gps) running 3200 rpms. We burned 6 gallons of fuel in 2 1/2 hours and logged 17 miles which included running extremely gas sucking WOT 5-6 times in 1/4 mile spurts after about an hour of easy break in (1k-3k variance just to open and lube everything with a 30minute shutdown before starting into the higher speeds). I did a lot of throttle up and back/on/off plane so there wasn't a really good barometer of actual cruising efficiency, just overall observation. I had to increase the fuel line from 3/16" to 5/16" ID at the dock because it would starve out at 5k rpms (I brought spare hose just in case). The prop is just a 14 1/2 x 19 aluminum. Room for improvement there too.
More top speed is not what I was seeking, but of course I checked it! Tonight we hit 45mph with ease. My guess is that after I raise the motor and dig the exhaust housing out of the water 50mph should be no sweat (but really never needed). Cruising performance should also pick up even more as I begin to figure out the more nuanced correct trim settings. I also ran the fuel/oil mix a bit rich (35/40:1 with Seafoam) so backing it off to 50:1 might have some affect too.
To say this boat now has more power is an understatement. I mean, when I throttled up from 1/4 to 1/2 it would push you right into the back of the seat (1500-3500)! It was extremely responsive. The hole shot was instant, to the point it was more than I would ever need or use and more than enough to get a big man up on one ski quickly (once or twice a year, maybe).
If I see the improvements tomorrow that I'm anticipating from raising the motor, is there a consensus on going to higher pitched prop, like a 21, to increase cruising efficiency even more (22-25 mph)? There is plenty of HP and torque now and I'm closing in on achieving a better ride. Obviously I don't want to bog the motor down but there seems to be a lot of headroom to play around with.
1978 Evinrude 200hp
14 1/2 x 19 Aluminum Prop
19.9Ft Fiberglass
CMC 6" Jackplate Extension with 5 1/2" travel.
