quackaddict1
Petty Officer 2nd Class
- Joined
- May 30, 2008
- Messages
- 138
Gentleman, after my last post concerning my 28hp johnson and it only getting to 5000-5100 rpm with a two man load and some fishing gear (prop is a 9.25 x 11 and boat is a 16ft crestliner deep V), I decided that the first step I should take was to add a jack plate to get the motor where it should be (the cav plate was roughly 2 inches below the bottom of the boat). While I was at it, I reinforced the transom and replaced the wood with an aluminum plate, I added about 20lbs with the jack included to the boat weight wise, but the transom has much much less flex than what it had, there was enough flex in it that with the new setup, I had to lower the pin to the second hole instead of the third hole, under load with the old it would flex enough to run at a 2 hole setting, if that makes sense.
After I installed the jack I got out on the water this morning, I used a couple of anvils to replicate a two man load + fishing gear. After moving the pin to the second hole from the bottom, the boat was noticeably quicker to plane, seemed to have more top end speed (no GPS) and wound out at 5300-5400 rpm. The motor would bite good doing everything except very hard turns at WOT, where it would break loose until I would straighten out or back off. At 3/4 throttle, it would not slip at all, and going straight and gentle turns were fine. There was a decent chop this AM on the big part of the lake, from my research I have heard that rough water and jacks can be a bad combo.
So my questions right now concern getting the motor to bite in the corners, and if possible still increasing the RPM's. I have attached pictures below of the current position of the motor on the transom, and some of the prop, I don't know if a chewed up prop will affect bite ( I would think so), so I have attached pictures to see if a prop in this condition will.
I have a couple options as of right now, the jack is set so everything is as low as it can go without reinstalling the motor, I can however move the jack out (make the jack wider by 1.5 inches or so) which should increase bite into the water. If you guys feel the prop is junk I can get a new prop, though I would change it to a 10 pitch to get more RPM's out of the motor. If neither of these are good enough I can lower the jack by reinstalling it.
After I installed the jack I got out on the water this morning, I used a couple of anvils to replicate a two man load + fishing gear. After moving the pin to the second hole from the bottom, the boat was noticeably quicker to plane, seemed to have more top end speed (no GPS) and wound out at 5300-5400 rpm. The motor would bite good doing everything except very hard turns at WOT, where it would break loose until I would straighten out or back off. At 3/4 throttle, it would not slip at all, and going straight and gentle turns were fine. There was a decent chop this AM on the big part of the lake, from my research I have heard that rough water and jacks can be a bad combo.
So my questions right now concern getting the motor to bite in the corners, and if possible still increasing the RPM's. I have attached pictures below of the current position of the motor on the transom, and some of the prop, I don't know if a chewed up prop will affect bite ( I would think so), so I have attached pictures to see if a prop in this condition will.
I have a couple options as of right now, the jack is set so everything is as low as it can go without reinstalling the motor, I can however move the jack out (make the jack wider by 1.5 inches or so) which should increase bite into the water. If you guys feel the prop is junk I can get a new prop, though I would change it to a 10 pitch to get more RPM's out of the motor. If neither of these are good enough I can lower the jack by reinstalling it.
