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1993 Johnson 40

xpress2830

xpress2830

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Hey guys I am new here. I have a 1993 Johnson 40 J40EETB.15" Tiller. New top end 0.020 over, new pistons, bearings, seals, etc... I am running a 11 3/4 x 17 SST wheel. Bought the motor from Freshwater Outboards in Minnesota. Motor is like new. Had 50 carbs installed before motor shipped to me. The motor does not perform well at all. Does anyone know if the 40 48 50 powerheads are the same? I did see the reeds stops and carbs are different. I put 50 carbs 55D Highspeed jets, and 29 & 31 Low speed jets and the 50 reed stops. The heads have different p/n's so I ordered one off ebay. The 40 / 50 heads measure exactly the same. 20140930_155134_resized.jpgRetrievePhoto.jpg I do not see any performance differences to speek of. Any help would be greatly appreciated, Bobby...
 
Do you think this motor may perform better if I change the carbs back to the OEM 40 carbs and 40 reeds? What about maybe bumping compression up and open up exhaust tuner? Motor has 140 psi now !!!
 
Although the exhaust port timing may be different do you think 50 carbs, reed stops and open exhaust tuner would get me close to the 50 - 55 hp mark ??
 
In post # 1 you say " does not perform well at all " -----what does that mean ? ---What size of boat ? ---How heavy is the boat ?
 
I am running this motor on an Alweld 1548 marsh special, trolling motor, 1 battery, 6 gal fuel, jack plate 6" back, 3" above bottom of boat, 11 3/4 x 17 SST prop, with jut me boat runs 33mph trimmed out @ 5700 RPM. My uncle runs the same rig but 1648 console steer Evinrude 48 SPL runs 41MPH @ 6400 RPM same prop motor on transom...I am not wanting a race motor just as close to 50-55 hp as possible and stay reliable...
 
I would say 40mph is as good as youre gonna get with that motor & boat no matter how good it runs.. You may reach that with a 19 or 21 pitch prop. Youd have to experiment and see.. And its a tiller...You, Gas and battery are all in the very back. Weight distribution will never be optimal. I wouldnt want to go much faster that that in a tiller steer 15' aluminum anyway.
 
I have an 18 pitch Turbo Hot Shot prop ordered. I did move my battery up in the front ( bow ). I haven't run boat yet though. Thanks for the input, Bobby..
 
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