Two Questions

[1985C10]

First, what is the best way to remove the idle down channel restriction.  Mine are way too big.  There is no straight shot from underneath.  I thought about extracting it with a screw in similar fashion as the idle tube removal.  Is there a better way?

Second, is just a matter of curiosity about the sec. POE restriction on my 17059213.  I measured it (carelessly) the first time to be about .052".  Well that was the size of the discharge hole, but not the restriction, so I was way off.  It actually measures about .033".  Is it normal for it to be so small?  If I increase it to .054", as I intend, it will grow by about 2.5x (in area).

[Cliff Ruggles]

The idle down channel restrictions are easy to remove.  I find a drill bit from the index that just catches them, and spin them out with my drill.

Once in a while this doesn't work, so I go to the next size and do it again.  Worst case scenario you end up carefully drilling them out, but use care not to oversize the bore they are sitting in.

We have new down channel restrictions available, call the shop if you need them.

Leave the well restrictions small, .033" is OK for most applications.  If you drill them too large, they will continue to feed fuel to the secondary side of the carb at full throttle....Cliff

[1985C10]

Leave the well restrictions small, .033" is OK for most applications.  If you drill them too large, they will continue to feed fuel to the secondary side of the carb at full throttle....Cliff

No, not the well restrictions.  Those are .039" already.  I meant the POE restrictions in the air horn at the discharge point.  Going from .033" to .054" just seems like such a huge change.  I was curious if this is common for factory calibration.

[Cliff Ruggles]

I've never seen any discharge holes that small, at a minimum I'd open them up to .045-.050".....Cliff

[1985C10]

Well a #55 bit fits in the clearly visible part of the discharge hole, but there is a smaller #66 hole before you break into the passage that the brass straw goes in.  I thought that was a little strange.  Of course I've already discovered that my carb is a bit of an odd ball.

.037" idle tube
.062" down channel
.065" upper idle bleed
.062" lower idle bleed
.105" idle bypass air
.084" mixture screw holes w/ factory tamper plugs in place

I've got the bleeds to .070/.070, idle mixture holes to .089", removed the down channel restrictions, and I'm working on an aluminum (or brass) plug for the idle bypass so I can bring that down to about .080".  Havin' fun.

[Cliff Ruggles]

We sell drive in restrictions with a chamfered leading edge, much easier than trying to fabricate something....Cliff