Ford Jubilee Surging idle resulting in bucking

[2wheelgnnr]

Ford Jubilee....I sort think I know my problem but want to make sure nothing else. She bucks and idle surges up and down...like it running out of gas..sputtering and that....now to add to it I have had issues with the carb float sticking on me. I though I had if fixed but could this be a result of the carb float screwing up and not allowing proper gas flow to her.... may have to take it off again and clean up or something..........

again runs she running out gas spitting and sputtering along..........I think its a gas flow issue long and short of it......want to verify nothing else before I take carb off again........and take all apart........

Thank you guys.

Love my Jubilee.......put electronic points in it .......just need it to run properly ie smooth.

 

[used red MN]

Idle surging up and down is likely a passage or air jet in the carb is plugged. Will it rev up and go down the road in high gear? If so fuel flow is not your issue. Easy to check, get a pint container, pull the carb drain plug and wait 5 seconds then start catching the fuel. A pint in 2 and a half minutes would be adequate flow. If ran rich, spark plugs can get “rich fouled” with black carbon soot, have you checked them?

 

[2wheelgnnr]

Hmmmm yeah rev up and down...will go and sputter a LITTLE less in high gear across the lawn/down the road

She seems to be burning a lot of oil lately...or maybe too rich......I have not pulled the plugs I will do that tonight and see if they are all carboned up. if thats the case too rich.....which one is the air fuel mixture screw so I could turn the fuel delivery down a little.........so ok if Plugs all carboned up the sparking is semi intermittant or not strong due to build up.....ok.....

Hmmm air passage clogged...good thought as Ive had that thing apart and blew all out so maybe got debris in it...Good thoughts thanks..gives me things to check tonight. as I want to alot of work with her this weekend.

and actually yes Ive taken drain plug out to see if Im getting a constant flow and I am I was just thinking maybe not enough but what you says is about right as fuel flow goes...I guess im just so used to the fuel flow being the issue...this is a newer carb too......

 

[used red MN]

Hmmm air passage clogged...good thought as Ive had that thing apart and blew all out so maybe got debris in it...Good thoughts thanks..gives me things to check tonight.

My recommendation would be when cleaning a carb poke a wire through the passage the best you can. Then a squirt of carb cleaner and then blast of compressed air. THEN REPEAT THAT ON EACH PASSAGE!
I only said that about the plugs because you mentioned that you thought it was a float problem. Generally float problems are flooding problems which lead to rich mixtures which then foul the plugs. Reading and absorbing better it seems than you were thinking lack of fuel. Doesn’t matter, it is always good to mention other parts of the equation like spark plugs when hyper-focus is fixed on one thing like fuel.

 

[2wheelgnnr]

ok I will make sure this time I clean up the carb I do that. my float was sticking closed so I was not getting fuel and starving in my situation....... but a new carb fixed that. ( I would clean up float and in a couple months would happen again so just finally got new carb) but again........things can get in there........appreciate the responses... I will check all and see what happens...I have not and should look at plugs anyways...so.......ok

I guess since I had a starvation problem I always go back to that.......as it was in issue so often with the old carb.

 

[Jimmydog]

I'd check your intake manifold gasket for leaks. quick easy to eliminate that as a potential problem.

 

[casecollectorsc]

ok I will make sure this time I clean up the carb I do that. my float was sticking closed so I was not getting fuel and starving in my situation....... but a new carb fixed that. ( I would clean up float and in a couple months would happen again so just finally got new carb) but again........things can get in there........appreciate the responses... I will check all and see what happens...I have not and should look at plugs anyways...so.......ok

I guess since I had a starvation problem I always go back to that.......as it was in issue so often with the old carb.

Did you try opening the load needle a half turn to see if it helps?

 

[showcrop]

Since it is primarily an idle problem I would try richening the low speed a little by turning the screw IN a quarter turn.

 

[a49deere]

ok I will make sure this time I clean up the carb I do that. my float was sticking closed so I was not getting fuel and starving in my situation....... but a new carb fixed that. ( I would clean up float and in a couple months would happen again so just finally got new carb) but again........things can get in there........appreciate the responses... I will check all and see what happens...I have not and should look at plugs anyways...so.......ok

I guess since I had a starvation problem I always go back to that.......as it was in issue so often with the old carb.

You state you had problems with the "old" carburetor. You put a "new" carburetor on it and now you're having problems again? Sound to me like you may have a problem ahead of the carburetor, dirty tank, plugging up intake when gas is sloshing, or possible debris getting into carb. Have you done a compression test on it?

 

[2wheelgnnr]

ok now Ive screwed up the carb setting enough it wont start....is there a beginning settings for the air fuel mix screws like vw has.........like screw it all the way closed or till stops then screw out 2 1/2 turns..and start there.........I will play with more tonight and debris is always an issue...true...I will review that... I did take out plugs and appears running a bit rich...so try screwing the air fuel out a little to get a bit more air but now not starting at all.....will have to play with some more. Thanks all for the info.

I should do compression test and see where the rings are sitting.......

 

[2wheelgnnr]

help me identify these two adj. The thumb screw says the main adj. air / fuel?? but not sure what the second smaller screw it for. idle???

I found this for a starting point:
To properly set a Marvel Schebler stock carburetor, follow these guidelines:

Initial Adjustments

• Start with the idle speed screw and set it to a baseline position, usually around 1.5 turns out from fully seated.
• Adjust the idle mixture screw to achieve a smooth idle, typically around 1 to 2 turns out from fully seated.

Float Adjustment

• Ensure the float is set to the correct height to prevent flooding or starvation. This is crucial for optimal fuel delivery.

Fine Tuning

• Make small adjustments (1/8 to 1/4 turn) to the idle mixture and speed while the engine is warm, allowing time for the engine to stabilize after each adjustment.
• Monitor engine performance and adjust as necessary for smooth operation