G'day, ive just finished fitting a 40mm DHLA dellorto to my clubbie,replacing the old 1 1/2 SU, the jetting is,
32mm chokes
145main jets
200 air correctors
40 pump jet
55 idle jet
7772.5 emulsion tube
aux vent 3
this was a base jetting set up that vizard recomended
My engine is a 998, bored 40thou, 649 cam, ported head,bigger valves, 10:1 comp, 2inchexhaust with extractors.
My problem is i cant get it to take off smoothly, it hessitates, splatters and backfires, the idle adjustment is 2 3/4 turns out , i have tryed different adjustments, this is the better setting, Do I need to change my idle jet, as i think its lean on the progresstion, off idle, and do i need to change the timing , since i have changed from an SU? curently 8 degrees BTDC?

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(KILL #53) Help MotherEarth, squash a Bug.

I believe your 200 air correctors are too large, I've never been able to get 200s to work on any Mini. Try 180 airs.
145 mains are in the ballpark to start with, and the idle jets.
If the carb is off an Alfa and never used on a Mini, you may need to increase the accelerator pump stroke by a tightening the nuts a couple of turns.

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

You are in the park as the good Dr said. If you are running a little off in the progression phase, go to a 45 pump jet and should make it a little better. The problem with mucking around with one thing is you usually throw something else out. Write down what you change and it is all trial and error. I would suggest with the 45 pumps you go to the 30mm chokes as it will increase your air velocity(you will hear gurgling from the throats rather than a hiss if you retain the 32mm - needs to hiss...lol). The other thing to look at is the progression hole covers as these can leak air in if they are loose and while they are off, see if any of the holes are blocked.

Good luck. Go the Dellorto crew.

Hooroo

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Rob Forsyth
Miniot!!

well i went to carby services today bought some 180 air correctors, first i screwed up the pump jet, this made a big difference when taking off but it was still running rough, then i fitted the 180's, these cleared it right up, but it still hesitates off the line,but its fine in between the gear changes.Once you are off, the power is great, but the extra torque is amazing, in 4th it just keeps pulling, with the old su it use to die off at high speed.or when you came into a rise...not now!
I also found it was a tad lean so i changed the mains to 150's, which also helped take off a bit, ill try some 45 pumps and see if that helps.
Thanks Doc, CPOCSM for your help

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(KILL #53) Help MotherEarth, squash a Bug.

Don't stomp the throttle at idle, you'll drown it and it'll gasp...
Feed it in gradually, it should take full throttle from 2000 approx.

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

I know, thats what i was doing, feeding it, not flooring it! this seems to make it worse, I can either rev it up and drop it, which i really don't like doing, or feed half then floor it,then lift, then floor it, these seem to be the only ways i can get it to move with little hesitation, the later method seems to mean to me that its lacking fuel, and by "pumping" the throttle, giving sufficiant fuelthrough the accel pump. Do you think it's the pump jets or is it the idle jets, as these are the ones that are used on initial acceleration or progresion??

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(KILL #53) Help MotherEarth, squash a Bug.

Maybe a pump jet is part blocked.. take carb off, with fuel in the float bowl.
Open the throttle fully, it should spray 2 equal streams of fuel out past the butterflies.
If not remove jets, clean with carb cleaner and compressed air, retry.

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

And a good word of advice - DO NOT look down the butterflys when you pump it if you have side spitters...I learnt from bitter experience there...lmao. Both Mk 1 optics full of fuel and carb cleaner...not a nice feeling when you are staggering around a cluttered garage trying to find the wash basin.

Hooroo

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Rob Forsyth
Miniot!!

Is the dellorto the same as a 40 dcoe weber, i am after some advice aswell, the setup on my weber Contains 32mm chokes, 4.5 venturi, 145 main jets, 50f8 idle jets, 50 acc pump jets, 180 air correctors.
the engine i am putting it on is a 1100 +20thou oversize LCB extractors, std cam, std 12g202 head, i am planning in the next 6 months to port and polish the head and fit bigger valves. Would the setup i have on the weber be suitable for the engine i have, or does anyone have any suggestions on things to change on the weber

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77 Leyland Clubman
1293cc, LCB extractors, pulsar dizzy (recurved), cooper s disc brakes, 40DCOE Weber

Weber is not `identical' to a Dellorto, but size for size, the jetting is close.
Yours sounds close enough to run, I'd then take it to a dyno and stick an A/F ratio meter on it.

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.