A long time ago, LLoyd and I got my carb working with my 12a. I have grown tired and would like to modify the idle holders correctly. So, I ordered new idle holders and then did research to find out that I need a 1.4mm bleed hole drilled. I have looked locally and no one around the central coast of Cali will actually seal the cavity and then drill the bleed hole for me. I was just wondering what kind of metal filler should I use to fill the cavity before drilling the bleed hole?

 

Silver solder? Just a guess.

 

Is silver solder just regular solder? Anyone else any ideas?

 

Regular solder may be too soft, thats why I said use silver. I know its harder.

 

Try a jewler or gunsmith...worth a shot (pun intended)

 

new undrilled idle jet holders can be ordered directly from Dellarto. That is where i got mine. have to look in my box of extras might have two already drilled for you will look tomorrow.

 

Interesting because both sets I've order from dellorto have been not drilled but they still have a cavity which when drilled can let to much air in

 

Here are a few photos of the cavity, these are the brand new ones I have received from dellorto. The cavity goes down about 80% of the top chamber, so if a hole was just drilled it could let in to much air ( a problem that Lloyd and I dealt with 7 yrs ago)

 

Also to mention, these are idle jet holders for a 12a

 

A 1.40mm hole is much smaller than the cavity. It's the size of the hole you drill that determines how much air will bleed off, not the size of the cavity. I don't see a problem here. Just make sure you drill it in the exact center of the cavity.

 

See about getting a set of small drill bits. Drill Bits and Pin Vises

 

I have not had problems with too much air except when drilled to large. I started at .8 mm and worked up to meet my tuning needs. those jets are just fine to use. I can not find any extras i thought i had sorry.

Joe

 

Well got them drilled to 1.4 mm today, threw them in an car would not idle. Was able to get an idle with the mixture screws almost all the way out, but any rev at all would kill it. I have a feeling that I got it drilled to much at the machine shop. Maybe 1.4mm is too much for carb. Well either back to the drawing board measure, acquire new idle holders from Britain and drill again( this time on my own with a dremel ), or get rid of this carb.

 

Damn Ron!! New carb time baby!

 

what jets are you running currently and what are the mains, holders and air bleeds?

 

Jet Size Notes
Main Emulsion Tube #7772.8
Main Fuel Jet #230
Main Air Jet #230
Idle Holder/Emulsion Tube #7850.4
Idle Jet #75
Accelerator Pump Jet #90 Not positive on this.
Needle and Seat #300 Pretty sure as it's the only one that RB had in their catalog.

 

I posted this from gruntled because it is my setup that i posted in the thread that I installed this carb