I wana reduce the size of my main jets in my dellorto side draught.

I have been told that I could just solder the holes up and re drill them to suite

but I want to check with u guys first

thanks in advance.

go to carburettor services at burwood and just get smaller sized jets, they are very pricey some jets are between 15-21 bucks each !!!

look in to what emulsion tubes you should have in if your number is 7772.1 that is about norm with 1.10 jets dont drill as it may not be right and very hard to tune

Yes you can just solder then redrill with the drill size you want. It beats paying out for new jets..

Solder and redrill is not as accurate as factory jets but a hell of a lot cheaper.

You can buy drills in 0.05mm steps from precision engineering sales companies. You will also need a suitable holder for the jet to drill through the solder.

tumanycuz thats exactly what I have 110 mains and those tubes ya said but its way to rich only drives at full throttle and just on throttle i have 52 idol jets and 28 venturis and today i made some 100 main jets and that is still too rich Im thinkin around 80-90 mains does this sound right?

Kegs the carby just got built at CSC and the jettin has been way off so far and there is a fuel leak comin from the big screw thing near the idol mixture screw and after paying $355 I wasnt too hapy but Im sure it will all be sorted out soon I hope.

Just wanted to know if the solder thing was ok so I can solder up some jets and start around 80 and work my way up till I find the right size then I will buy some made ones. Sounds like the smart thing to do.

Thanks all for the replys so far.

Something I read in a book on holleys, is that when you drill out a jet, you lose some of the shape in the hole. The hole in a jet actually has a waist in it. when the fuel (Plus air from the air bleed) pass through this waste it speeds up. Then as it exits the waist, the pressure drop aids atomisation of the fuel. the book i read claimed that if this waist was removed by drilling, it was possible for a bigger hole to actually pass less fuel than a smaller one. Plus, drills cut on oversize hole too.
But in saying that, with jets being the price they are, I guess getting them within cuweee with a drill, and then buying a new one is ok.

You say it runs OK when you open the throttle right up?
Does it idle?
When does it start to run rich? Just off idle?

Remember they have a progression circuit in the carby that acts off throttle until the main jet comes online, this progression side could be causing your running rich.

I have just bought a dellorto/webber book today and im goin to read it tomorow so i can fully understand what might be goin on.

Whats actualy happening is

Idols fine at around 2.5 CO @ 900-1000rpm with 52 idol jets and adjuster screws out about 2 turns.

When I put it in drive (yes an auto) the rpm slows down just like all auto cars thats no problem, but when I take off from stopped the car nosedives if I use over 1/5th throttle.

So to accelerate to say 60K's I would have to take off using no more than 1/5th throttle till I can go no faster (bout 30-40K's) then I have to progress streight to full throttle where it would nose dive for a seccond then start powering along.

The main jets are 110 the air correctors are 160 and the emulsion tubes are 7772.6

Also the vaccume tree for the auto and the dizzy only plugs into one side of the manifold (one side of the carby) will this affect the running of the engine?
Because its affected the auto, it wont change to third till after 80K's.

MLS do u mean even though it idols alright it still might be the idol jets and air correctors that might be suspect?

check out your idle emusion tube they need to be 7850.2 that is why you have no down low and run timming at about 14deg with jet size of no more than .45 or you could run 7850.3 thats my happy place for my tiwn carbs