QuestionI recently purchased a MGB with 63000 mile that was parked in storage for 6-7 years. After driving it 25 miles, two cylinders (1 & 2) are fouling the plugs/ not firing and the exhaust is blue. I suspect stuck rings. Any ways to free them or is it rebuild time?
AnswerHi Fred.
Because both cylinders 1 and 2 are affected, I wonder if it is the rings. If you have a UK spec engine with twin SU carburetters, then I suspect that the float valve has stuck open on the front carb, and it is flooding the engine. Clean the valve and the problem should go away.
If you have a USA spec car with a single carb, then you may be right.
I have had two cars with stuck rings in the past. In both cases, they responded well to the following treatment.
Take out all 4 spark plugs and pour upper cylinder lubricant into the holes. (Redex in the UK). Do not use rust releasing fluid, because it would contaminate the oil in the sump and ruin the crankshaft bearings.
You need about half an egg cup of UCL in each cylinder. Turn the engine over slowly by hand a couple of turns, and then leave the engine for 24 hours.
Put the plugs back in after cleaning and checking the gaps.
Now start the car. This will create a dense white fog from the exhaust, so don't do this on the driveway on a Sunday morning.
With luck , the piston rings will free up over the next few miles, and you will have avoided the need for a strip down.
After all this, I would flush the engine with flushing oil, following the instructions on the can, and then fill up with a good 20W/50 mineral oil. Good Luck.
