Motor hole position on a bracket 228

[SmokyMtnGrady]

Hey Guys,
I repowered in 17 and yes 5 years later I have not got the boat dialed in to what I think it should be. Mid Carolina mounted the motor on the top hole on the bracket and top on the motor. I ran it for 2 seasons like this. Then KY suggested moving it at least one hole on the motor . So, I did and it improved and max rpm with both SSII 3 blade and power tech 4 blade both cap out at 5400.
COVID came and screwed it all up and I got the boat back and the motor is now in hole 1 on bracket and 3rd hole on the motor. However, just looking at it ,it does seem high. With that said the antiventilation plate was below the surface while on plane at hole 2 .

Motor is 4.2 liter f250 25 inch shaft .

I think it will be ok on the 3rd hole but curious to see where y'all run your motors on that set up. I never paid attention to the original factory rigging as to what hole the 3.3 liter 250 was mounted. That's my core problem here.

What say you?

 

[seasick]

Exactly how did Covid reposition your motor?

 

[wrxhoon]

Smoky,
Mine is 2013 4.2, 250hp, factory fitted on the second hole from the top.
It may or may not be relevant to your boat because mine has the later model bracket that is longer and more volume so it may have more buoyancy. Mine looks about right but if I used the boat mostly on calm water, I would be tempted to lift it up one hole to test . I mostly use mine on the rough Pacific going up and down waves so I feel she will pick air .
KY has the same boat as yours with the 3.3lt waiting for his 4.2.

 

[magicalbill]

Exactly how did Covid reposition your motor?

I was wondering the same thing....

 

[glacierbaze]

I don’t know which hole is correct, but I was cleaning some irrelevant papers out of my owner’s notebook earlier today, and came across the Gil bracket paperwork. They said that a good starting point was with a straight edge which extended from the bottom of the hull, across the center of the water intake on the lower unit, and fine tune from there.

 

[Ky Grady]

The only way to truly know if you're in the right location is get out and run it. As you and I have discussed, mine is in the same location as yours is now. I've never blown out and get good performance in this location. My boat was setup by PO and he ran her in the GOM chop. I'm sure if it didn't do well there, he would have changed it back to the factory rigging, top hole in bracket, second hole in motor. The 3.3 is a bit heavier than your 4.2, but not enough to make a huge difference. Get out and run her and see how she does.

 

[seasick]

The only way to truly know if you're in the right location is get out and run it. As you and I have discussed, mine is in the same location as yours is now. I've never blown out and get good performance in this location. My boat was setup by PO and he ran her in the GOM chop. I'm sure if it didn't do well there, he would have changed it back to the factory rigging, top hole in bracket, second hole in motor. The 3.3 is a bit heavier than your 4.2, but not enough to make a huge difference. Get out and run her and see how she does.

If there is a bracket, the general rule is a bit different. For each foot of offset, lower the lower unit about one inch higher than without a bracket. Whether or not to adjust for any floatation added by a bracket depends on the specific bracket. The goal is to not burry the ventilation plate when on plane and trimmed

 

[Ky Grady]

If there is a bracket, the general rule is a bit different. For each foot of offset, lower the lower unit about one inch higher than without a bracket. Whether or not to adjust for any floatation added by a bracket depends on the specific bracket. The goal is to not burry the ventilation plate when on plane and trimmed

Yeah, we know all this. Smoky is just experimenting.

 

[SmokyMtnGrady]

Smoky,
Mine is 2013 4.2, 250hp, factory fitted on the second hole from the top.
It may or may not be relevant to your boat because mine has the later model bracket that is longer and more volume so it may have more buoyancy. Mine looks about right but if I used the boat mostly on calm water, I would be tempted to lift it up one hole to test . I mostly use mine on the rough Pacific going up and down waves so I feel she will pick air .
KY has the same boat as yours with the 3.3lt waiting for his 4.2.

Hey Wrx,
Whats the max RPM you are getting. I have yet to get my 4.2 to spin up past 5400. I have tried 3 blade yammy and a 4 blade power tech and both spin up to the same. My 3.3 would spin up to 6,100 . kY gets to that as well and he is on hole 3.

 

[wrxhoon]

I get 6000 trimmed out on calm water. I tried different props, Merc Enertia 17" the best overall, Enertia 18" very good too. The only reason I run the Yam 17" saltwater II, She reverses better, 4 blade Merc Vensura was good for that as well. I may add that this boat with the longer bracket reverses better than the old boat with the same prop.
3.3 has different gears,( 2.0 )you will get more revs using the same prop. 4.2 has 1.75.