Jump to content

Electric choke not choking completly


enbay1

Recommended Posts

Hello,

I've got an issue causing hard cold starts. I don't think my choke is engaging all the way. If I manually choke it while starting it (using two people, or a stick, or something) it always starts right up. The fast idle cam works, but maybe the spring on the fast idle cam doesn't seem strong enough to move the choke back up after sitting for a while. The choke does disengage all the way after warming up.

Here's a video of the choke going from open to closed when the throttle is goosed, and what the free-play looks like.

As always, thank you for your time.

 

Video.

  • Like 1
Link to comment
  • Replies 10
  • Created
  • Last Reply

Top Posters In This Topic

Top Posters In This Topic

Depends on the year but earlier ones had 3 screws around the outer black plastic housing. Loosen and turn counter clockwise to set richer.

 

 

The later 720s the choke was set and not adjustable. I think this one below was sealed. But...
 
3amNNxv.jpg

 

 

There was a tab that locked the black plastic choke housing from turning. I just ground the tab away and made it adjustable....

D6n1Tll.jpg

  • Like 1
Link to comment

The choke is controlled solely by a bi-metallic spring under that black cover. When cold it contracts and will pull the choke plate closed. There is an electric heater under it that warms the spring when the engine is running and it unwinds opening the choke. The fast idle cam is pulled up into position by a linkage connected to the choke plate. When the choke opens the fast idle cam is free to drop down out of the way by it's own weight.

 

The electric heater is timed (about 8 min) to open the choke as fast as the engine warms up. It's efficient, fool proof and saves gas over the manual type.

  • Like 1
Link to comment

The 'spring is mounted inside that black cover. It has a hook shape that has to be hooked over the choke plate arm as it is put in place, then turned left or right to set the amount.

 

RLg5TcI.jpg

 

If the choke is the kind that can't be adjusted you will find a small obstruction on the case. Just grind it away so the cover can be turned.

  • Like 1
Link to comment

I took out the two rivets and the phillips screw on the bottom, filed off the tab, and adjusted the choke. The inside of the spring housing was filled with what I can only describe as carbon deposits. Black, crusty, horrible stuff.

 

I had previously cleaned and lubed everything THOROUGHLY.

 

Based on one start-warmup cycle I can say the choke works now!

  • Like 1
Link to comment

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
×
×
  • Create New...

Important Information

By using this site, you agree to our Terms of Use.