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Wed Mar 12, 2014 7:58 pm

I have a solex carb that apparently has the throttle plate off-center.

When I look through the carb from the top with the butterfly completely closed, I can see daylight around one edge. This is leaving 2 progression holes exposed because the plate cannot close up against the wall completely on that side.

I assume I can just loosen the screws holding the plate to the shaft and move it a little to close better? I know the screws are peened over but they should still loosen up just a bit right? I am no carb expert and I don't want to break anything! Thanks guys.

Wed Mar 12, 2014 8:28 pm

If you have a Dremel, grind off the peened area on the underside first, then unscrew.

Thu Mar 13, 2014 3:37 am

Don't hold the carb in one hand to do it. If the screwdriver slips it'll go into your hand. Ask me how I know. :oops:

Thu Mar 13, 2014 5:47 am

also, once you loosen the screws, I've found that it's easiest to gently open the throttle and slap it back shut, to center the plate. Trying to do it by hand can be frustrating.

Thu Mar 13, 2014 6:31 am

Thanks for the tips guys, I'm going to give it a try, hopefully itcenters up enough to cover the progression holes. I think I will try to just crack the screws loose to see I I am get the plate to move before taking a dremel to it.

Also just wondering if adjusting the throttle plate like this is normally something you have to do yourself on a new carb? Or should it be centered nicely out of the box?

Sun Mar 16, 2014 6:23 am

One more question about the same carb.

The throttle lever has a bit of play on the shaft, if i tighten down the nut a little bit to elliminate the play, then the throttle shaft starts getting tight and will not return closed all the way. Whats wrong here? This is a new carb.

Sun Mar 16, 2014 8:39 am

platatomi wrote: One more question about the same carb.

The throttle lever has a bit of play on the shaft, if i tighten down the nut a little bit to elliminate the play, then the throttle shaft starts getting tight and will not return closed all the way. Whats wrong here? This is a new carb.

When you tighten the nut, you are changing the centerline of the butterflies. Try adjusting the shaft with both butterflies loose then center the butterflies.
Paul

Sun Mar 16, 2014 8:52 am

The throttle shaft is SUPPOSED to have a bit of sideways play after all the nuts, etc are completely tightened. In fact, that's how
the butterfly plate is able to self-center and close completely. You will never get the plate to perfectly center in all positions with
no sideways play. Seems like your carb has been assembled wrong, or they left out a washer or something. You say the carb is "new",
but how do you know it's not a return that someone's been messing with?

The slots in the staked screws will usually rip out without the screw turning, unless you remove the staking first.

Sun Mar 16, 2014 9:50 am

kreemoweet wrote: The throttle shaft is SUPPOSED to have a bit of sideways play after all the nuts, etc are completely tightened. In fact, that's how
the butterfly plate is able to self-center and close completely. You will never get the plate to perfectly center in all positions with
no sideways play. Seems like your carb has been assembled wrong, or they left out a washer or something. You say the carb is "new",
but how do you know it's not a return that someone's been messing with?

The slots in the staked screws will usually rip out without the screw turning, unless you remove the staking first.

By staked you mean peened? I have not taken it apart yet but it does not look to me like they have been peened. The screws have rectangular depressions in the ends. In this picture you can see how far off the plate is, not closing enough.

Sun Mar 16, 2014 12:13 pm

I doubt the butterfly is the source of the problem. There's clearly something very wrong with the parts attached to the shaft on
the outside, because tightening any nut there should not cause binding up. None of those external parts should be contacting
the carb body in any way.

It looks to me like the screw ends have been "peened"/"staked" with a diamond-point chisel or similar tool. The purpose being to
expand the metal and lock the screw in place. Yours is odd, though, because every Solex carb I've worked with had the slotted screw
heads on the underside of the butterfly. Are you sure your carb hasn't been assembled with the butterfly plate upside down? Can't say
I'm familiar with the model you show, though.

Sun Mar 16, 2014 2:15 pm

kreemoweet wrote: I doubt the butterfly is the source of the problem. There's clearly something very wrong with the parts attached to the shaft on
the outside, because tightening any nut there should not cause binding up. None of those external parts should be contacting
the carb body in any way.

It looks to me like the screw ends have been "peened"/"staked" with a diamond-point chisel or similar tool. The purpose being to
expand the metal and lock the screw in place. Yours is odd, though, because every Solex carb I've worked with had the slotted screw
heads on the underside of the butterfly. Are you sure your carb hasn't been assembled with the butterfly plate upside down? Can't say
I'm familiar with the model you show, though.

I got the thing taken apart, I do not think the screws were peened because they did simply unscrew, although with difficulty. Once the butterfly screws were loose, I could tighten the shaft nut withiut binding, so it must have been the butterfly that was sticking.

I think the butterfly is in correctly because the little square cut-out area is facing up. I was hoping that by loosening the screws and allowing the plate to center, the progression holes would be covered with the plate closed. It atill does not cover the first two holes, the plate is simply too big to close fully.

I agree with you, something is way wrong with this thing, nothing I can do about it because believe it or not this is the 2nd exchange carb they have sent me, last one had the same problem with the butterfly not closing all the way and this is what they replace it with.

Sun Mar 16, 2014 2:53 pm

Can you post a photo of the edge of the butterfly?
Paul

Sun Mar 16, 2014 3:41 pm

Sure.

Sun Mar 16, 2014 4:45 pm

have you tried running it on the car?, and you've made sure none of the linkage is hitting the stops? also the shaft is supposed to have a little play, keeps the wear down to a minimum-tightening the nut too much can cause the shaft to seize in the bushing/bearings

Sun Mar 16, 2014 4:52 pm

From the photos, there appears to be burrs around the progression holes? Are you sure that it's not hanging up on a burr?
Paul

Sun Mar 16, 2014 5:08 pm

75smith wrote: have you tried running it on the car?, and you've made sure none of the linkage is hitting the stops? also the shaft is supposed to have a little play, keeps the wear down to a minimum-tightening the nut too much can cause the shaft to seize in the bushing/bearings

It hasn't been on the car yet. The last one had the same problem and it was un-tunable so I figured why even put it on before all hope of solving these problems is lost. I'm sure its not hitting anywhere else, it still won't close with the throttle body removed from the carb. I was not sure how tight the nut should be, it was not more than finger tight when I got the carb and figured it should be tighter than that.

Paul Wilson wrote: From the photos, there appears to be burrs around the progression holes? Are you sure that it's not hanging up on a burr?
Paul

I did notice the burs, its possible it may be hanging there but the plate seems to be seating fully all the way around so I don't think it could go any farther anyway. But I will try removing those burs just in case, how should go that? Is it a bad idea to smooth that off with sandpaper?