My new project.1972 johnson 25e72r .

[Chrisham]

This motor ran 3 years ago.I used it a long time.When cleaning the carb 2 screws that hold the bottom bowl on were gone .Both on the same side.I have a 71 20 hp that is basically the same looks wise .I robbed 2 screws out of this bowl.The carbs looked the same.What is the difference The carb never leaked.Also what do you do about the packing for the needle it appears to be no longer available
I

 

[Crosbyman]

Iboats folks likely have parts or visit

https://www.marineengine.com/parts/johnson-evinrude-parts.php?year=1972&hp=25&model=25E72R&manufacturer=Johnson&section=CARBURETOR

 

[jimmbo]

It was well known in the late 60s and early 70s that the 25 hp used a different Carb, for more Airflow, than the one on the 18/20hp models. Marine Engine.com's website is not Correct.

Other differences were the Pistons, Crankshaft, Cylinder Head, and Intake Manifold. The Pistons used a different location for the Piston Pin, thereby changing the Port Timing, It also resulted in Lower Compression, which is why the Cylinder Head was different for the 25. and the Intake was slightly larger to help Breathing. Crankshaft was better balanced on the 25, because it was expected to run about 1000 rpm higher. Using a 25hp head on an 18/20hp motor will result is severe Detonation, likely destroying the Motor.

 

[Chrisham]

It was well known in the late 60s and early 70s that the 25 hp used a different Carb, for more Airflow, than the one on the 18/20hp models. Marine Engine.com's website is not Correct.

Other differences were the Pistons, Crankshaft, Cylinder Head, and Intake Manifold. The Pistons used a different location for the Piston Pin, thereby changing the Port Timing, It also resulted in Lower Compression, which is why the Cylinder Head was different for the 25. and the Intake was slightly larger to help Breathing. Crankshaft was better balanced on the 25, because it was expected to run about 1000 rpm higher. Using a 25hp head on an 18/20hp motor will result is severe Detonation, likely destroying the Motor.

Good to know I'll make sure I never swap those

 

[racerone]

The packing would now come in a carburetor repair kit !

 

[jimmbo]

I believe 1968 was the last year they used Packing and a Packing Nut to secure/seal the Idle Mixture Screw. In 1969, a Plastic Retainer, and what they referred to as a Bearing replaced the Packing and Packing Nut