Heres the problem when i first got the motor i put it on my boat a 1652 alweld ribbed jon boat ran about 27 with just me and about 23 with me a buddy and a hunting load.

Prop wore out (wouldnt go more than 7 mph or plane out) so got another one 11x10 hex
Since then iv ripped the old soggy wood floor out which lightened the boat a good bit. But am seeing much lower speeds with just me a small generator and my flounder gigging set up im pushing 18-19 iv tried all sorts of different trim positions and adjusted everything in the boat weight wise.

Could it be a bad prop??


Also when boats on the trailer i hear a weird noise coming from the lower unit kinda like a scratching grinding noise but their is no belt slack or pulley wobble that i have noticed.

Is it possible a bearing or something went out and is causing drag an slowing me down. In the water it runs just fine still pushing 3500 rpms. And their was a good bit of grease in the unit.


Any ideas

27 seems pretty high for a stock motor on a ribbed bottom boat. At 3500 rpms your not going to see 27 mph. Your speeds dont seem to far off 18-19mph @ 3500 Check your out of water rpms and adjust governor so you hit 42-4300. On a stock motor I was turning a big blade 3800 bout 21-22 mph. How many hours do you have on the motor. It may be time to work the heads valves are prob leaking

Close to 200+ hours an with decoys up in front of the boat an just me i got 27 running across the bay to my spot

Maybe your gps was off a lil bit , I'm running a 1542 rivited hull weighs nothing with short sides and I'm running 28 by myself at 4700rpm carb, cam, exhaust done. but b4 mods was running maybe 18 mph