67 3hp evinrude screen air silencer

[hdman97]

Do you really need part# 203320 screen air silencer?
Searched all over,thought it might make a difference in performance.
Thanks

 

[boobie]

Re: 67 3hp evinrude screen air silencer

No, but the mtr will be more quiet with it on.

 

[hdman97]

Re: 67 3hp evinrude screen air silencer

Just wanted to update this as to hopefully help anyone else that may search on this.
I didn't have the silencer on this engine so I made one.
This made an huge inprovement on the high speed of the engine.
I think it may be because the carb on this motor (1967) has a fixed high speed jet.
Some of the older 3hp engines don't.
The engine stumbled and boged down when going from slow to fast.
Must have sucked in too much air without the silencer.

 

[F_R]

Re: 67 3hp evinrude screen air silencer

Your obversations are valid. I'm surprised your home-made silencer works. You are either lucky or good at what you do.

 

[Chinewalker]

Re: 67 3hp evinrude screen air silencer

The screen between the silencer and carb body must be there. It essentially keeps the motor in a partial choke condition, which they deemed necessary due to the small crankcase volume unable to properly suck fuel through the carb - or so I was told by a long-time Johnrude mech. Makes sense to me as the 3s I've had do run better with them in place. They must have fixed the issue when they upgraded the 3 to a 4 in 1969 as the 4s did not have the screen - or the horn for that matter...

 

[hdman97]

Re: 67 3hp evinrude screen air silencer

Your obversations are valid. I'm surprised your home-made silencer works. You are either lucky or good at what you do.

Thanks,but I didn't make the whole silencer just the screen .
Could not find one anywhere.That's what was missing.