Here is some guidance that will help you evaluate your motor and help us help you!
Now you want to use a systematic approach to assess your engine's problem. Sure, it maybe just needing a carb kit and cleaning and your on your way. But if you a systematic approach to evaluating a motor then you become more efficient than you just guessing and changing out parts.
You will see a lot of experience guys ask about compression, spark and fuel. (They are using a systematic approach to diagnosing an engine problem or problems....in this order)
C= compression ( if your compression is low are uneven between cylinders >10% then others checks don't matter until the that is resolved) Low compression will cause your motor not run or run very poorly.
S= Spark (if your have problems with your ignition then you can have the cleanest carb and great fuel delivery but it will run bad or not at all)
F= Fuel (if your carbs are not clean and fast/slow idle needle are not set right then it will run but like crap. If you have it set too lean then you run the risk of poor fuel/oil delivery and damage your pistons and cylinders then you run into the problem of C (poor compression from damage).
For your motor to run and run well (this a general statement) all three of above categories need to be fulfilled.
So it is advisable to get a manual for your motor. Excellent resource, specifications, and diagrams.
How to check compression: (remember to remove both spark plugs) You can get a compression guage for about $10 to 12 dollar at harbor freight or auto zone) auto zone will let you borrow one with a refundable deposit)
https://forums.iboats.com/showthread.php?t=391323
https://www.youtube.com/watch?v=PyCw4SiuT2I
(gives you visual)
How to check for spark.(with a spark checker) about $6 at autozone (or similar store)...harbor freight store. You will also need a feeler guage to gap your spark plugs to 0.030 (feeler gauge is about $3 to 4 dollars)
- adjust the spark test to about 5/16 inches or so. It should be a good strong blue spark. (don't forget to ground the tester to the motor) When some just grounds the spark plug to the motor and see there is a spark and call it good....that not enough. You want to access the quality of the spark.
The quality of the spark tells you the health of the ignition system. A spark that can not make a jump of 1/4 to 5/16 on the spark tester is indicating problems.
-could be pitted or fouled points
-could be a cracked coil that is still somewhat functional but not dependable.
-etc
https://forums.iboats.com/showthread.php?t=294072
https://www.youtube.com/watch?v=lk70oyUEftY
(general visual)
Carburetor adjustments
https://forums.iboats.com/showthread.php?t=167352
Carburetor cleaning instructions
https://forums.iboats.com/showthread.php?t=244013
Check to make sure the vent cap or plug on the tank is open. If it is not open then the motor will run ok for a little bit and die or run poorly. The vent cap or plug has to be open to allow air to enter the tank so fuel can easily be pumped out of the tank by the fuel pump. If the vent cap or plug is closed then the fuel pump has to work against a negative system created in the tank, and you may get low or no flow from the tank.**** Make a long story short, make sure the vent cap/plug is open and try to start your motor.
Also check to see if the fuel line bulb near the tank has the arrow pointing toward the motor and pumps up somewhat firm.
Here is a electronic parts diagram of your motor, so that will help you a bit.
https://www.marineengine.com/parts/...ntage-evinrude-johnson/381415/38141500001.htm
So, some homework
Get some compression numbers and check your spark with a tester and report back with your finding and a seasoned and experience member can assist you better. (Be sure to have your motor in water to run, if not you run the risk of damaging the water pump and not cooling the powerhead and burning it up.)
Proper fuel to oil ratio is 50:1
8oz TCW-3 oil with 3 gallons of gas(87 octane)....mixed well.