Leaking carb.

[Steven162]

So, the scars on my hands, forearms, elbows, forehead, etc, are nearly heeled up, I can nearly stand up straight and move my arms properly and my hands are nearly clean after a weekend of removing my waterpump and then another weekend of putting it back on after it was refurbed.

 

The car has been smelling of petrol a bit after a run so I ran my hand under the carbs, the front carb is wet with fuel underneath (wet, not dripping) with the engine off but the pump running, when I open and close the throttles with the cable between the carbs (again engine off but pump running, and pump off for a while) it drips fuel onto my fingers. There is no sign of fuel when looking at the top of the carbs.

 

Any idea where to look on the carbs? I have the Hammil book which I will be reading while I work away next week and a Lotus workshop manual, just wondering if any body has seen this before.

 

Car is 87 Turbo HC

 

Thanks

 

Steve

[Paul Coleman]

When was the last time you replaced the accelerator pump diaphragms?

[gvy]

Same here.

If those pump diaphrams are punched or leaking , the carb gets wet underneath.

 

When was the last rebuild of your carbs?

 

Geert

[simon a-b]

I just did this on my rear carb.  I took them off the car to do it, but I guess if you wanted you could do it in situ... the diaphragm is pretty easy to change, stopped my leak immediately.  Don't need to emphasise the risk of leaking carbs on these cars!

[Mike6]

My later carb turbo had some leaks under the rubber 'o' rings where the carbs attach to the manifold. I would check these in the first instance.

[Steven162]

All fixed, 2 diaphragms from Eurocarb and a couple of hours work. I had to remove the diffuser, plenum backplate and plenum cover to get access to the lower carb mounting nuts but I had all this apart last year so it was OK. Those shiny trumpets that nobody sees! I did the front carb off the car and the rear one off the manifold but still connected by the throttle and choke cables.

 

20 miles and no leaks - thanks for the advise.

 

Steve   

[Steven162]

A bit of advice when doing anything with the carbs, if you disturb the link between the carbs, even by a small amount they will need re-balancing. I loosened one screw only when I removed the carbs and tightened it up (not fully!) when I refitted but on checking the balance there was at least 1 inch difference on my carbtune between the two. Its a very satisfying thing to do though!

[molemot]

Speaking as the Devil's Advocate....how do you know the carbs were balanced before?(!)

[Steven162]

I balanced them a few months ago!!!