Well 1st off my boat will plane much faster and better than a 1436 due to the planning surface being wider,that's just science.I have had a 1236/1436/1442/1542 and now a 1648 and out of all the boats this 1648 gets up on plane in a blink of an eye.I have a fiber glass floor.I got that stuff from home depot,it's like pvc board,won't rot,stain,break,etc......It's fairly light,it probably adds near 100lbs to the boat give or take a bit.I was running me at 300lbs,friend at 200lbs,boat is 320lbs,motor is 115lbs,plus full tank of gas (6 gal),a small cooler,plus the floor at near 100lbs,so i'm probably over 1000lbs total weight.This is why i don't want to get rid of this outboard,it has just some insane,crazy power and imagine what a 25hp carb will do.All speeds were taken like 20 times by gps because i couldn't even believe what kind of speeds i was getting.With the 1000lb load i was near 28.5mph constantly,with just me in the boat and nothing else i was at near 30 to 31mph give or take a mph going with the wind or against it and it was porpoising so bad i had to put my 150qt cooler in the front and add near 150lbs of blocks i had at my house and that stopped it finally.Like i said i have 2 gps's and i'm telling you the speeds are accurate but insane.I just bought a brand new 13 pitch prop so we will see how that does.The one i have on there now is in good shape but i want it as a back up.onthewater102 wrote:That's a little insane that you get those speeds out of a 1648 with the 20hp...I barely get 28 with my 1436 and just me in it. I did all my decking out of lightweight fiberglass & with the motor & TM removed my brother and I can still pick my boat up & carry it, so I know it's not that heavy. Do you have any decking in the 1648 or is it a bare hull? Also, were you the first owner of the motor or is it possible you've got the 25hp carb already courtesy of a prior owner? I gave you the pics of the two carbs - if you're certain you've got the 20hp I think I've got some more tuning to do, though I don't see how b/c it runs beautifully from idle right up to WOT even in the dead of winter.
I have the 20hp carb also,here is the pictures.