Conversion 1998 25Hp Johnson

[arkansasbowhunter]

Hello,

I am new to the site. I recently purchased a new 1999 Johnson electric start motor. Unbeatable deal in that the owner never ran it. Anyways, I am interested in finding out if I can upgrade the motor to a 30 or 35 hp with modifications. I have converted an older 9.9 johnson to a 15 by doing the carb work on it but have no idea on this motor. thanks for looking and any help.

 

[wilde1j]

Re: Conversion 1998 25Hp Johnson

Why didn't you just buy a bigger motor?

 

[CATransplant]

Re: Conversion 1998 25Hp Johnson

I don't know. Why not run it as it is for a while and see how it performs on your boat. What kind of boat do you have, and what's the max hp listed on the transom tag?

 

[restornator]

Re: Conversion 1998 25Hp Johnson

the 35hp was a 3 cylinder that year. There was a detuned 25hp 3 cylinder as well.

There was also a 20 25 and 30hp 2 cylinder line. With a 30hp jet drive labeled as 28hp, and a 20hp jet drive labeled as an 18. Carbs and intake mainfolds were the primary difference. the 20's and 25's had the same intakes and carbs for the most part

 

[CATransplant]

Re: Conversion 1998 25Hp Johnson

Sounds like we need a model number to make sense of this question...

 

[ondarvr]

Re: Conversion 1998 25Hp Johnson

the 35hp was a 3 cylinder that year. There was a detuned 25hp 3 cylinder as well.

There was also a 20 25 and 30hp 2 cylinder line. With a 30hp jet drive labeled as 28hp, and a 20hp jet drive labeled as an 18. Carbs and intake mainfolds were the primary difference. the 20's and 25's had the same intakes and carbs for the most part

There's about a 30% reduction in HP with a jet, so the 2HP reduction you note doesn't look right. A 30 would be around 20.

They did start to uprate the advertised HP on some jet models though, the 90/60 was labeled a 90/65, no changes other than in print. Looks good to market the HP 5 higher than the competition and it costs nothing to do.

 

[arkansasbowhunter]

Re: Conversion 1998 25Hp Johnson

well I didn't buy a bigger motor because it was a package deal. I have a guy at work who's wife bought him this boat, motor, trailor, combo fully rigged out for xmas that year to duck hunt out of and fish. The man never took it out of the garage. the rig is new and never been in the water. I had to knock the spider webs off it and wash it down. This boat is new just a 1999 model and never had a tank of gas ran through it. It is a 1542 war eagle boat. Hope that answered some questions. This was a diamond for sure. With this years same set up it would run 10k and I picked it up for 3500. I put a new battery in and the motor fired right up. Tires still have original sticker on tread LOL. Any ways, I was fishing with it and had 2 other big guys in the boat and the boat dropped way down in top end when loaded down. I do hunt with it and so thought the extra hp would be great when loaded down. The motor is not a jet drive but prop driven. All my friends want to buy the boat but I think I am gonna keep it.

The model number is J25TEEEE serial #G04533219. Thanks for help.

 

[tashasdaddy]

Re: Conversion 1998 25Hp Johnson

screwing with this, is a good way to ruin a good motor.

 

[ondarvr]

Re: Conversion 1998 25Hp Johnson

I don't think he meant you had a jet, just that there were several option for motors in that time frame.

The normal answer is to sell the motor you have and get a bigger one and it applies in this case too. Its typically easier and costs less.

 

[wilde1j]

Re: Conversion 1998 25Hp Johnson

I would sell the 25HP and buy a bigger motor. Way less hassle.

 

[restornator]

Re: Conversion 1998 25Hp Johnson

I would sell the 25HP and buy a bigger motor. Way less hassle.

i was about to say, you can sell that motor and get a 35 without spending any extra money

 

[arkansasbowhunter]

Re: Conversion 1998 25Hp Johnson

don't quite understand why you say screwing with it would mess it up. The 9.9 to 15 conversion was just a carb exchange as they were basically the same motors. It was my understanding that the 25 and 35 was the same except for carb and linkage also.

 

[blimp]

Re: Conversion 1998 25Hp Johnson

I believe you can just get a throttle plate and carb from a 30hp, but its worth doing all the part# searching between the two. I have done the same with an '85 Evinrude, but I'm sure a lot can change in 14 years...

http://www.boats.net/parts/search/BRP/JOHNSON/1999/J25TEEEE 1999/parts.html

vs

http://www.boats.net/parts/search/BRP/JOHNSON/1999/J30EEEN 1999/parts.html


war eagle....nice.

 

[CATransplant]

Re: Conversion 1998 25Hp Johnson

well I didn't buy a bigger motor because it was a package deal. I have a guy at work who's wife bought him this boat, motor, trailor, combo fully rigged out for xmas that year to duck hunt out of and fish. The man never took it out of the garage. the rig is new and never been in the water. I had to knock the spider webs off it and wash it down. This boat is new just a 1999 model and never had a tank of gas ran through it. It is a 1542 war eagle boat. Hope that answered some questions. This was a diamond for sure. With this years same set up it would run 10k and I picked it up for 3500. I put a new battery in and the motor fired right up. Tires still have original sticker on tread LOL. Any ways, I was fishing with it and had 2 other big guys in the boat and the boat dropped way down in top end when loaded down. I do hunt with it and so thought the extra hp would be great when loaded down. The motor is not a jet drive but prop driven. All my friends want to buy the boat but I think I am gonna keep it.

The model number is J25TEEEE serial #G04533219. Thanks for help.

That boat is rated for 25hp max. Trust me...it will perform just fine with the 25hp. Increasing the horsepower will exceed the ratings for the boat and be dangerous. I'd just stick with what you have and go fishing.