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Stock Carb Bog


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My 78 DL project is coming along.  Last night I was able to fix the transmission shifting issues by installing a new governor gear.  It shifts great now; however, when you try to make the car take off there is a significant bog and the engine nearly dies.   In order to get the car underway you need to baby the throttle.   It starts right up and idols strong, but there is definitely something wrong with how it is currently tuned. 

 

Since its cold it might be running lean, and it is from Colorado which is several thousand ft. higher in altitude then Kansas City.   However, I don't know how to tune a stock carb.  My Brat has the webber swap.   Can anyone point me to some tuning articles or describe how to adjust the stock carb. 

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sounds like the accelerator pump is bad or your timing advance diaphragm on the distributor may be bad. if you pop the distributor cap off you can see the arm move when applying suction to the hose on the module. i usually test by sucking on the hose and watching to see if it moves. imagining you have a milk shake on the other end helps. :drunk:  it should hold suction for at least 10 seconds when you cap it off. if its good then it will be the accelerator pump inside the carb. it looks like a tiny old school  bicycle pump piston or a plunger. These go bad from the ether in gas these days. they also are prone to grabbing dirt and scratching the tiny cylinder wall when the rubber boot cover wears out. you can hone out with a 800 grit or finer sand paper in a circular motion to remove scratches. I just throw these carbs out and get webers  :brow: . but i understand the need to keep things original

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sorry. i wasn't reading that you already have a weber. check and see if all hoses are good and check the diaphragm accelerator pump on the side of the carb for signs of fuel leaks. check the kit gaskets are in good shape. the only time webers give me trouble is when they are grabbing air from gaskets or hoses. i still think its the vacuum advance on the distributor. and old trick that i use also is to accellerate the engine manually fromk the carb until around 3 grand and suddenly choke it out with a clean towel or your hand and force the engine to suck any debris out of the carb that may be stuck. good luck.

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  • 3 weeks later...

Just to be clear.  No I am not running a webber on the DL.    I have the stock carb, and its having trouble.    Cleaned it out and re hooked the case vent hoses that had been taken off by the previous owner.   However, that didn't fix the bogging issue.   Its almost as if its running to rich.   The initial hesitation might be because the engine has to burn of the excess fuel before it can start running right.   

 

Does anyone have any other stock carb tuning suggestions?

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I just saw your post about your governer gear.  Sorry I got that one off of ebay.  If you look at my other post, don't buy the other gear that is green.   I bought it as well because it was cheep and I wanted to see if it was an adequate replacement.   Its to big. 

 

PS, if you had a leaky gasket you have a lean condition.   Lean = to much air, Rich = to much gas. 

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