Im from sweden so I reserv myself if the text dosnt make sense or if i have too clearify anything later on.
As the title says I have an Johnson 70 hp two stroke from 2001 that has started too loose its power on idle and slow trolling speed. When i started the engine up on land the other day it all seemed fine and dandy but when i put the boat in water the engine worked fine for about 10-15 min then t just died at slow speed. It started right back up and worked for another 10-15 min then the same thing happened again.
It died pretty fast from 2000 rpm to 0 in a second and starts right back up and works fine for a bit. After hecking the fuel hose from my tank to the engine and reattached it and pumped in new fuel too the enginge it worked pretty well on the way back. It didnt die on the way back but instead it lost power so I had too give it more accelaration for the engine too not die. Then after a minute or two the engine almost "woke up" and keept accelerating so then i had too decrease the speed and later on increase it again, and that what i had too do all the way home.
So I feel like its the fuelpump or mabey the carbuetor that is the problem.
https://www.youtube.com/watch?v=QBpaXYZVMWg a short video at around 0.25 you can hear how the engine dips down and at 0.39 the engine almost dies completly.
Hope for some advice and have a good summer with lots of fun on the lake you all!
In the video it almost sounds like it is missing on a cylinder. It may have more than one problem.
If you plan to work on it yourself, obtain a factory service manual first You can get one from www.outboardbooks.com
Check fuel pressure, compression, carburetors, and make sure the ignition system is strong enough to jump a 7/16" gap at cranking speed.
If it has been unused for a while, stale fuel deposits may be affecting the carburetors.
"There is never just one thing wrong with a boat";
-- Travis McGee, main character in a book series by John D. McDonald
The factory recommends that a properly trained technician service your Johnson or Evinrude outboard motor. Should you elect to perform repairs yourself, use caution, common sense, and observe safety procedures in the vicinity of flammable liquids, around moving parts, near high-temperature components, and working with electrical or ignition systems.
The information offered here is only general in nature and should not be construed as complete factory approved procedures, techniques, or specifications. Always use the proper service manual for your motor, up-to-date service literature, the correct tools, and have an understanding of how to proceed with troubleshooting and repair methods. If you are unsure or uncomfortable with a procedure, a situation, or a technique, enlist the services of a factory trained technician.