Switching to Mercury 4 stroke

[PurpleHaZe]

Today just bought a new 25hp merc efi 4 stroke, putting it on a v 16 lunker. Old motor 1988 30hp johnson still is a fine motor just wanted to go 4 stroke for a few years, first impressesion of new moter was wow its freakin huge. Wll this moter troll down? My 30 did with alot of vibration The salesman said yes i dont always believe them .I know 4stroke are quite and use less gas.

Anyone have the 25 merc efi and could share some tips?

[idratherbefishing]

You will love the 4 stroke and it will troll down great. Enjoy it!

[PurpleHaZe]

Thanks for the response. Im getting real anxious to get this thing on the lake.

[broken_line]

same with me!! i cant wait to try out my new chrystler 25hp on my 13' duck boat!

[PurpleHaZe]

Thanks for reply. is crylsler the same as merc?

[PurpleHaZe]

anyone know the top end?

[polarsusd81]

Top end will be different for many based on a number of factors. Prop pitch, boat size, and loading will be the biggest of those factors. I would guess you will be somewhere around 25 or so on your own, and 21 with another person in the boat with you.

[Hula_Grub]

I have the same motor, just 2 years older. It is on a Lund 1425 Classic, almost 15' long. It is a relatively heavy boat for the size. Top end is 23 mph with just me, 21 with a partner, and about 19 with 3 of us with a 10x9 prop and 6000 rpm. I had both a 9.25x12 and a 10x11 prop and getting on plane was a problem with much weight in the back. The 10x9 prop fixed alot of problems. It trolls at idle at about 1.3 mph with just me. You might want a sandbag in the bow. When I went from a transom to a bow trolling motor it helped getting on plane.

I'm putting an SE sport 200 hydrofoil on it this year to help with load carrying as I want to take it camping in the BWCA and Voyageurs. The one time I took it camping I learned that I'd still needed to travel pretty light.

[Fishing Junky]

I had an '04 Lunker with a 25 fourstroke Yamaha on it. It also had tilt and trim, which helps get a little more speed out of it when your on plane or loaded down. Is your boat a tiller? Mine was, and what I did was raise the motor up a hole or two, and went with a stainless Turbo Hotshot prop. It was a 10 pitch prop, and was great. Boat got on plane decently and went pretty good considering it was only 25hp. This was at the time, my Sag boat in the bwca. It was a nice boat. Junky.....

[PurpleHaZe]

Its a tiller. i have 2 deep cells in front to hold the front end down, going to look at new elct. trolling motor. I would like to take one battery out and go to 12 volt to take some weight off the bow, its nice with just me but over weighted in waves with another person.

1.3 mph is a very nice speed. Is this with a special prop? will have to do some googleing when i get some time. thanks for the info. Still going crazy wanting to get out in lake. to here the little kitty purrr.

[Hula_Grub]

Just a composite piranha 10x9 prop. Mine's a tiller also. The only problem I've experienced is that there's no early power from the four stroke like there is from a two. I have to keep the weight and balance of the boat in pretty exact proportions or it can be hard to get on plane if I'm heavy.

I don't know what your boat weighs vs. mine, but if you have problems getting on plane I'd say to get a tach (google tiny-tach) and don't afraid to come down a step or two in prop size. Probably two steps if you're near the larger end. The tach will help you make sure you don't over rev.

With the first props I had and no bow-mount motor, I couldn't get on plane with the livewell full. I'm serious when I say COULDN'T. The livewell is side-mounted and aft. Also I had to inch forward out of my seat to get it on plane with the livewell empty. With someone else in the boat they had to move all the way forward to get it to plane.

The 9" pitch prop solved all of these problems. I'm not trying to scare you at all, I'm just trying to save you some of the experimentation and learning I went thru on my own.

Most of the lakes I fish are in the east metro- DeMontreville, Bald Eagle, White Bear, Keller chain,Big Marine. My average gas consumption was about a gallon per hour of motor usage. I used about 10 gallons on a week long trip to Kabetogama. I mainly fish for bass, so I'm not trolling all day.

[PurpleHaZe]

Hula grub

Thanks for the info about the prop i will for shure give the 10x9 a try right off the bat. Once again thanks for your imput.

[steffanf]

I have a 1425 Classic (SS) as well. You mentioned that it is a relatively heavy boat for it's size at just 14' 9"- it does have all the full flooring, storage, live well, etc. When I first bought it, it came with a 30 HP Merc Four-Stroke. The 30 is almost the exact same engine as the 25 HP model. The boat is a console model, but still, I could just barely get it up on plane with just me in the boat plus gear. It wouldn't even get close to plane with two people and NO gear. I went through the idea of possibly re-proping the engine with a different pitch prop, but I was told of the likelyhood of loosing alot of top-end speed. Since it already was slower than I would like with just one person, this option was not really acceptable to me. After confonting the dealer that I bought the boat from (he persuaded me that the 30 HP was more than enough power for this boat when I first bought it), I managed to get them to swap the 30 HP for a 40 HP- the boats' maximum HP rating. As someone mentioned here before, the difference is night and day. I can carry two people, alot of gear, cooler, 3 batteries, bow trolling motor and still get to around 30 mph.

Now, I know the W16 is a much lighter boat than the Classic series and you may likely be just fine with just the 25 HP. However, I learned the one rule that seems to be the standard: always get the most powerful motor your boat can allow. You will not regret it.

[Hula_Grub]

I learned the hard way, Steffan. The very hard way. If I knew then what I knew now I would have traded in for the 40 right away.

By going to the lower pitched prop I actually gained top end because I got so many more RPM out of the motor (about 750!). I was set on the 25hp because I wanted to have the motorized portion of the BWCA available to me.

[steffanf]

Sounds alot like the situation I was finding myself in, Hula. I was more angry that the salesman at the boat dealer didn't know what he was talking about. It actually seemed like NOBODY there knew much about my boat and recommended motor set-up... and they were selling it new! You didn't happen to buy your boat from a dealer in the Shokopee area, did you?

[Hula_Grub]

I got mine at a dealer a little north of the cities. I'm just as disappointed with Lund/Mercury for even suggesting that a 9.25 X 12 prop woud work on this boat and motor combo. The dealer, when I mentioned the problems I was having, seemed very surprised.

The nice thing about the piranha prop is that I can just switch out the blades for $15 each, so if I get the performance the hydrofoil promises, I might be able to go back to the higher pitch.

I broke my original prop the 4th time I had the boat out while trying to get on plane. It was the first time I had the livewell full.

Sorry about the thread creep...

[PurpleHaZe]

After doing some Serching i found a 10X9 composite parrana prop. My question is the one i found has 4 blades is this the one you tried Hula grub? thanks in advance

[Hula_Grub]

No- Mine's a 3 blade. Go to the piranha HSOforum for the correct blades and hub. I can't put it up here due to forum rules.

I'd also try the motor on your boat "as is" before assuming you have the same problems I or Steffan had. I just wanted to warn you ahead of time.

[Big R]

Thanks for reply. is crylsler the same as merc?

If they were - I would ask for a refund on your Merc.

[marine_man]

Most of the time smaller hp motors (under 40 or so) come from the manufacturer with a prop on it already. If a dealer doesn't water test the boat, or verify the prop pitch it's no wonder you ended up in the situation you found yourself in.

marine_man

[PurpleHaZe]

Hula Grub thanks for getting back to this topic. I wonder if you could send a e mail. of the prop you mentioned,my e-mail fishininmn at hotmail dot com thanks in advance

[marine_man]

That's fine if you e-mail, but to benefit everyone else, it would be great if the information stayed on this thread.

Thanks!

marine_man

[PurpleHaZe]

sorry i will for shure post it

[PurpleHaZe]

my boat weighs 450 pounds 16 foot lunker one small batt in back one big one in front transom trolling motor in back i have a livewell but dont use very often prefer stringer or cooler my prop on know is 9.5x11 never had it in water just bought it last Saturday i want a spare prop and will try 9x10 it seems pretty close to my 9.5X11 im all about supporting the right people so if any sponsers have a 9x 10 i will check that out

[marine_man]

One place to definitely check on a prop is Soderbloom's. Their prices are pretty competitive.

marine_man