allan Posted January 23, 2005 Report Share Posted January 23, 2005 I have a standard DHC with a 2L engine. I am considering having the carb overhauled before getting back on the road in spring. Has anyone had this carried out by a specialist company recently? Is it worth doing? and how much did it cost? Also, can anyone recommend a carb specialist that likes TR 7s?!!! Alan. Quote Link to post Share on other sites
malcolm Posted January 23, 2005 Report Share Posted January 23, 2005 Alan. They are SUs so anyone involved in BL/Triumph/MG cars will be familiar. And yes it is worth doing if they have been in use for 20+ years. Even a small leak or sticking piston will matter. Also get the same specialist to set them up for you. Nicely balanced SUs make all the difference. Malcolm. Quote Link to post Share on other sites
allan Posted January 24, 2005 Author Report Share Posted January 24, 2005 Thanks for the reply Malcolm. Yes, I have felt something "sticking" when accelerating and have been unable to locate the problem. I have greased the throttle cable and lubricated the carb linkage to no avail. With the computer age applied to modern cars, it's probably more difficult now to find someone who can tune an older carb by touch and sound! Thanks Alan. Quote Link to post Share on other sites
Ian Mould Posted January 27, 2005 Report Share Posted January 27, 2005 When I first had my 7, one of the air pistons was stuck in a "down" position so I was effectively running on one carb. Taking the body off to free up and wiping some engine oil inside, reassembling and topping up the dash pot oil cured that. Later I found that the float chamber was full of flaking rust (from the tank I assume which had been replaced by the previous owner). This was doing nothing for the mixture control! I suggest it's worth dismantling in the first instance and cleaning out. You will probably find a local garage with an ageing proprieter who can tune the carbs but's its worth having a play yourself - thats what having these old cars is about. Quote Link to post Share on other sites
allan Posted January 27, 2005 Author Report Share Posted January 27, 2005 Sounds like a good suggestion Ian and of course it fairly simple to do. I suppose I could buy a kit to renovate the carbs but its the tuning that frightens me! Thanks, Alan. PS. Is it standard engine oil that is used to top up the dash pots? Quote Link to post Share on other sites
Rhodri Posted January 27, 2005 Report Share Posted January 27, 2005 Allan- Try Andrew Turner, an excellent bloke, was at the International, on www.su-carbs.co.uk . He is good for parts, advice, or the job done. Quote Link to post Share on other sites
Guest pimento76 Posted January 28, 2005 Report Share Posted January 28, 2005 I would agree with Ian Have a go yourself. SUs are fairly simple once you have taken them apart. I refurbished mine with very little knowledge of the workings, so i took photos with my digi camera at various stages in case I got lost ! If u have got a Haynes manual its pretty good on carbs. Tuning them is simple - its trial and error on the mixture and a piece of hose for balancing them. Worth checking the state of the needles for wear AND that they are the correct ones, I couldnt understand why my car ran rich no matter how much I turned the mixture screw,- needles were the wrong size !! I use standard 20/50 oil for the dashpots Alan Quote Link to post Share on other sites
allan Posted January 29, 2005 Author Report Share Posted January 29, 2005 Thanks Rhodri and Alan. Yes I am going to start on the carbs this weekend. A good tip is to use a digi camera to "feel" my way through and keep my confidence up! I intend to fit K&Ns when I finish but read in the Rimmers parts book that a standard set of Stromborgs will need different jets if K&Ns are fitted....anyone know whether this is needed? Thanks to all. Alan. Quote Link to post Share on other sites
rayjones Posted January 29, 2005 Report Share Posted January 29, 2005 Certainly S U's need different needles with K & N's ,fitted, as I found out. I imagine Strombergs will at least need some alteration too. Ra Quote Link to post Share on other sites
Ian Mould Posted February 1, 2005 Report Share Posted February 1, 2005 One small thing that might help. When you are balancing the carbs the usual way is to listen to the rush of air with a section of pipe, but with the air box off you can actually see the air pistons rise and decend together as you operate the throttle. This gets your adjustment in the right ball park before you need to trust your ears! I tried measuring the height of the piston for comparison with a steel rule but when you do this you obstruct the air flow so its a visual thing only. Good luck Quote Link to post Share on other sites
allan Posted February 2, 2005 Author Report Share Posted February 2, 2005 I have started on the carbs and so far so good..! In the mean time I have just had a quote for an overhaul (I asked for this before deciding to do it myself) which was £125 per carb....yes, thats a total of £250 plus postage.....now, where did I put those carbs....... Quote Link to post Share on other sites
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