View single post by Esprit2
 Posted: 05-03-2021 06:01 am
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Esprit2

 

Joined: 05-01-2005
Location: Minneapolis, Minnesota USA
Posts: 547
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You mentioned having Lotus Spec 5 carbs, but the tag number you gave is for the Lotus 911 2.2 Litre engine used in the Talbot-Sunbeam-Lotus World Rally Cars. Which doesn't mean someone in the past hasn't re-jetted them as Spec 5

FYI, here's the Sunbeam/ Lotus 911 carb specs:
5325 P. . . . Tag Number, Rear Carb --- P = Posterior (rear)
5326 A. . . . Tag Number, Front Carb -- A = Anterior. (front)
19.129. . . . Part # = DHLA 45E x 2
45mm . . . . Throat
36mm . . . . Choke
8011.1. . . . Auxiliary Venturi
158. . . . . . . Main Jet. . . . . . . . . . Spec 5 = 160
230. . . . . . . Main Air Corrector. . . Spec 5 = 230
7772.8 . . . . Main Emulsion Tube
58. . . . . . . . Idle Jet . . . . . . . . . . Spec 5 = 50
7850.9 . . . . Idle Air Corrector. . . . Spec 5 = 7850-7
60. . . . . . . . Accel Pump Jet (p/n 7851)
38V 42H . . . Accel Pump Jet (alternative) . Spec 5 = 38V 42H
95. . . . . . . . Starter Jet
7482.3 . . . . Starter Jet Emulsion Tube
170. . . . . . . Inlet Valve
7298.1 . . . . Float
10 gram . . . Float Weight . . . . . . (Alternate 8.5 gram. . Float Weight)
14.5 - 15.0 . Float Height. . . . . . . (Alternate 16.5 - 17.0 Float Height)
10.0 cc . . . . Accel Pump Discharge, cc in 20 full strokes
900-1000 . . Idle Rpm
2.0 - 3.0%. . Idle Carbon Monoxide Emissions

The float height depends upon the float weight used. At different times, two different float weights were specified, with two different corresponding float heights.

You wrote:
> I did check the floats (8.5 gms) and adjusted them accordingly.

You stated that you checked the float weight (8.5 grams) and set the height accordingly, but you don't mentioned what height you used. A 10gr float is set to 14.5 - 15.0mm, and an 8.5gr float is set to 16.5 - 17.0. If the float is set too high (smaller number) for a given weight, then the fuel level will be too high and can overflow into the throats.

However, that should affect both throats on a carb with the float set too high, and not just one. You indicate that only the #4 throat is leaking fuel, which does not compute. For a single throat leaking, I'd be looking into the fit of the auxiliary Ventury in the throat, and make certain the set screw is secure.

Regards,
Tim Engel

Last edited on 05-08-2021 01:59 am by Esprit2