The Stovebolt Site Forums The Shop Area Engine Shop ignition problem, will start, run, then dies out both at idle & on the road

In reply to DLEE's question...........
No the air/fuel adjustment is only for fine tuning and will not effect the motor enough to soot up plugs.
Dirty plugs will aways come from severe over fuelling.
High float, sticking needle/seat, too high delivery pressure, wrong jetting in carby etc.
But it sounds like you must have a problem with your fuel lines/filter/tank etc. after reading your post Yippee ti iy ay.
If you bypassed all this and the engine is happy....at least now you know what you need to fix and replace.
As I said at the start of this saga......"Start with the simple things first and use the process of elimination until the problem is found".
"The cause will almost always be the smallest least expensive thing, but can cause the biggest headaches!"
all the best Doc Bob.