Envinrude 4425

[JohnInOhio]

I've searched the forums and found quite a few old posts on 4425's, mostly trying to figure out the year of manufacture. My 4425 (serial #00158) is in pretty decent shape, and runs great. The only issue is that the original knob on front was replaced with what is probably an old TV knob, and has no connection to the choke linkage. I'm looking for information, and/or pictures to show how the knob is supposed to close/open choke when turned. Hopefully someone out here can help me out.

Thanks
John

 

[F_R]

Your model and serial number equate to a 1948 Sportsman 1.5hp

 

[JohnInOhio]

Although I'm not too concerned about the mfg date, thanks anyway. I'm really after details of the choke linkage to the carb adjustment knob. I have detailed assembly drawings, but they don't show anything on the carb.

 

[racerone]

Visit----aomci------Lots of willing helpers there.

 

[JohnInOhio]

Visit----aomci------Lots of willing helpers there.

Been there. So far, no help.

 

[oldboat1]

sure you are not confusing the choke with the air mixture adjustment? Maybe a pic....

 

[JohnInOhio]

sure you are not confusing the choke with the air mixture adjustment? Maybe a pic....

The "carb adjusting knob", as referred to in the instructions, is no doubt the same as air mixture. On the left side of the carb, the end of the choke butterfly shaft sticks out with the little lever on it. The following is copied from a Sportsman pdf file, "For carburetion, the Sportsman used a float-feed Tillotson MD11A carburetor with a spring-loaded choke butterfly". On this motor, there is a wire (see blue wire lower left) attached to that lever so that you can pull the choke manually. It seems logical that when you move the adjusting knob to the "choke" position, it somehow is linked to the butterfly lever to choke, then release as the knob is turned clockwise to run and "tune" the mixture. I've attached a pic of the instruction details and current carb adjusting knob. thanks

 

[F_R]

This is the best picture I have, but is not very easy to make out when enlarged any more. If it isn't clear enough let me know and I'll doctor it up a bit. Anyhoo, the choke link is held in position at the bottom end by a guide. A tang on the backside of the knob (not shown) engages the link and pulls it down when the knob is turned all the way to the left.

Frank, member AOMCI

 

[F_R]

A similar knob but for a different model motor. This one does not have the choke tang on the backside.

 

[JohnInOhio]

This is the best picture I have, but is not very easy to make out when enlarged any more. If it isn't clear enough let me know and I'll doctor it up a bit. Anyhoo, the choke link is held in position at the bottom end by a guide. A tang on the backside of the knob (not shown) engages the link and pulls it down when the knob is turned all the way to the left.

Frank, member AOMCI

So it looks like I could need several parts. The guide-choke link, choke detent spring, and choke shutter return spring. Also, a picture of the tang at the back of the knob. I'm assuming I'll never find an original knob, so I would have to try to fabricate one. A picture is a must. I'd like to re-create as close to what it should be. thanks. Maybe send the carb jpg in a message to me? It may be cleaner that way.

 

[JohnInOhio]

This is the view I need of one that has the guide, knob w/tang, etc.. My choke has the return spring which seems to work fine.

 

[JohnInOhio]

I'm guessing that the choke is similar to throttle as far as linkage. The speed adjustment lever just pushes against the throttle to increase speed or decrease. The choke tang probably makes contact near the guide to close butterfly, then when knob is turned clockwise, the choke returns to open via spring. I may be totally off!

 

[F_R]

Try this re-scan. Believe it or not, a competing parts place which I cannot mention here has the 551686 link in stock. Call iboats' OEM parts dept and see if they can help you on this.

 

[JohnInOhio]

Thanks. I'm still holding out for someone to get me some photos of one that's original. Maybe I'll get lucky!