Bad running when hot

[XPXman]

My very old Maestro Special (137,000 miles) starts fine, runs really well until the engine is hot, the becomes very lumpy and won't tick over, cutting out when slowing down to a stop. Any suggestions appreciated.

[secubis3]

I had my special done at 120k. Same problems as yours. My garage stripped the carb down, cleaned the jets and found the float was sticking. They also changed the thermostat as it had only been changed once!!!!

So good servicing may also be required to help keep the old gal in good order.

Cheers
s

[G Force]

My very old Maestro Special (137,000 miles) starts fine, runs really well until the engine is hot, the becomes very lumpy and won't tick over, cutting out when slowing down to a stop. Any suggestions appreciated.

Check all the vacuum pipes and engine breather hoses for air leaks, the vacuum pipes have a tendancy perish over the years.

If you notice any significant oil leakage from around the rocker cover this will need attending to first, because this will also mean there is excess air entering the breathing system.

Check the distributor vacuum unit diaphragm is not punctured by connecting a suitable pipe and sucking on it. if you can't get the pipe to stick to your tounge the unit is faulty.

This time of year it is important that the hot air duct from the exhaust manifold shroud is connected properly to the air filter box.

If you don't find any air leaks then it is worth having the carb settings checked on an engine analyser.