SparkieBoat
Captain
- Joined
- Aug 17, 2009
- Messages
- 3,643
I have a 95' 150 Intruder Evinrude GL model, on a 17.5 Mckee Craft. I can only spin a 19 pitch prop about 4250 RPMs at about 34 MPH. I ran some checks on what I should expect at this website.
http://go-fast.com/boat_speed_predictions.htm
I weighed the boat today, it is 3060 LBS including the trailer, motor, anchor,2 batteries, CC, and 15 Gallons of fuel and maybe about 40 lbs of misc stuff. I figure the trailer weighs around 500 lbs. I ran a check on this web site at 3000 lbs. with a 250 constant at 50 mph and it came up with 120 HP motor. Well my actual weight is probably closer to 2800 lbs fully loaded and I got a 150 HP. I fully expected to bust 50 MPH wide open. I expected to be purchasing a 21 or 23 pitch prop for the motor. I have checked compression, spark, cleaned carbs, new fuel pump, new intake manifold gaskets, new thermostats, I ahve been through this motor thoroughly and I can not figure out why it is not pushing better. with the intake butterflies about 1/2 open it is running about 4100 rpms and ab out 32 mph as I open it on up it begins to power up then just when I open it up all the way it acts like its getting ready to increase power for about a split second then just "bogs out" and settles in back at around 4100 RPMs, as I begin to throttle up if I stop just before wide open I can get it to around 4250 RPMs and 34 MPH. any ideas on what to check/test would be appreciated.
http://go-fast.com/boat_speed_predictions.htm
I weighed the boat today, it is 3060 LBS including the trailer, motor, anchor,2 batteries, CC, and 15 Gallons of fuel and maybe about 40 lbs of misc stuff. I figure the trailer weighs around 500 lbs. I ran a check on this web site at 3000 lbs. with a 250 constant at 50 mph and it came up with 120 HP motor. Well my actual weight is probably closer to 2800 lbs fully loaded and I got a 150 HP. I fully expected to bust 50 MPH wide open. I expected to be purchasing a 21 or 23 pitch prop for the motor. I have checked compression, spark, cleaned carbs, new fuel pump, new intake manifold gaskets, new thermostats, I ahve been through this motor thoroughly and I can not figure out why it is not pushing better. with the intake butterflies about 1/2 open it is running about 4100 rpms and ab out 32 mph as I open it on up it begins to power up then just when I open it up all the way it acts like its getting ready to increase power for about a split second then just "bogs out" and settles in back at around 4100 RPMs, as I begin to throttle up if I stop just before wide open I can get it to around 4250 RPMs and 34 MPH. any ideas on what to check/test would be appreciated.