# 20hp vs 25hp



## firecat1981 (Nov 27, 2007)

I was at bass pro the other day and had a chance to look at the new mercs they had. They had a 30hp (I believe the same as a 25hp) and a 15hp (same as a 20hp). They didn't have them mounted to a boat, just on the rack so I couldn't tilt them like normally, but lifting them from there I felta huge difference!
The 15hp(20hp) felt just like my 20hp yamaha even from the awkward position, but the 30hp(25hp) felt much heavier! in fact it was actually difficult to tilt at all. 
On my last boat, the rear deck made tilting my 20 a little difficult but I was able to do it pretty easily still. My next build may have a platform which will make tilting tricky.

So I guess my question is to the guys that have 25hp 4-strokes, how hard is it to tilt?

Basically my budgeted choice will come down to either a fully loaded 20hp (electric start with power tilt) which weighs 130lbs+/-, or a basic 25hp (pull start and manual tilt) which weighs 160lbs+/-.

So is it worth the extra 5hp and 30lbs?


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## Brett (Jul 16, 2008)

When an outboard weighs almost as much as you do
then it's time for power trim and tilt or a power jackplate.
Otherwise all you're doing is setting yourself up
for some some serious medical bills. The human
anatomy is not designed for such off center loads.
I've already learned this the hard way, you don't have to.

:'(


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## anytide (Jul 30, 2009)

like he said -your at the point of either go big or go small -a loaded 30hp?
i would go with a 25hp manual 2 strk @ 115# just to keep it light and skinny
good luck fcat -anytide


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## firecat1981 (Nov 27, 2007)

2-strokes are not in my field of vision, otherwise this would be an easy choice. I'm a 4-stroke man now, I've had a taste of fillet minion and I can't go back to hamburger 

This would be a really easy choice if the 20hp had T&T instead of just power tilt.


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## Brett (Jul 16, 2008)

Buy the simple no option outboard
then get a combination t-n-t jackplate?

:-?


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## anytide (Jul 30, 2009)

> Buy the simple no option outboard
> then get a combination t-n-t jackplate?
> 
> :-?


x2 there ya go -anytide


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## firecat1981 (Nov 27, 2007)

I was thinking about that, and could do it with the 20hp, but an aftermarket T&T unit is 27lbs or more and adds like 6 inches of setback, and then I don't get the electric start and higher amp alt. Power tilt only adds 10lbs to the 20hp. 

Anyone ever use a power tilt? I know on a T&T you just hit the buttons to raise or lower, but on a power tilt do you have to unlock the motor before hitting the buttons? and what happens if you start dragging the motor on the bottom?


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## Brett (Jul 16, 2008)

Power trim and tilt is a necessity on any engine
weighing over 125 lbs. Allows you to adjust thrust
angle to fit every situation. Bow up for running "down hill"
bow down for cutting a chop, trimmed out for absolute top speed.
Still has a safety valve that allows the engine to kick up
if an object makes contact with the lower unit.
Perfect trim angle to fit all situations including shallow water drive.

You need to go for a ride on a boat with "all the bells and whistles"


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## firecat1981 (Nov 27, 2007)

Just looked up T&T units, I'd be looking at $500 or so so it's not to bad. It's a hard decision.



> You need to go for a ride on a boat with "all the bells and whistles"


I have been, I was on our rescue boat just recently, which has a 40hp yammi 4-stroke, it's real nice, but bells and whistles get expensive and I've got a 3k budget.


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## JaredFacemyer (Jul 29, 2009)

im not positive but for power tilt, im pretty sure you dont need to unlock the motor you just have to be under a certain number of rpms. not absolutely sure though


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## firecat1981 (Nov 27, 2007)

> im not positive but for power tilt, im pretty sure you dont need to unlock the motor you just have to be under a certain number of rpms. not absolutely sure though


if thats true, that would be great! I just don't want to have to reach back everytime I need to tilt the motor, if I'm gonna do that I might as well just pull it up then.


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## crozb (Sep 17, 2007)

I have a 20 hp Honda on my classic. I bought a CMC TnT and the boat performs awesome. If you call CMC you can save money with factory seconds if they have them. I saved about $125.00 and could not tell it was a second. You can mount the toggle switch anywhere you want. It's really nice when fishing new waters and need to tilt fast.


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## mark_gardner (Mar 18, 2009)

i had a 25 merc 4 stroke on the mud minnow and while it was a smooth motor, quiet, started 2 pulls everytime etc... i found it to be a real pita to tilt and having to position myself under the poling platform to get a good grip for pulling didnt make it any easier  i have since gone back to the 2 stroke due to its simplicity and lite weightness and i swear its got more balls than the 4 stroke ever did  to add a tilt unit would just add to the extra weight but no doubt that its something you really need to have with such a motor so now add the weight difference in the 2 motors plus additional weight of a tilt unit plus the set back and you'll see why i'm stuck on the 2 smoke till something better comes along


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## firecat1981 (Nov 27, 2007)

Well now I'm thinking about either a 25hp with a seperate trim and tilt unit, or a 25hp with built in TNT. Either way I'm looking at about 180-200lbs. 
Or I can stick with the 20hp at 120lbs and add the TNT which would make it 145lbs.
Then there is brand to consider 
For the 25hp:
Tahatsu/nissan/merc - I'd get the merc for the controls, but it's fuel injected and I'd rather have a carb and avoid extra ethanol issues.
Suzuki - V-twin, carbed, but no trim and tilt available, but pretty light motor.
Yamaha - Probably the best built motor and carbed, but usually more expensive and the heaviest.
Mind boggling   :-?


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## firecat1981 (Nov 27, 2007)

Also has anyone ever used a motor with gas assisted tilt? was it really that much easier?


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## paint it black (Nov 3, 2007)

Mine is pretty easy.
I just hit the switch and it tilts...................


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## Brett (Jul 16, 2008)

Gas assist made it easy to tilt the 35 hp Evinrude jet
and the 48 special (same block, different lower unit)
Flip the selector and grab the top rear of the cowl with
one hand and the engine would tilt right up.
Only problem was the plastic connector on the selector cable,
had a couple break over the years, got used to carrying spares.

plastic connector...part number 48 in link diagram

http://www.crowleymarine.com/johnson-evinrude/parts/48739.cfm


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## firecat1981 (Nov 27, 2007)

ok well then this adds a 3rd option into the equation. Would it be worth getting a 30hp with manual start and a gas assisted tilt? Since the 30hp is roughly the same as a 25hp I assume the weight would be as well?


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## paint it black (Nov 3, 2007)

Why not get an electric trim and tilt and not have to worry about it?


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## firecat1981 (Nov 27, 2007)

> Why not get an electric trim and tilt and not have to worry about it?


If you are talking about the 30hp then money comes into play as they are fairly pricey even without TNT.
If you are talking in general then it's a weight issue.
Example: a manual 25hp merc weighs in around 157lbs if I remember, but add a starter and TNT and now it's a portly 192lbs. 
That's 35lbs hanging on the very back of the boat, and in some cases can adversly effect it, But I'm working on a new design and some new draft calculations to work it out.
Now if you mean a seperat TNT unit, well that is an option and weighs about 10lbs less, but it would setback the motor about 5 inches which would shift the center of gravity back and negate the 10lbs savings. I have some math to work out.


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## firecat1981 (Nov 27, 2007)

ok I've been working on some rough design calculations to help me work it all out and it's looking good so far. These figure assume a well balanced load.

Here's the numbers I came up with for my old boat. Now keep in mind it was a flat bottom boat except for the small v up front, it was also hard chined as to maximize stability and draft. The tunnel in the rear actually made it draft more so I subtracted it when doing the surface contact area. I'm not calculating the compound curves or anything, just using rough numbers, the surface area was actually more then I'm basing the calculations on. You'll knotice I also based it on 14ft, yes the boat was 16ft total with the transom pitch and bow, but the bottom was 15ft, and my bow had a slight rise up front so I took a ft off for it.
I also estimated the hull to be about 100lbs heavier then it was to give me a large margine of error.









Next I calculated my new design, assuming I build it with a similar hull profile, and no tunnel. It will also be a little wider and I may push it a few more inches still. I estimated the hull weight to be about the same, however this boat may actually be lighter then the last due to the plans I have for it and reduced sheer.









So you can see by modifying the design I can use a much heavier motor and still draft roughly the same. 

Ummm can someone double check my figures as I did most of this at like 3am after getting back to the station from a fire  :-? :-/


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## firecat1981 (Nov 27, 2007)

Ok so I've determined a 25hp will be no problem on this boat. Now I also want TNT with it so here is the question to you guys. 
Would you rather have a motor with Factory TnT, or would you rather have a motor thats manual tilt and have a CMC TnT unit? It's about the same weight either way.


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## ko (Jun 9, 2007)

I have a MercHatsu 25 with elec start and power tilt (not trim) but can use the "tilt" at cruise speeds so it works as well as trim. I have to be close to WOT for it to shut off. Also have a TLT power jackplate and it is great as well. It is a great set up. I think I'd lean toward the bigger motor...


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## firecat1981 (Nov 27, 2007)

Thanks, I've already decided to go with the bigger 25hp motor with trim and tilt. I just can't decide if I want the tnt built in, or a seperate tnt unit. I'm leaning towards the seperate tnt unit cause then I can get the suzuki v-twin 25hp motor


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## jlee150 (Oct 29, 2009)

Gas assist is great in neutral, pita if your running, so you know an merc or yamaha that come with TNT do not kick up if you bump something running. The advantage of a CMC or other trim units is that when you do hit something it gives, the built in unit does not and the little spot your boat may have slid over is now off plane and your pushing. I agree with the two stroke for the weight, but 4 for fuell.
Ethanol is a problem only is you let the boat sit , it gums it up after sitting, but it's main problem is the fuel lines on your boat not the motor, 

Good luck!


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## Brett (Jul 16, 2008)

Most hydraulic assemblies have an integral safety feature.
It exists to prevent catastrophic failure under load.
It's called an overpressure relief valve, which allows hydraulic fluid
to bleed from the piston chamber to the reservoir instead of rupturing the system.
I believe that the overpressure relief valve is the reason
that outboard manufacturers do not recommend towing with the outboard
resting on the hydraulic rams when on the trailer.
Repeated road bumps could allow the outboard to change position
when you least expected or wanted it to.
The relief valve also activates when the lower unit hits a submerged object
and allows the outboard to kick up, instead of tearing it off the transom.


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## ko (Jun 9, 2007)

My MercHatsu 25 with Pwr tilt kicks up when you run aground. Sadly I have tested it a few times.


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## Frank_Sebastian (Oct 15, 2007)

Thanks for getting that information out there Brett. Also all outboards that I know about either function that way or have a mechanical release (those without trim and tilt or just tilt) that does the same thing if a solid underwater object is struck. Many run with mechanical release in the open position thinking that is best for hitting something. There is a reason for the lockdown as without it even striking a small object can cause the engine to flip up and slam down hard and you don't have any braking effect if you want to stop or reverse while maneuvering.

Best regards,
Frank_S


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