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I'm currently rebuilding/refurbing my carbs.

They are Spec9 DHLA45 (Engine is 912NA(SC)).

However, I have just checked the idle jets, one is 45 the other 60?

Should they be different? hmmmmm?

Does anyone have a list of "ALL" the correct standard jets?

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Excel manual gives spec 9 as

37mm choke

160 main jet

230 main air corrector jet7772-8 main emulsion tube

55 idle jet

7850-9 idle jet holder

8.5g float weight

float height 14.5-15.0mm

170 float needle valve

50h pump jet

95 starter jet

7482-3 starter emulsion tube

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Spec 1

Carb Type ...................... DHLA 45E

Choke ............................ 38 mm

Main Jet ......................... 142

Main Air Corrector Jet ... 110

Main Emulsion Tube ...... 7772-5

Idle Jet ........................... 55L

Idle Jet Holder ............... 7850-1

Float Weight .................. 10 gr

Float Setting Height ........ 16.5 - 17.0 mm

Float Needle Valve ........ 170

Pump Jet ........................ 45

Starter Jet ...................... 70

Starter Emulsion Tube .... 7482-1

Power Jet .......................... ---

Slow Running Speed ....... 900 - 1000 rpm

Idle CO Level (hot) ......... 2.0 - 3.0%

Spec 3...

Carb Type ...................... DHLA 45E

Choke ............................ 35 mm

Main Jet ......................... 130

Main Air Corrector Jet ... 110

Main Emulsion Tube ...... 7772-5

Idle Jet ........................... 56

Idle Jet Holder ............... 7850-6

Float Weight .................. 10 gr

Float Setting Height ........ 16.5 - 17.0 mm

Float Needle Valve ......... 170

Pump Jet ......................... 45

Starter Jet ....................... 70

Starter Emulsion Tube ..... 7482-1

Power Jet .......................... ---

Slow Running Speed ....... 900 - 1000 rpm

Idle CO Level (hot) ......... 2.0 - 3.0%

Spec 5

Front ............................. E907E0789F

Rear .............................. E907E0790W

Tag Number

Front ............................. 5295A

Rear .............................. 5294P

Carb Type ..................... DHLA 45E

Choke ........................... 36 mm

Main Jet ........................ 160

Main Air Corrector Jet ... 230

Main Emulsion Tube ....... 7772-8

Idle Jet ........................... 50 (Too lean! Try 55-58 range)

Idle Jet Holder ............... 7850-7

Float Weight .................. 10 gr

Float Setting Height ........ 16.5 - 17.0 mm

Float Needle Valve ........ 170

Pump Jet ........................ 38V 42H

Starter Jet ....................... 70

Starter Emulsion Tube ..... 7482-1

Power Jet .......................... ---

Slow Running Speed ....... 900 - 1000 rpm

Idle CO Level (hot) ........... 2.0 - 3.0%

Spec 9

Carb Type ..................... DHLA 45E

Choke ........................... 37 mm

Main Jet ........................ 160

Main Air Corrector Jet ... 230

Main Emulsion Tube ...... 7772-8

Idle Jet .......................... 55 -58

Idle Jet Holder .............. 7850-9

Float Weight ................. 8.5 gr

Float Setting Height ...... 14.5 - 15.0 mm

Float Needle Valve ...... 170

Pump Jet ...................... 50H

Starter Jet ..................... 95

Starter Emulsion Tube ... 7482-3

Power Jet ......................... ---

Slow Running Speed ..... 900 - 1000 rpm

Idle CO Level (hot) ....... 0.7 - 1.5%

At the moment, I'm basically running Spec 9 in both a 2.0 907 Eclat and a

2.2 907 Esprit.

Spec 10 ... 10.9:1 or 11:1 compression, 104 or DS2 cam, 2.2 liter.

Carb Type ....................... DHLA 45E

Choke .............................. 37 mm

Main Jet ........................... 135

Main Air Corrector Jet ... 150

Main Emulsion Tube ...... 7772-8

Idle Jet ............................. 56 (maybe a little lean, try up to

58)

Idle Jet Holder ................. 7850-9

Float Weight .................... 8.5 gr

Float Setting Height ........ 14.5 - 15.0 mm

Float Needle Valve ......... 170

Pump Jet .......................... 45H

Starter Jet ......................... 80

Starter Emulsion Tube ..... 7482-3

Power Jet .......................... 70

Slow Running Speed ....... 900 - 1000 rpm

Idle CO Level (hot) ........... 0.5 - 1.5%

Esprit Naturally Aspirated 2.2 liter 912, 1988 Onward

Tag Number

Front ................................ 5395A

Rear ................................ 5394P

Lotus Part Number

Front ............................. A912E2336F

Rear ............................. A912E2337F

Carb Type ....................... DHLA 45D

Choke .............................. 37 mm

Main Jet ........................... 135

Main Air Corrector Jet ... 150

Main Emulsion Tube ...... 7772-8

Idle Jet ............................. 56 (maybe a little lean, try up to

58)

Idle Jet Holder ................. 7850-9

Float Weight .................... 8.5 gr

Float Setting Height ........ 14.5 - 15.0 mm

Float Needle Valve ......... 170

Pump Jet .......................... 45H

Starter Jet ......................... 80

Starter Emulsion Tube ..... 7482-3

Power Jet .......................... 70

Slow Running Speed ....... 900 - 1000 rpm

Idle CO Level (hot) ........... 0.5 - 1.5%

Pump Delivery .................. 8cc / 20 strokes

Pump Lever Clearance ..... 0.1 +/- 0.05 mm

Fuel Delivery Pressure ..... 4.0 +/- 0.25 psi

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If some one has been playing with your carbs, it may be worth getting hold of a jet gauge, which is basically a tapered/callibrated needle.

When I had jetting problems it turned out that a previous owner had fitted jets that had been bored out, and the only way to tell was by using a gauge!

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So 45 and 60

As area is Pi r to the power of two

45 x 45 = 2025, 60 x 60 =3600 total of 5625

55 x 55 = 3025, 2 of means 6050 .

Overall the jet sizes averaged out close, just 2 cylinders would be naturally really lean and two naturally really rich. Must have ran awfully at idle or bean a really nasty job to adjust to get it to idle.

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Aren't you confusing radius with diameter? Pi Rsquared....or Pi Dsquared/4 gives the area. If you check with the DHLA bible, you find that the Lotus slow running jets - which also work through the progression phase up to where the main jet chimes in - are at the lean end of what is recommended, so if they get gunged up then the whole power curve gets messed up; mine got a flat spot at 70 to 80 mph, just where you have to cruise, these days......

Scientists investigate that which already is; Engineers create that which has never been." - Albert Einstein

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Aren't you confusing radius with diameter? Pi Rsquared....or Pi Dsquared/4 gives the area. If you check with the DHLA bible, you find that the Lotus slow running jets - which also work through the progression phase up to where the main jet chimes in - are at the lean end of what is recommended, so if they get gunged up then the whole power curve gets messed up; mine got a flat spot at 70 to 80 mph, just where you have to cruise, these days......

Yep in a way I did diameter squared, but as both had no scale mentioned, it could easily have been given in 1/200s of a mm instead if 1/100ths so the maths is still the same.

I still need to get round to doing the idle mixture adjustments on the gold Excel, I can hardly see a colour difference between absolutely rich and absolutely lean using the colour tune, but I know it's making a difference as I can lean it down too much and so loose the fire. I'll probably just resort to assuming all four ports are roughly even and use the analyser up the exhaust pipe.

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