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MG MGB Technical - clogged carb... need help.

I have the SU carbs and am in the process of getting the car running. The left carb (standing facing the drivers side of the engine) seems to be clean, and that fuel floater bowl over there is perfectly clean. The right carb on the other hand has a gooey oil like substance in it and the floater is full of fuel (even after not being run for about 6 years). Clogged floater line? (the bottome one?) also... what is this substance in the carb, and do I just clean it with carb cleaner or what? Also... how do I get the WHOLE carb assembly off? not just the caps and whatnot? Is there a way to take both off the head?
Bryan Corey

Brian, spend 10-15 bucks and buy yourself a Haynes- it shows and tells in simple language- available at any auto parts store.
Read the section, try to do it, then write back and ask for help if you need it. You cannot go wrong if you use the Haynes manual for this job.
Ken R
Ken Rich

Not a very generous response from Ken.

Hopefully there will be one or two enthusiasts who have done this little job before who can help Bryan out.

I would but I don't know how.
Dick

Bryan,
I assume you already have removed the air filters and the choke cable anchor is loose. Disconnect the fuel lines and lay them aside. Disconnect the throttle return springs. There should be three springs. There are two 5/16" nuts (1/2" wrench) securing the carbs to the manifold. Remove those nuts and slide the carbs and heat shield off the studs until the carbs clear the studs. The heat shield can stay on the studs for now. Take careful note of how the linkages are asseblemed between the carbs. As the carbs clear the stud, move them apart slightly and the linkages will disengage the carbs. Leave the linkages on their cables in the engine compartment. You should now have two carbs loose ready to be worked on. I would work on one carb at a time so you have a whole one as a pattern. Remove the dome and piston. Remove the float bowl cover. Empty the float bowl and clean with aerosol carb cleaner. Use the cleaner plastic pipe to spray cleaner through the hose from the bottom of the bowl to the metering jet in the bottom of the throttle bore. Spray cleaning through that line both directions until clean. If you can't get the line clean or if it leaks, you will need to replace it. Also check the metering jet hole, it must round, if it is worn out of round, replace them. Remove the float from the float bowl cover. Remove the fuel control jet from the float cover and clean it and the fuel passage and vent passage with the aerosol carb cleaner. Reassemble in reverse order. Replace the fuel filter and run about a quart of fuel through the new filter and lines to the carbs into a clean container before reinstalling the carbs. If the fuel is clean, put it back in the fuel tank. If the fuel is not clean, discard (properly) and repeat until you get clean fuel.
The lastest issue of 'Grassroots Motorsports' has a very nice article on SUs.
Leland Bradley

Is the article on SUs in 'Grassroots Motorsports' online anywhere.
Dick

Dick,

As a frequent poster on this BBS, I must say I agree with Ken's response. There are a great many questions posted here which could be easily answered by reading the appropriate reference, or even by looking in the archives. I understand that someone new to this board may not even know about the archives or how to use them. But I think it should be a basic rule of thumb that someone has at least looked at the reference material first. It takes a good deal of thought and time to respond to a technical question, and none of us are getting paid to do it. If the explanations in the manual are unclear, or if someone is unfamiliar with translating British English to American English, there are a great many people here willing to help with clear, concise, technical help. Bob Munch, Paul Hunt, Daniel Wong and many many others have excellent tips based on their experience. I think this forum is most effectively used when the initial poster has at least attempted to find for themselves some information. We understand that the newbies out there are starting from scratch, and suggesting that Bryan purchase a Haynes manual first is a good place to start. It will help him be able to perform the basic services needed to keep his car going.
Paul Konkle

I really was not attempting to be un-generous, or rude, it is just that the Haynes gives a clear description of this process, and the workshop drawings label all the parts that Leland names in his clear description. Leland can probably pull SU's in his sleep, he has done it so many times. Bryan cannot, and needs to see what Leland is describing. That is the importance of the manual and its drawings and photos. I think it is a simple process too, but then I have done it more than a few times. I can remember approaching it with not a little trepidation first time, and I had the official workshop manual.
Ken R
Ken Rich

This thread was discussed between 24/04/2002 and 25/04/2002

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