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Rolf

DHLA45M: carb mounting Oring size, earth straps mounting points

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Where are the carb earth strap mounting points?

As the previous owner has not attached the two earth straps between carbs and engine block, I wonder where they have to be attached? Cannot identify the mounting points in the Service notes. Any suggestions?

What Oring thickness is needed normally for hc turbo carb refitting?

I recently got the 8 Orings for refitting the carbs to the manifold from an independent parts supplier. They are only 3.3 mm thick. The gap in the spacers (rounded outline for hc version) is 2.3mm deep and 5 mm wide. So there is only a 1mm gap between carb and spacer before thigtening the screws, then even less. According to the Service Notes it should be 1.9/2.2mm on either sides fitted.

post-3590-1205218032.jpg


Website with information and pictures PBB St Tropez convertible Esprit:

http://www.lotusespritconvertible.de/

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Rolf,

They go under 2 of the nuts that hold the inlet manifold to the block.

I also found I needed to do up the carbs a little bit further than the service notes suggest. At the recommended gap, if I pushed down and pulled up on the carbys, I did get a faster idle due to an air leak forming. I have new o-rings in mine so it's not that. I just did them up till the air leak went away under test.

Dave Everett

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On my LC, one end goes to the top cover of the carb, the other end simply goes under the carb mounting nut. This seems a reasonable path to earth. Dont know the official gauge of wire, but as its presumably to get rid of static, the load could be measured in milliamps - i.e. the wire need not be very thick.

cheers Steve

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Rolf,

They go under 2 of the nuts that hold the inlet manifold to the block.

I also found I needed to do up the carbs a little bit further than the service notes suggest. At the recommended gap, if I pushed down and pulled up on the carbys, I did get a faster idle due to an air leak forming. I have new o-rings in mine so it's not that. I just did them up till the air leak went away under test.

Dave Everett

Dave,

Thanks for the hint with the earth straps.

Do you remember the thickness and material of the new Orings you used? Viton, 4mm?

Rolf

On my LC, one end goes to the top cover of the carb, the other end simply goes under the carb mounting nut. This seems a reasonable path to earth. Dont know the official gauge of wire, but as its presumably to get rid of static, the load could be measured in milliamps - i.e. the wire need not be very thick.

cheers Steve

Hi Steve,

Thanks for the tipp, will mount them under the carb mounting nuts.

Cheers,

Rolf


Website with information and pictures PBB St Tropez convertible Esprit:

http://www.lotusespritconvertible.de/

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Hi Rolf

The earth straps on mine went to the outside lower mounting bolts for the Carb inlet manifold. I think you may be able to see this in my 'S3 HC conversion' Thread. in restoration section. Somewhere on the later pages where It shows the refurb on my Carbs. I have the old 'O' rings, so will try to measure for you later.

Daz


The need for speed can be found with a Lotus

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Dave,

Thanks for the hint with the earth straps.

Do you remember the thickness and material of the new Orings you used? Viton, 4mm?

I didn't check them before installing, but I think they would have been 4mm.

My carbs are definitely on closer than spec but it does now run right and the carbs can still move.

Dave Everett

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Hi Rolf

The earth straps on mine went to the outside lower mounting bolts for the Carb inlet manifold. I think you may be able to see this in my 'S3 HC conversion' Thread. in restoration section. Somewhere on the later pages where It shows the refurb on my Carbs. I have the old 'O' rings, so will try to measure for you later.

Daz

Hi Daz,

everytime when I look through your thread I find something helpful. Have seen the mounting points for the earth straps on the bottom of the carbs!

Thanks!

One hint for you. As you have although the 45er carbs, I have seen the service kit you installed. Have a look at the springs for the accelerator pump diaphragm. You have the weaker springs for the 40carbs I think. Check the picture for the info that the stronger springs (the one with less windings is stronger) are for the 45s:

http://www.dellorto.co.uk/merchandise/prod...PartsectionID=1

The stronger springs give you 10cc instead of 8cc volume from the accelerator pump.

I did a test drive today with the new refurbished carbs. I installed 4mm O rings made from NBR (could not get them quickly in Viton) in the spacers. Had a fine running Esprit for 30 minutes. Lost than in the lower revs one cylinder due to an air link I guess. Think the O rings made from NBR are not withstanding the heat good enough. Will install the thinner 3.3mm from my parts supplier, hope they are made from viton and get better long time result then. Looking through the 88 onward service notes, 1 mm gap between the spacers and carbs / manifold is enough, so the thinner ones may be really the right ones ;)

Regards,

Rolf


Website with information and pictures PBB St Tropez convertible Esprit:

http://www.lotusespritconvertible.de/

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