Jump to content

79 620 stalling itself out


NKC

Recommended Posts

I have a 79 620 and it’s having an issue where it sounds like it is starving itself of fuel and the choke flap is sometimes stiff and springy and other times it feels like it’s broken and just hangs there. I put sea foam all in the carburetor and the metal fuel lines and still has the same issue of stalling, any advice would be appreciated 

Link to comment
  • Replies 2
  • Created
  • Last Reply

Top Posters In This Topic

Top Posters In This Topic

Couldn't get the sound working. So....

 

 

Not much to go on. Start with....

 

Stalling while warming up? or after warmed up? or both?

 

When cold watch choke plate while someone steps on gas. You should see it close completely. 

Once started the engine should have a fast idle, does it?

When warmed up (10 min or so) choke plate should be fully open. Is it?

 

 

 

Link to comment

No sound. But from your description, this seems like two related issues. The first thing to check is the choke flap adjustment

13 hours ago, NKC said:

it sounds like it is starving itself of fuel and the choke flap is sometimes stiff and springy and other times it feels like it’s broken and just hangs there

 

Starving of fuel is running lean. It results in either engine stopping outright, or hesitation/bucking and maybe a cough up front (carb backfire)

 

The choke flap having no resistance to movement is a mechanical issue. If hanging halfway close, that will make it run lean when cold, and after engine warms up it results in too rich

 

To adjust the choke, wait for the engine to cool off overnight. Pump the gas halfway to set the choke. Then remove the air cleaner and look. Don't look at the choke marking (which is meaningless) but look at the choke flap. If it is not 100% closed, it needs adjustment. Rotate the round choke element until the choke just barely closes 100%. Verify that that when you move the choke flap by hand, that it "springs back" immediately to 100% closed. That's the complete adjustment. Then engine will then start right away and idle all by itself without stalling

 

Now then, after adjustment other problems occur may occur -- but you're one step closer to solving them. While you are testing, after the engine starts and is idling, view the fuel level in the sight-glass. It must be within 1mm of the line for perfect running

Edited by ggzilla
Corrected last sentence
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.