| Author | Message | ||
     KC - South Africa Unregistered guest Posted From: 168.209.98.67 |
Hi all My Shadow is a 1970 with SU carburetors (Serial no. SRH 8475) When I start the car fuel pours out of a pipe that seems to be the float chamber overflow. It is a metal pipe that runs from the float chamber down the back of the engine and over the bell housing. The fuel starts pouring out as soon as I turn on the ignition. What could be the problem? Can I repair it, or should I look for a SU specialist? I would appreciate your advice! KC | ||
| Richard Treacy Prolific User Username: richard_treacy Post Number: 62 Registered: 4-2003 |
You simply have a sticky float valve or worn mechanism. Repair is simple. Best would be to replace both floats, valve needles and seats. Also replace the float gaskets and the o-rings on the float retaining nuts. Parts are easily available from most tuning shops and are cheap. Simply remove the fuel and overflow pipes and remove the bolt at the centre of the float chamber, lift the lod off and presto. RT. | ||
| KC - South Africa Unregistered guest Posted From: 168.209.98.67 |
Thank you very much Richard. Is it a simple remove and replace job, or are there complicated settings? I have never worked on carburetors, but would like to do it myself if I can. Regards KC | ||
| Richard Treacy Prolific User Username: richard_treacy Post Number: 63 Registered: 4-2003 |
I can send you a diagramme of the float level setting if you give me an e-mail address. There is absolutely nothing complicated, and no special tools are required. It is a common feature of all SU equipped cars to leak like this, but the floats usually settle down after starting or just by knocking the float chamber with a piece of wood. Earlier cars had a tickler which would stop the leak after a short push. RT. | ||
| KC - South Africa Unregistered guest Posted From: 168.209.98.67 |
Thank you very much! I would appreciate the diagramme. My e-mail address is kcandjen@mweb.co.za I really enjoy working on the car myself, and appreciate any opportunity to learn more. Regards KC | ||
| KC - South Africa Unregistered guest Posted From: 168.210.90.232 |
I have ordered new needle and seats, as well as floats. I hope that I ordered the correct parts! After searching various websites, asking the dealers and looking at the carburettors no-one seems sure as to which parts to order. Rolls-Royce used several different SU carburettors trough the years. They quote one number for the 6230cc engine up to 1969, and another for the 6750cc engine from 1970 onwards. Mine is a 1970 6230, so which of the two do I have?! The little silver plate indicating the part number is missing…as usual. Now for a question. I opened both float chambers, and found that I have two different floats. They are both the same height, but the one has a smaller diameter. The one is a snug fit, with about 3mm between the float side and the inner wall of the float chamber. The other has about 8mm between the float side and the inner wall of the float chamber. Which is correct? The parts will hopefully arrive on Wednesday. Regards KC | ||
| Jim Bettison Unregistered guest Posted From: 203.166.107.242 |
I have been away for several days, and I hope that this info is not too late for you. SU and Zenith carburettors, and spares for same, are now made in UK by a company by the name of Burlen. Find them at www.burlen.co.ok I have used them for several parts and literature purchases. Their service has been immaculate (I have no financial connections with them!!!). Not cheap, but not expensive if you want to get it right first time. Burlen are the lineal descendants of Skinner Union (SU) via several acquisitions, etc, and you can be sure that what you are getting is what was originally supplied. I suggest you contact them and see if they can assist. I would be very glad to hear how you get on. Good luck, Jim Bettison. PS: I am in Australia. | ||
| Bill Coburn Prolific User Username: bill_coburn Post Number: 61 Registered: 4-2003 |
Jim Love to collect such websites but this one for some reason didn't work. Can you confirm pls. While we are about it is there a web site for the K Jetronic fuel injection system - I am being drawn inexorably into that world against my better judgement. | ||
| David Gore Moderator Username: david_gore Post Number: 123 Registered: 4-2003 |
Bill/Jim, There is a typo in the link - the correct link is as below: http://www.burlen.co.uk/ Bill, if you are serious about getting into the intricacies of the Fuel injection system; you will need to purchase a diagnostic unit to tap into the control system to read the sensor information - these are not cheap unless you can purchase one second-hand from a bankruptcy auction or similar. See the posts on engine power loss under Silver Spirit, Spur and later cars in this forum. On your next trip to Sydney, I suggest you visit Mainline Auto at Kingsgrove who distribute these items [and car hoists as well] - they were very helpful when I saw them to get information for this topic. The link below is an example of what you need: http://www.mainlineauto.com.au/products/electrajet/index.htm#electraspec | ||
| Bill Coburn Prolific User Username: bill_coburn Post Number: 62 Registered: 4-2003 |
Relax David. I love to watch surgical procedures but I have no ambition to slice into my mates although there are some I would like to practice on! Seriously I feel very uncomfortable when I don't have SOME idea of what a system is doing. As you know I recently went through some anxiety with a hot hard starting '87 Spirit. The previous owner (unknown)must have used the starter as a percussive instrument to accompany his screams of rage when the rotten thing would not start. These cars were the first to use the lovely little Nippondenso starter which is very very reliable with their one Achilles heel being the main contacts. Anyway having sorted out the hot starting problem the starter expired. New points and a good cleanout and all is well. As embarrassing as all this was I now have a better understanding of ONE of the fuel injection system fail areas and hopefully can get the car to my injection man before it wrecks starters or foreign lightning strikes it. We have a mutual friend down South who has one of these cars that keeps losing fuel pressure and he has spent months trying to find the leak!! I think it will be a very long while before we rip one of these sytems apart at a self help group. Thanks for the web site, that was fascinating. Cheers and see you tomorrow at Goulburn. | ||
| KC - South Africa Unregistered guest Posted From: 168.209.98.67 |
Thank you to everyone for the advice offered on my fuel overflow problem. I replaced the needle and seats, as well as the floats. One of the floats was full of fuel, so that was the problem. Regards KC |
