1976 Johnson 15 hp

This may have been discussed or maybe not. I am new to the board so here we go. I own a Tracker Guide V 14 riveted weights 235lbs, Plus a battery trolling motor, 65lbs of flooring and me 210 lbs. I have lync and sync my carb after rebuild new points gaped .20 new condensers new plugs gaped a .30 rebuilt fuel pump. She planes my boat no problem Idles real good no issues except I am averaging 15 to 17 mph prop is a 9 1/2-10. I raised the motor so my cavitation plate is even with the bottm of the boat. It is tilted 2 holes up past dead flat on the transom I have 110 psi both cylinders. Why aint I getting more speed then 15 to 17 mph. Is the motor to small. The boats rated for 25. Now before anybody tells me a bigger motor. I have been on utube and have seen 15 hp pull skiers from a john boat what gives....Thanks Skully

What is your motor RPM at WOT?

JMichael said:

What is your motor RPM at WOT?

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I am totally un aware of how to tach it so I dont know if i could tach it I would unless you have a answer on how to tach it...

Skully said:

JMichael said:

What is your motor RPM at WOT?

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I am totally un aware of how to tach it so I dont know if i could tach it I would unless you have a answer on how to tach it...

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I know that rpm is key and they run wot throttle at I believe 5500 no way of knowing

Skully said:

Skully said:

JMichael said:

What is your motor RPM at WOT?

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I am totally un aware of how to tach it so I dont know if i could tach it I would unless you have a answer on how to tach it...

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I know that rpm is key and they run wot throttle at I believe 5500 no way of knowing

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Sounds to me that you kinda agree that I should be getting more MPH at of it. Im gonna do some research as to how to install a tach I believe your on to something here JMicheal

You would need a tach in order to find out what the rpm is. One like this or similar would do the job.
https://www.americanparagliding.com/tinytach.htm

If the motor has the wrong prop on it, it could affect how fast it gets on plane, top speed, etc.

My brother has a 14ft with 18hp motor and with 500lbs of weight in the boat it will make 21mph. So even though I'm not 100% sure what you should expect out of your boat/motor, I would think it would go faster than that with so little weight in the boat.

JMichael said:

You would need a tach in order to find out what the rpm is. One like this or similar would do the job.
https://www.americanparagliding.com/tinytach.htm

If the motor has the wrong prop on it, it could affect how fast it gets on plane, top speed, etc.

My brother has a 14ft with 18hp motor and with 500lbs of weight in the boat it will make 21mph. So even though I'm not 100% sure what you should expect out of your boat/motor, I would think it would go faster than that with so little weight in the boat.

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Thats what I am guessing as well Thanks for the help

im guessing your already at 5500 rpms, with that boat and the weights you posted i doubt your gonna get any more speed out of it. 17mph is pretty quick for that set up. are you using gps to get your speed reading?

shawnfish said:

im guessing your already at 5500 rpms, with that boat and the weights you posted i doubt your gonna get any more speed out of it. 17mph is pretty quick for that set up. are you using gps to get your speed reading?

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Yea I'm using gps and when I am in my vehicle its read about 3 mph slower then my vehicle tach so. I'm assuming 17 mph adding the 3 more mph to the 13 and and 14 I'm getting on the water. I guess eventually I will see if I can upgrade to a 20 or 25 hp gotta be a johnson or evinrude of the 1970's era pre electronic ignition too costly to replace electronics and the older motors are easier to tweek and are bullet proof can I get an amen! My brothers! Dont care much for Mercs or the other stuff ol school johnson-rude. I know I know some merc guys may take offence to my statement and have valid points! Wait did I say points... no pund intended....To each his own success story..Just sayin

AMEN!!!!! johnny/rude all the way!! dont limit yourself to the 70's though, the 25's are bulletproof and built like brick s#**houses through the 80's too!! very very good motors!!! havent seen too many or had much experience with them beyond the 80's so i dont know, but pre 90's 25hp and under are the most reliable well built user freindly motors ever built IMO.......

shawnfish said:

AMEN!!!!! johnny/rude all the way!! dont limit yourself to the 70's though, the 25's are bulletproof and built like brick s#**houses through the 80's too!! very very good motors!!! havent seen too many or had much experience with them beyond the 80's so i dont know, but pre 90's 25hp and under are the most reliable well built user freindly motors ever built IMO.......

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I will keep your experience with them years in mind thanks.

Skully said:

shawnfish said:

AMEN!!!!! johnny/rude all the way!! dont limit yourself to the 70's though, the 25's are bulletproof and built like brick s#**houses through the 80's too!! very very good motors!!! havent seen too many or had much experience with them beyond the 80's so i dont know, but pre 90's 25hp and under are the most reliable well built user freindly motors ever built IMO.......

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I will keep your experience with them years in mind thanks.

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your welcome, this forum confirms my experience with them. look how many threads in this section are evinrude/johnson related, now some people(and ive never met one) may think thats because they are not good motors and they are broke all the time and they would be dead wrong. now what that tells me is that there are more evinrude/johnsons still running that were built over the last 60 years is that they are by far better than any other OB manufacturer hands down......that being said, im not saying every other brand of OB's out there are junk its just that you cant compare johnny/rudes to any other for reliability.but thats just my opinion......

I'm of the opinion that the GPS would be more accurate than a vehicle tach or speedometer.
And yeah those older Rudes and Johnnys are hard to beat. Reminds me of an old Ford tractor, they just run forever. :LOL2:

Charger25 said:

I'm of the opinion that the GPS would be more accurate than a vehicle tach or speedometer.
And yeah those older Rudes and Johnnys are hard to beat. Reminds me of an old Ford tractor, they just run forever. :LOL2:

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Yep, my money would be on the GPS as to which one is accurate. As far as motors go, it's just like cars/trucks, everybody has their own experiences and their own favorites.

JMichael said:

Charger25 said:

I'm of the opinion that the GPS would be more accurate than a vehicle tach or speedometer.
And yeah those older Rudes and Johnnys are hard to beat. Reminds me of an old Ford tractor, they just run forever. :LOL2:

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Yep, my money would be on the GPS as to which one is accurate. As far as motors go, it's just like cars/trucks, everybody has their own experiences and their own favorites.

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I agree if you find Merc does you good and has over years so be it. Its kinda like the Ford Chevy thing only johnny-rude being the chevy and merc being the ford. If ya know what I mean...

Hows ur boat loaded? What cond is the prop? like others have said maybe ur not getting full rpms, whats the stock prop reccomendation? Have you tried different pin locations on the motor transom. I would have to say 15 mph may be a bit slow, 17-20 mph should be about what your set -up should run . So your in the ball park. Now a 20-25 hp will make your boat fly. My 14ft deep V with a `69 - 20hp with 3 adults will hit about 25 mph and comes up on plane in an instant.