Hi, need a little help on adjusting a float on teapot carb. Ordered a carb kit from Mac's. The kit came with a seat and needle, the needle has a flat top on it. Are there correct specs to adjust the float? Or, do you test it on your own till it runs right? Is it the higher the float in the bowl the more gas will digest through the carb? Thanks.
Adjusting float
- Thread starter dgmgohl
- Start date
Charlie ny
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dg,
Hopefully Sal will join in here. In my experience bending the float tang so
the free end of the float is slightly lower than the hinged end is optimal. Slightly lower
is between 1/32" and no more than 1/16".
Charlie ny
Hopefully Sal will join in here. In my experience bending the float tang so
the free end of the float is slightly lower than the hinged end is optimal. Slightly lower
is between 1/32" and no more than 1/16".
Charlie ny
51 MERC-CT
Well-known member
Thought you said you had it set as you said "I have the float set to spec. 7/32"
If that's the spec. that is what it should be with fuel in the bowl ±. Assuming its on the car.
A little too low and engine may stumble. A little too high it may be too rich.
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51 MERC-CT
Well-known member
Try bending the float to raise the fuel level 1/16"
scicala
Well-known member
THe correct float level spec in the Holley manual for '49 thru '53 Merc two barrel teapots is 7/32". I usually set it about 1/32" lower just for a fighting chance against flooding over or to avoid wet seeping gaskets. Same with the '49 thru '51 Lincoln carbs.
A slight change in fuel level like that has no affect on making a car richer or leaner.
I don't think raising the fuel level will help with a bog or hesitation. There is another issue causing that, such as weak or no accel pump squirt, sloppy accel pump linkage (causing a delayed squirt) or even ignition issues.
Sal
A slight change in fuel level like that has no affect on making a car richer or leaner.
I don't think raising the fuel level will help with a bog or hesitation. There is another issue causing that, such as weak or no accel pump squirt, sloppy accel pump linkage (causing a delayed squirt) or even ignition issues.
Sal
51 MERC-CT
Well-known member
The reason for the recommendation to raise the fuel level, is because a similar situation on an 885 Holley was cured by doing so.
scicala
Well-known member
Didn't read about that one. Was the 885 float raised above the spec setting of 7/32" ? Or was the float lower than spec to begin with ? Just trying to find out for future help. Thanks
Sal
51 MERC-CT
Well-known member
Insofar as the Holley 885 is concerned.
It's not the float level spec. that is important but the fuel level spec. ( which on the 885 is 1/2" from top of bowl ) that determines how the carb will perform.
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scicala
Well-known member
Correct, and 7/32" float level is supposed to give you the 1/2" fuel level. I'm sure the fuel pressure has something to do with it too.
On the car you were talking about that had the hesitation fixed, do you know about how high the fuel level was set ? Thanks.
Sal
51 MERC-CT
Well-known member
As I recall, the initial (dry) float setting was set, and after installation,
the performance problem was corrected by setting the fuel level (which was low) to the 1/2" spec.
To me, it seems obvious that the dry float setting works only if there are
not any anomolies in the associated components.
It's the fuel level that matters.
rotorwrench
Well-known member
Many carb designs will run OK within a range of fuel level in the float bowl. Holley likely figured out the most optimal setting on a flow bench. I'm sure the fuel level varies some within the range of operation for most any carb. The float valve may not ever shut off during high throttle operation just to maintain some fuel level in there. The fuel level in there provides a column of fuel in the metering well tube circuit for good air fuel atomization. Too much float level and it can overflow the vent port at the top of the circuit. Too little and the atomization won't be optimal as designed but it may still function to a point.