25 or 30 HP 4 stroke vs. 40 HP 2 Stroke

WIll James

Recruit
Joined
May 5, 2004
Messages
4
Which john boat motor has been manufactured for the longest period of time that has proven to be the most reliable, failsafe engine on the market? In addition to this question, I have inherited a 17' SeaArk john boat that has a 1986 40 HP Johnson that has had its share of abuse, and I have been stranded with it one too many times. The Johnson 40 was plenty of power and plained the boat out nicely even loaded down. I would think purchasing a smaller 4 stroke engine due to weight and lower end torque advantages will work, but have not been around enough boat motors since high school to know. Will a 25 or 30 run the boat as fast as the 40, and which brand/model/HP is my best option? It seems most manfacturers produce more 25's than 30's. Thanks for the help.
 

cobra 3.0

Lieutenant Commander
Joined
Jul 31, 2003
Messages
1,797
Re: 25 or 30 HP 4 stroke vs. 40 HP 2 Stroke

No Way! Two strokes out-perform four strokes any day! There is continuous work being do to try and approach the perfomance of the two stroke. <br /><br />Four strokes really shine for low noise, low or non existant smell/fumes, and very smooth and quiet trolling/idling. However, weight and size is significantly more.
 

Forktail

Ensign
Joined
Feb 11, 2002
Messages
977
Re: 25 or 30 HP 4 stroke vs. 40 HP 2 Stroke

Thunderbolt, the "best" outboard is a matter of opinion, and can be based on many things. I use outboards commercially in some tough environments, and from my experiences Yamaha does it "best". :) <br /><br />Your 17' Sea Ark is probably rated somewhere around 40 HP max. A 30 would be fine, especially considering your description of the current 40's performance.<br /><br />You may not need a smaller HP outboard to make up for the weight and torque of a 4-stroke. I'm not sure what the 40 HP Johnson you have now weighs, but for example a current model Johnson 40 HP 2-stroke weighs 195 lbs. The 4-stroke Honda BF40 and and the 4-stroke Yamaha F40 weigh 198 lbs. So only a few pounds difference. The Honda BF30 weighs an amazingly low 152 lbs. So weight and size are very comparable.<br /><br />"Performance" is something you have to define. Is it speed, acceleration, economy, durability, logevity, etc.? Either way, I've never seen a 2-stroke with overall better performance than a 4-stroke. They'll both get you on step with a load, and both give you good top speed. But IMO, the 4-stroke will do it with more enjoyment. :)
 

JB

Honorary Moderator Emeritus
Joined
Mar 25, 2001
Messages
45,907
Re: 25 or 30 HP 4 stroke vs. 40 HP 2 Stroke

I agree with Forktail on this one, Thunderbolt.<br /><br />Cobra's comment about performance is simply a Ford/Chebby loyalty statement.<br /><br />I am really sold on EFI in 4 strokes, so I would be looking at the Bombuki and Merc EFI 40s, but your priorities may not be the same as mine.<br /><br />Good luck. :)
 

cobra 3.0

Lieutenant Commander
Joined
Jul 31, 2003
Messages
1,797
Re: 25 or 30 HP 4 stroke vs. 40 HP 2 Stroke

Sorry, I suppose I did come off ford/chebby in my statement. :D However, he is asking if a 25 or 30 four stroke will perform like a two stroke 40. You boys saying that it will? "Performance" to me is acceleration and top end speed(since he mentionned 'fast'). Will the lower end torque of the four stroke 25 to 30 hp compensate for this? I have a hard time believing that.
 

JB

Honorary Moderator Emeritus
Joined
Mar 25, 2001
Messages
45,907
Re: 25 or 30 HP 4 stroke vs. 40 HP 2 Stroke

Just about any 40hp engine will be quicker and faster than just about any 25-30 hp engine, but it will also use more fuel and often weigh more. That weight can affect the handling of some boats.
 

Jdeagro

iboats.com Partner
Joined
Jul 30, 2003
Messages
1,682
Re: 25 or 30 HP 4 stroke vs. 40 HP 2 Stroke

I hate to see a decision made simply because of the extra weight. The balance of the boat is most certainly a factor, however this can be corrected in other ways. With regard to “performance” the standards are usually based on acceleration and top speed, which in MHO is very limiting. That being said, anything which restricts the boat from attaining top speed (not respective of the motor HP and Torque) will restrict the performance throughout the entire operational cycle. <br /><br />The four stroke motors build to maximum HP and Torque at lower RPMs than a two cycle. Hence the better fuel economy. Low end torque builds slower so they are not noted to be fast out of the gate. They cost more, but they are quite. Maintenance may be higher, but they may last longer before a rebuild. In essence there are two sides to every coin. You pick the side that you like for your use.
 

WIll James

Recruit
Joined
May 5, 2004
Messages
4
Re: 25 or 30 HP 4 stroke vs. 40 HP 2 Stroke

Keep in mind too this Johnson 40 is 18 years old, was abused for about 8-10 years, sat idle for 4-5 years and put back into use 2-3 years ago. The engine today probably doesn't perform like it should. It sure doesn't start like it should and doesn't idle/troll very well either. Once the engine RPM's get up the engine sounds alright. Its been tuned up at least twice, and I don't want to completely rebuild the engine. Plus I want an electric start. Since the boat and trailer where free to me, I think its time to replace the motor. After looking at SeaArk's website, a 30 HP should do it (they rate a slightly wider & deeper boat with a 35). Next question is make and model. Any thoughts? Boat use will be infrequent coastal creeks pleasure/touring some fishing/duck hunting. Appreciate the feedback.
 

phatmanmike

Captain
Joined
Oct 24, 2003
Messages
3,869
Re: 25 or 30 HP 4 stroke vs. 40 HP 2 Stroke

thunderbolt, if you replace that beast , can i come get it? im close <br />phatmanmike@yahoo.com<br /><br />nauti john seems to be the sane one of the group...there are two sides to every coin, there is no "perfect" outboard. same make more power, but are louder, some are cleaner , but are more expensive. some like it hot... some like it hot(sorry i just had to)<br /><br /><br />as for what type of motor for your boat... thats depends on a lot. it depends on how much of the work you can do yourself or how far you wanna drive to a dealer for repairs and parts.mercurys, evinrude/johnsons seem to be the two main dealers supported motors round here, probably every where else in america too. yamaha is the most supported of the japanese motors and a damn fine one at that.every manufacturer now makes a 2 and 4 strokes for the size you need(honda makes just a 4)<br /><br />in my personall opinion, nothing screams"balls" like a maxed out 5800 rpm 2stroke flying by ya at 40mph...hehehe :)
 
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