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Paul Coleman

Popping and hot exhaust

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My S1 has a full stainless steel exhaust system from SJ but the back box gets so hot it has blistered the paint on the rear valance. Obviously it's not running correctly butI don't know why.


A few people have suggested air leaks and I did have an air leak on the exhaust which I've sealed.


I had the car MOTd the other day and the CO was 3.9% (max = 4.5%) and the HC was 199ppm (max = 1200ppm) so it doesn't appear to be running lean as was suggested a while back. Steve at SJ tells me that the back box shouldn't get hot so I have something seriously wrong.


I did balance the carbs with a manometer and they were pretty good. So I'm at a lossas to what to do with it.


It has been suggested that changing the timing to 10 or 12 degrees may help (it's currently set at 8 degrees).


Has anybody had similar issues and managed to resolve it?


Thanks, Paul.

Edited by Paul Coleman

Lotus Esprit [meaning] a 1:1 scale Airfix kit with a propensity to catch fire

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How did you get on with this Paul?

'A pound of rubber is worth a Ton of engineering.'- Jim Endruweit quoting Colin Chapman.

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