SLROC Forum

Not yet, been waiting on fuel pump and a few bits for the carbs being delivered, hopefully turned up today.

Jack

Just an update, seems to be running alright now, new fuel pump is much better.

Unfortunately I still have one problem, Tuning the carbs, one of them always seems to be running lean.

Interestingly the ID tags on them have completely different numbers, Can't quite remember at the moment but one is 3xxx and the other 4xxx as far as I'm aware they should both have the same number and it should be 3xxx as it's a pre '86 non-detoxed engine. I think further investigation is needed. Or SU's...

I've also head that running lean can cause overheating problems, is that true?

Jack

Don't bother with SU's, nice in a little light sports car but they do not hold tune as well as Strombergs and are much more on/off with the power delivery.

Are both carbs the same size? (should be 175CD). Both needles lifting correctly?

You need a carb balancer to get them both drawing the same amount of air first then tune the mixture (with the balance bar off)

Yes running lean will make the combustion temp higher and will melt pistons.

Everyone else I've ever talked to seems to be of the opinion that SU's are much better. I Don't have much experience with them but think the strombergs look better and I already have them so they'll be staying anyway.

Aye, they are both 175s and needles are lifting correctly. airflow is fairly well balanced but I'll double check tomorrow when I have time.

ID tag of one is 4185 which (from the info on rimmer bros) corresponds to a post '86 non-detox range rover

tag seems to have fallen off of the other one I'm sure I've got it noted down somewhere.

I'm thinking a previous owner purchased 2 matching needles which would be right for the possibly original carb but the profile is wrong for the later (possibly stolen from a RR) one that is constantly running lean.

Its a myth that SU's are better. Many of the people who think they are either incapable of tuning a Stromberg through laziness or have such a worn out Strommy that anything would fuel the engine more competantly.
Put it this way a Stromberg will run with no dashpot oil, an SU will refuse to run. Yes if the diaphragm splits on a Stromberg they will not run either but service them at the correct intervals with a quality part and they are completely trouble free. A spare diaphragm is only pence anyway!

I'm not 100% sure on the needle sizing query, you could be on the right lines though.

Are both needles winding in and out properly? As a rough guide mine runs happily at about 2.75 turns ACW from fully locked at clockwise.