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Throttle butterfly

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jmwuva05

jmwuva05

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Dumb question here. While I was rebuilding my H1 carburetors I think I put one of my throttle butterflies in backwards(the car would not idle slower than 1500) I took them off todayand found that I have the tapers onthe butterfly edge in opposite directions from one another. Which was is correct taper facing into the manifold bore or outwards. thanks in advance.
 
Hmm, taper should be so that the butterfly edge is snug against the throtle body when it is closed.

Would that make the taper toward the outside on the top and the inside on the bottom?
 
I figured it out. It makes the tapered end toward the outside. I remember reading somewhere that when the butterfly is closed you shouldn't be able to see light throw the shaft. I can see small amounts of light through the front carb but not the rear. Could this indicated the inside of the body is worn?
 
Are you sure it is closing all the way? ie; the idle screw is backed all the way out. More common for th shaft to wear. Butterflys will wear side to side sometimes digging into the wall of the carb. I would assume if the carb itself was worn you still would see no light as the two pieces would wear in together and seat together?!?!?
 
When the throttle is closed the taper on the throttle plate and the bore of the carb. should be parallel. You need to leave the throttle plate screws slightly loose and open and close the throttle several times seating the plate for a good fit and than tighten the throttle plate screws and recheck the fit. The light test is good for this. The ends of the throttle plate screws should be lightly staked with a chisel to prevent them from backing out and being sucked into the engine while it is running. Be sure to have a back up bar on the screw head when staking so you do not bend the throttle shaft. Recheck the plate fit after staking.
 
Very interesting, startech!

Is there not a Locktite that might do the job? Or is there too much gas flying around for a liquid thread locker to work?
 
Locktite is fine but still bend the ears on the screws. They are brass and a small screwdriver in the split end with a bit of a twist will do the job just fine. They just need to be spread a bit not flatened.
 
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