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Discussion Starter #1
Hello all, during my search for a Shadow I ran into an older gentleman with a Silver Wraith II suffering from an extreme rich condition. Bogging down, rolling coal, failing to proceed, etc. All the classic symptoms of major fuel system troubles. Since he does not own a computer he has asked me to help him find a competent Rolls-Royce mechanic in the Calgary area. It would be preferable if he could come to the car as it is unlikely the car will make it to a shop unless it is in the inner city. I suspect the floats and needle valves have failed or are severely out of adjustment. Any help in this matter would be greatly appreciated!
 

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Might be worth checking the choke operation, choke cam may be sticking and just need a good clean and a very light oiling but put no oil on the cam face. Also, if the choke stove pipe or the choke spring are clogged it would delay or stop the disengagement of the choke. Also, there's a breather hose from the engine oil cap housing to the air intake between the carbs, there's a filter inside that pipe at the oil filler cap end at that may need a good clean out with carb cleaner so the engine can breathe freely. The pistons in the carb dashpots could be sticking due to lack of oil or the pistons may just need a good clean with lacquer thinner or denatured alcohol. Sorry I can't help with a mechanic as I'm not familiar with Calgary but if the problem has to do with the SU carbs or choke or breather mechanism any good old car mechanic should be able to diagnose it. SU HIF7 carb mixture settings are done at the SU factory during manufacture and a tamper-proof cover is placed over the screw to dissuade people from fiddling with it, to properly check the mixture exhaust gas analysing equipment is needed.
 

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First thing I would do is remove the air intake trunking and make sure the choke butterfly is opening when warm as mentioned above, a failure of that system will certainly cause heavy black smoke and stalling. A piece of wire on the choke butterfly lever on the passenger side of the choke housing pulling the lever up all the way will open the choke for testing purposes. If it is opening OK but still flooding out take the carbs off.
The float bowls are integral with the carb bodies on the SU HIF's fitted to Shadow II's so the carbs have to be removed from the engine to access the floats and needles and seats. Fortunately they come off very easily with just one central bolt holding the carbs and housing onto the manifold. They have plastic floats and needles with Viton tips which can fail with time so I would suspect they are the problem. The filter system is pretty good on these so unlikely dirt under the needles and seats. Any competent British car specialist shop can fix those carbs, try British Auto Specialists. Perhaps contact the local British car clubs for recommendations.
The spark plugs will definitely have to be pulled and blasted clean or replaced as they will be carbon fouled and will misfire like crazy.
Contact me offline and I will send you a couple other Rolls-Royce owner's email addresses in Calgary that can make mechanic recommendations.
 

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Discussion Starter #6
Thanks Jim, I will PM you shortly. British Auto Specialists claims they deal with SU carbs, but refused to work on Rolls-Royce.
 
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