25" vs. 30" Single Outboard on a Bracket - 23SF

Snookerd · #1 03-31-2010, 04:46 PM

I am doing some research. I plan on going to a single 250 in the future. I was in the school that it had to be a 30" motor. I noticed that Capt. Chuck has what appears to be a 25" on his Hermco bracket. Anyone else have a single 25"? My twin 225's are 25" and it would give me the option to use one of my current motors.

Blue197320 · #2 03-31-2010, 08:47 PM

i dont know how much help this would be but, on my brothers 23 dusky hes got a stainless marine bracket and had twin 25" 200's. he ditched those and went with a single and needed a 30". you will probably need a 30" also.

kneedeep · #3 03-31-2010, 09:25 PM

i'm running a 25 inch 225 etec on a bracket and it's working out great. but if i fished in the real nasty stuff i would feel a little safer knowing my power head was 5'' higher with a 30'' shaft motor. something to think about.

Capt Chuck · #4 03-31-2010, 09:32 PM

Danny

If you have a Twin Bracket, you need a single 30" motor.
A Single flotation bracket requires a single 25" motor

hermco · #5 03-31-2010, 09:36 PM

The simplest explanation is when you mount twins they are higher than a single of the same shaft length because of the boats vee so they aren't too low and lose performance and create drag etc. As you go out from the centerline you have to go up with the motor/s. If you want to install a single on the bracket mounted at the twin engine heighth you will have to get a 30" shaft length motor. If you want to use one of your existing motors you can buy spacer/extension kits for most motors.

Snookerd · #6 04-01-2010, 11:07 AM

Quote:

The simplest explanation is when you mount twins they are higher than a single of the same shaft length because of the boats vee so they aren't too low and lose performance and create drag etc. As you go out from the centerline you have to go up with the motor/s. If you want to install a single on the bracket mounted at the twin engine heighth you will have to get a 30" shaft length motor. If you want to use one of your existing motors you can buy spacer/extension kits for most motors.

First of all-
Thanks for the replys everyone........So, the fact is that the height of the powerhead on a 25" motor on a single motor bracket would be lower because of being at the bottom of the "V" of the boat. The one variable not mentioned is the height of the bracket or does that not change? If it does change, then the twin bracket cannot be lowered as low on the transom as the single bracket due to being too wide to keep the tub of the bracket too close to the bottom of the boat. So, that causes the 25"motor to only work on the single motor bracket. Sound correct??

hermco · #7 04-01-2010, 03:21 PM

PM sent.

strick · #8 04-01-2010, 08:23 PM

The transom of the 30 inch bracket is taller then the transom of the 25 inch single engine bracket. If you were to mount a 25 inch motor in the center of a 30 inch bracket the anticavitation plate of the 25 inch motor would be obstructed by the transom of the 30 inch bracket. All flotation brackets are mounted as low as possible on the transom of the boat to gain maximum flotation when at rest. There are other variables as well for instance the deadrise of your bracket will influence the flotation chamber dimensions which will influence the mounting height of the bracket....for instance a bracket with a low deadrise and a wide flotation chamber may have to be mounted higher on a transom (as you eluded) where as a bracket with a steep deadrise and a narrower flotation chamber can be mounted lower on a transom. It all depends on the bracket dimensions and the boats transom deadrise. Most boats have a drain plug coming out the bottom of the transom which means you will have to mount the bracket just above this. Confused?

strick

kneedeep · #9 04-01-2010, 11:46 PM

this bracket is for a 25"motor.it is mounted 27 3/4" above the keel of the boat.the back of the bracket is 25"tall which puts the cavation plate of the motor at the bottom of the bracket. remember 1" up for every foot of setback. i went 1 3/8" up per foot. you could mount a 30" on a 25" bracket but you would have to mount the bracket 5" higher on the transom. by doing so you would lose all that floation not to mention the added wt. of the motor plus wet feet [image]

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strick · #10 03-31-2010, 10:24 PM

23sf with a Suzuki 25 inch motor single engine bracket. If you feel you need more flotation then go with the big Hermco bracket for twins. Of course the you have to think about how your boat will handle with the power head 5 inches higher...I really dont know if it would handle much different.

strick