brianbronc Posted August 23, 2022 Share Posted August 23, 2022 I have a 1986 F250 4x4, I6 300, gas truck. It has been running just fine and has since fallen off. Dropped rear tank, cleaned it out. Replaced all fuel lines, new gas pickup in tank and all new fuel filters. But still runs like timing is off and super rich. Adjusted timing slightly and seemed to make a big difference, but it is back to running bad. Added a 7psi electric fuel pump, thinking manual pump was not working correctly. Still issue. Which carb model is this? Is there a better carb to install? Link to comment Share on other sites More sharing options...
Gary Lewis Posted August 23, 2022 Share Posted August 23, 2022 That's the Carter YFA. The 300 is notorious for shaking the carb loose from its mounts. And the YFA can spring a leak in the accelerator pump causing it to run very rich. So my first check would be that the carb isn't ready to fall off, although that isn't likely to cause it to run rich. The accelerator pump is most likely the culprit. Link to comment Share on other sites More sharing options...
Gary Lewis Posted August 23, 2022 Share Posted August 23, 2022 Oops! I should have pointed out that you missed the email you were sent asking you to make your first post an introduction and put it in the New Members Start Here folder. We ask that because we keep the guidelines for the forum in that folder and want to ensure you've seen them. So before we talk about the carb any more please assure me that you've read the guidelines. And a post in the NMSH folder would be desirable so we can welcome you. Link to comment Share on other sites More sharing options...
mat in tn Posted August 24, 2022 Share Posted August 24, 2022 Oops! I should have pointed out that you missed the email you were sent asking you to make your first post an introduction and put it in the New Members Start Here folder. We ask that because we keep the guidelines for the forum in that folder and want to ensure you've seen them. So before we talk about the carb any more please assure me that you've read the guidelines. And a post in the NMSH folder would be desirable so we can welcome you. all in all it is a good carb. it is most likely needing a rebuild. if one degradable part has failed others are due to follow. it is the best for your truck unless you do a lot more work. Link to comment Share on other sites More sharing options...
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