1648 alumacraft jon boat engine help

[boater1234]

Hello to all,i just upgraded from a 1436 to a brand new 1648 alumacraft jon boat.It's rated for up to a 35 but is light at only 310 lbs.I'm going to mod it out with wood and trolling motor,etc.... so i will add weight to it.The dealer i bought it from said i should keep the motor i have which is a brand new 20hp 4stroke tohatsu i originally was going to put on the 1436 but i just ran into a good chunk of money so i sold the 1436 and still have the motor.

My question is do you guys think i should keep the 20hp for the new boat or upgrade to a 25?The dealer thinks i should stay with the 20hp because he thinks being a lighter outboard the boat will perform better.The motor i'm looking into is a new 25hp 4stroke suzuki which is only 22lbs heavier then this tohatsu.Yes it's close to $1000 more but i have the money now and want to do this right the first time.I have a guy who wants to come buy my tohatsu for more then i paid for it because it's brand new never been used yet.The question is will i see that much more from the 25hp being a 3 cylinder and a extra 5hp compared to the 20hp or should i just stay with this 20hp.Like i said money is not a problem so if you guys think it's worth the upgrade please chime in.

I just don't want to spend the extra money if i'm only going to see like 1 to 2mph difference,that would be senseless.If i will gain like 5 or more mph and that extra torque then i believe it's worth the money.I'm weighing out the gas difference only because 22lbs is not much of a difference in weight.The zuki is only 136lbs and the tohatsu is 114lbs.I went to a boat show yesterday and most dealers said the 20 would do ok but the 25 would do much better and none of them were trying to sell me an outboard.Most of them just sold like the bigger end boats but there were a couple of smaller jon boats there.It was like 50/50,some said 20hp and some said go with the 25.So now i have a decision to make and i'm hoping someone with a similar package would chime in or any info would be great,thanks.

 

[gm280]

My opinion is you will not see much if anything in the top end speed between a 20 to a 25 HP engine. Now if you went to the recommended 35 HP engine then yes, but not a mere 5 HP difference... But that is just my opinion... See what others have to say.

 

[steelespike]

Go for more hp. You never see anyone saying I wish I had less hp. The 20 is only 21.4 cu. in. 2.15 gear ratio and a 9.2" X 9.8" prop.
The suz. 25 is 29 cu in. 2.09 gear ratio with a 10 1/4" x 11" standard prop.These specs indicate much better reserve power for adding additional weight.
The 25 has the ability to run at the 20s max speed and be loafing.
Any difference in fuel use will be tempered by the slightly faster speed and the ability to operate at the 20s speed at reduced throttle.

 

[boater1234]

I am going to run a 11 pitch on the tohatsu anyway but i see your point.I have had a 20hp 4stroke suzuki i ran a 11 pitch prop on and i got near 28mph with the 1436 i had and i loved it but was forced to sell the boat and motor due to money reasons.Then i ran into a little bit of money and was able to get a new 1436 alumacraft and a new 20hp tohatsu in the box for a steal of a deal,then i ended up running into a good chunk of money just a month later as of now and i sold the boat and i have a new 1648 on it's way to the dealer by march 4th.The other reason i don't really want to sell the tohatsu is as mentioned earlier i got the tohatsu for $2400 tax included and all with the 5yr warranty which is a unreal deal considering i just went to the boat show in tampa this weekend as it's still going on and the cheapest price i found one for was around 3k.I told them what i had paid and they didn't believe me but i have the paperwork so i know how good a deal it was.The suzuki is near $1000 more but i don't see how 5hp justifies that much more money.If i can get into the mid 20's which i believe i can running a 11 pitch prop that is good enough for me.

I can always upgrade in time if i want but i know tohatsu makes a great engine and i know they have allot of power.The 1648 only weighs like 100lbs more plus what i have been told in the past is the wider the planning surface of a jon boat usually the better it will run and near as fast as my smaller jon boat i had.I guess i will find out.I am just going to try out the tohatsu first as most of the time it will be just me or me and my friend.I have just watched a ton of videos on youtube with this size boat getting near the mid to upper 20's with this engine with no problem,then i saw some with like a 25 etec and it wasn't really that much faster at the top end,they were running near 30mph but like i said is it worth the extra $1000?That is what i need to consider and think about but all in all i think i may just keep the tohatsu at least for now.

 

[steelespike]

Makes sense,you have the motor see how it works out. more to follow.
By the way I checked some 25 Etec tests on 3 Aluma crafts.
1546,340#,2 men fuel test gear,12" prop,26.2 @5700. 13 mpg @ 5000.
1648, 380#,2 men fuel,test gear 12", 26.2 @5600.13.8 mpg at 5000.
V16 280#,2 men,fuel,test gear,battery, 31.6 @ 6000 16.8 mpg @ 4500.
I think the Jon is harder to push than a standard utility.
Probably the 5 keels jons usually have.
I do think that big flat bottom probably gets on plane easier.

 

[boater1234]

I just need to at least run it on my local lake,play around with it a little bit,adjust the tilt and see what kind of performance I can get out of her,I really hate to sell it for a 25hp if it's such a minimal difference,now I know I will definitely gain more power and some speed with a 25,no doubt about that. I just don't want to get the 25hp and be dissatisfied knowing I only gained so little for allot more $$$$. That is what's running around my brain. I just had a 20hp zuki a while back but was forced to sell and I have to tell you it was a little power house and it had some get up on my 1436. The 1648 only weighs 100lbs more then my original 1436 and the 1436 did 27-28mph with 2 people,gear with a 11 pitch prop,it was scary fast. I know this tohatsu will perform the same maybe better with a better gear ratio,I don't know. All I know is tohatsu makes awesome engines. I loved that Suzuki to. It was only 97lbs. All in all I just need to experiment with it. At the end of the day I do believe the tohatsu will be all I need though. I'm only doing back country fishing for reds,snook and trout so I'm not going out very far but a ways down the shoreline so as long as I get the mid 20s I'm happy. Nice to be able to get in fast with those nasty fl storms approaching in the summer.

 

[boater1234]

I found a 1652 lowe jon boat with a 20hp 4 stroke mercury on it. The boat is bigger,wider,and weighs 150lbs more then my 1648 and the guy posted his gps speed numbers. I am amazed. With 2 people and gear he got 27mph,with 3 people he got 24mph,with 4 people he got an amazing 21mph and he said it got on plane rather easy,those are some awesome numbers. I should be good to go with this 20hp on the 1648. I'm picking up the boat today and I'm pumped. I can't wait to get it on my local lake to test it out.

 

[boater1234]

Ok so i went a whole different route.I sold the tohatsu and bought a 25hp efi suzuki.I couldn't pass up the deal.I got it for $3100.I can't wait to get it on the water.Steelspike brought out a very good point.The suzuki is almost 500ccs compared to 351ccs on the tohatsu.I sold the tohatsu for $2400 and it only cost me $700 more for a whole different animal.This motor with a 13pitch prop should make my boat fly.I did a ton more research on this new 25 and it's a really sweet outboard and runs really quiet.The power is awesome.The biggest thing is it's only 136lbs which is only 22lbs more then the tohatsu and i can't wait to fire this thing up.Man i'm really excited.I figured we only live once and as most said you can never have to much power but we can always not have enough.I figured i know it's still under the max rating of 35hp and if i want to take more people out in time it will never be an issue.I found a lone new 25hp 2 stroke yamaha a dealer had here in fl but they wanted near 4k for it and i know yamaha's are bulletproof but i got a 6yr warranty with this suzuki and a $200 rebate on top of it to boot.I think i made the wise choice by saving near $900 not getting the yamaha.