Kevin.....
The float height should be set with the float just touching the
spring-loaded needle. Do not depress the spring.
It is possible to remove the jets with the carbs on the car, though it is
somewhat difficult to get at the Posi-drive- (or, sometimes, Phillips-)
headed screw that attaches the choke linkage to the jet body. And do note
which side of the plastic body the linkage attaches to; I've seen many where
a DPO has attached it to what appears the logical side but which is, in
fact, the wrong side!
Another thing to be careful of, both when doing the job on or off the car,
is to make sure the plastic tube goes through the rubber o-ring at the base
of the float bowl. Many times, in removal and refitting, this o-ring gets
pinched by the tube and its nut, resulting in a partial blockage. The car
will then run at idle and low speed but have inadequate fuel flow to sustain
higher speed driving or pulling up hills.
Lawrie
British Sportscar center
-----Original Message-----
From: Kevin Brown <MGTRAutoXr@sprintmail.com>
To: MG Mailing List <mgs@autox.team.net>
Date: Saturday, October 03, 1998 6:51 AM
Subject: MGB Float Adjustment
>I need to adjust the float level on the SU carburetors of a '67 MGB that
>I am trying to resurrect. The Haynes manual say to flip the float bowel
>cover over and adjust the floats so that they clear the rim of the cover
>by 1/8" in the center. While that all seems straight forward, my
>question arises from the fact that the end of the needle valve that the
>float presses against is spring loaded. (I have no clue if this car has
>stock needle valves or not!) Should the 1/8" clearance be obtained with
>the float just touching the end of the needle valve or with the end of
>the needle valve pushed in? It makes quite a bit of difference in float
>height and the manual doesn't say anything about it.
>
>Also, since the car will only start and run for about 10 seconds, I need
>to take the jet and the tube running from the float bowel to the jet off
>and clean them. Can this be done easily with the carbs on the car or is
>it better to take the carbs off? Right now I'm just trying to find out
>what kind of shape the engine is in. If I go ahead and restore the car
>I go ahead and rebuild the carbs. Considering that the car has sat for
>16 years, the engine seems to be in good shape, no smoke and good oil
>pressure. Also, all the gauges and lights work. I just need to get the
>carb situation squared away and rebuild the clutch and brake hydraulics
>to get the car on the road. Thanks!
>
>Kevin Brown '67 MGB '65 MGB '71 MGB '74 TR6 '76 TR6 '89 MR2 '98
>GTP
>Odessa, MO
>
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