gs 650 gt 1983

[stony]

AT MY WITS END. The bike was on a spin and covered 120 miles, running like a clock. Suddenly a gradual loss of power and a cut out. Refused to start. Got her home. Checked ignition, sparking on all 4. Fuel in fuel filter under tank, tank not air locking. Bike started but only revving to 4000rpm, completely flat after that. Bike will rev fully when aerosol sprayed into manifold, indicating fuel starvation.Tried an alternative fuel supply, no change. Removed carbs, found nothing, cleaned and blew out, just in case. Refitted and problem still there.
ANY IDEAS??????????

[Don-lo]

Did you look at the spark plugs? It's possible that a float stuck and you fouled out a plug. If so, replace the plugs and check your oil for a gassy smell.

Otherwise, your symptoms sound like a fuel delivery problem. Did you switch to "reserve" just before the problems started? Try removing the fuel filter.

When replacing the carbs on a 650, I loosen the battery box too to get a little extra room.