Allyfishing
Well-Known Member
I've been doing a lot of reading since I bought this boat (actually before as well) on this board as well as any other forum I can find that talks about our boats and there were two good questions asked over on BBC regarding jackplate height and trimming on the 21 footers.
How high can ya run the motor and at what trim?? Great questions and some great advice given. One in particular was from Lee Sanderson on his experience with the 21's and how he accelerates and the method of slowing down. Here's his response to Manny:
"Manny,
7 to 7.5 is the max trim I've ever gone to with the engine at the ultimate height.
What I normally do is leave the jack plate between half and three quaters on the gauge until I get up enough speed to get the boat up on the pad. The trim usually ends up at about 7.5, (gauges may be a little different, do what is comfortable for you) then I'll start raising the plate, once the plate is up near full guage the bow comes up even more so I tap the trim down to about 7. I'll continue to raise the plate until the water psi drops to 20 and then I may bump the trim up or down once or twice depending on the load and feel. When I come up on a wake or get ready to slow down, I'll start lowering the plate and letting off the gas then adjust the trim as needed. I found several years ago that the 21's react better while slowing down using this method. It gets the skeg deeper in the water for better steering and does not drop the bow in as to create a bow steer problem like can happen by trimming down and letting off while leaving the engine elevated.
If you are able to trim to 9, the engine height is most likely way low. I have ran them at full trim, (10) just playing around. The bow is way too high and the tail is dragging leaving a lot of speed and better handling on the table due to the engine being too low.
Now to cover my rear side a little more.
This is just my opinion and what I've experienced personally.
The trim gauges will not all be the same so do what feels comfortable to you."
I have not started alot of posts but have chimed in here and there asking questions (hope I didn't offend anyone hijacking a post) so I figured its time for me to start asking questions.
In that quote Lee mentioned numbers for trimming. I'm guessing its with the newer engine with the smartcraft gauges. I've read and been told the engine trim should be either level or even slightly negative in relation to the pad at top speed. He also mentioned raising the JP while running and bumping the trim as needed til water pressure drops to about 20PSI. How high can ya go while running?? I marked my JP gauge at 1/2" under pad, even with pad and 1/2" above pad. I marked my trim gauge to be level with the pad or neutral.
Since I have an older style (fresh rebuild, which BTW, thanks to some here I got the kinks worked out) 225 Promax I feel I am treading on different ground. Most everyone else has 250 ProXS's, 225 SportXS's or 300's. I have a Brucato ACU with the rev limit raised real high and Todd propped me with a QIV-OT 26P to hit 6750RPM's. I only broke into the 80's once with it in the low 6000RPM range cuz I got real squirrelly and the port side raised up a bit. That's when I was told by a good buddy Don (F2008) to weigh everything on each side of the boat so I bought 3-25LB bags of shot (yup, about 80LBs too heavy on my side) for the port side when I get to go back out again.
Any and all advice is greatly appreciated. Especially any advice from guys with the older style 225PM's on a 21 footer.
And Lee, if you read this, thanks for that advice to Manny. I've read stories of what not to do to slow down so ya don't get wet, but never put the way you did to slow down with the 21 footers.
Thanks to any and all replies and to a great family of owners!! (Sorry this was so long)
Craig :big grin
How high can ya run the motor and at what trim?? Great questions and some great advice given. One in particular was from Lee Sanderson on his experience with the 21's and how he accelerates and the method of slowing down. Here's his response to Manny:
"Manny,
7 to 7.5 is the max trim I've ever gone to with the engine at the ultimate height.
What I normally do is leave the jack plate between half and three quaters on the gauge until I get up enough speed to get the boat up on the pad. The trim usually ends up at about 7.5, (gauges may be a little different, do what is comfortable for you) then I'll start raising the plate, once the plate is up near full guage the bow comes up even more so I tap the trim down to about 7. I'll continue to raise the plate until the water psi drops to 20 and then I may bump the trim up or down once or twice depending on the load and feel. When I come up on a wake or get ready to slow down, I'll start lowering the plate and letting off the gas then adjust the trim as needed. I found several years ago that the 21's react better while slowing down using this method. It gets the skeg deeper in the water for better steering and does not drop the bow in as to create a bow steer problem like can happen by trimming down and letting off while leaving the engine elevated.
If you are able to trim to 9, the engine height is most likely way low. I have ran them at full trim, (10) just playing around. The bow is way too high and the tail is dragging leaving a lot of speed and better handling on the table due to the engine being too low.
Now to cover my rear side a little more.
This is just my opinion and what I've experienced personally.
The trim gauges will not all be the same so do what feels comfortable to you."
I have not started alot of posts but have chimed in here and there asking questions (hope I didn't offend anyone hijacking a post) so I figured its time for me to start asking questions.
In that quote Lee mentioned numbers for trimming. I'm guessing its with the newer engine with the smartcraft gauges. I've read and been told the engine trim should be either level or even slightly negative in relation to the pad at top speed. He also mentioned raising the JP while running and bumping the trim as needed til water pressure drops to about 20PSI. How high can ya go while running?? I marked my JP gauge at 1/2" under pad, even with pad and 1/2" above pad. I marked my trim gauge to be level with the pad or neutral.
Since I have an older style (fresh rebuild, which BTW, thanks to some here I got the kinks worked out) 225 Promax I feel I am treading on different ground. Most everyone else has 250 ProXS's, 225 SportXS's or 300's. I have a Brucato ACU with the rev limit raised real high and Todd propped me with a QIV-OT 26P to hit 6750RPM's. I only broke into the 80's once with it in the low 6000RPM range cuz I got real squirrelly and the port side raised up a bit. That's when I was told by a good buddy Don (F2008) to weigh everything on each side of the boat so I bought 3-25LB bags of shot (yup, about 80LBs too heavy on my side) for the port side when I get to go back out again.
Any and all advice is greatly appreciated. Especially any advice from guys with the older style 225PM's on a 21 footer.
And Lee, if you read this, thanks for that advice to Manny. I've read stories of what not to do to slow down so ya don't get wet, but never put the way you did to slow down with the 21 footers.
Thanks to any and all replies and to a great family of owners!! (Sorry this was so long)
Craig :big grin
