How about condenser failure when its getting warm, although I do agree some sort of fuel starvation does seem the most likely cause.
Misc: Everything Else Starts, runs then slowly "chokes up"
- Thread starter doctired
- Start date
One more thing that I haven't seen mentioned yet, make sure the choke lever isn't slowly moving when underway.
Plugs black, but air valves wide open to run.
Cap vents clear... plugs black, air valves wide open when running.
Orright, then. What slides, needle position, main jet, pilot jet and do the needles and seats seal properly and at the right height? Are the carburettors standard size?
When the engine loses power, I'd suggest applying the choke to see if things change. If there's a brief improvement it would suggest lack of fuel. I can't think of a way this problem would be produced by too much fuel, so it's either a fuel shortage or some sort of ignition problem, since we can assume that Maughn's did an excellent job on the engine itself.
You say you have a "D" ignition setup. In that case, you have a car-type coil. What's the age of that? Once hot, an old or abused coil can misbehave as you describe. One kind of abuse that can break down the internal insulation of a coil is running the engine or allowing it to spark with the plug(s) disconnected, causing internal sparking in the secondary windings.
Gary
You say you have a "D" ignition setup. In that case, you have a car-type coil. What's the age of that? Once hot, an old or abused coil can misbehave as you describe. One kind of abuse that can break down the internal insulation of a coil is running the engine or allowing it to spark with the plug(s) disconnected, causing internal sparking in the secondary windings.
Gary
Some rubber/ Plastic pipes, Are bad with the new petrol, Check the flow at the carb' end ?.
I had one go hard and snap off, Going into a mini roundabout, Wondered why I was riding speedway style !.
You have the monobloc filter In the top carb' fitting, I have never liked, I always cut them off, And just leave the washer.
Do you have to renew the Plugs, To do the next 20 miles ?.
I had to weaken my slides, Because of the new petrol, But I got a bad misfire, And had to stop, And change plugs, On my T.T. Carbs, I could do 10 or 20 miles, before trouble. Cheers Bill.
I had one go hard and snap off, Going into a mini roundabout, Wondered why I was riding speedway style !.
You have the monobloc filter In the top carb' fitting, I have never liked, I always cut them off, And just leave the washer.
Do you have to renew the Plugs, To do the next 20 miles ?.
I had to weaken my slides, Because of the new petrol, But I got a bad misfire, And had to stop, And change plugs, On my T.T. Carbs, I could do 10 or 20 miles, before trouble. Cheers Bill.
Do you have plastic floats in the monoblocs?
I had a similar problem though the bike did not stop completely. The plastic floats have /had,a slight ridge caused by the injection molding process which caused the float to jam in the down position on the casting for the float chamber cover screw at 7 o'clock. This resulted in flooding. I found out when I made a perspex cover to see what was going on. This happened on both new carbs on my twin and another member of our local mcc had the same issue on an Aerial. If it is this, carefully sanding the ridge off cures it. I did talk to Burlen about it but dont know if they did anything.
Mac
Mac
Engine fully rebuilt by Maughans 200 miles of careful running ago. Compression feels good.
Thanks, will check.