Fuel starvation.
Posted: Mon Jun 29, 2015 9:39 am
Rebuilt engine, carbs, fuel pump. Dellortos, glass bowl pump.
Filled carbs with fuel to start up.
Rev's suddenly dropped after a minute or so.
Problem traced to no fuel in front carb.
Checked banjo tee fitting, banjo filter, passage to needle valve, needle valve operation, float height and floats empty of fuel - no faults found.
Checked fuel flow with engine running - about .5ltr in 30 seconds or so. No way of checking pressure however.
Bypassed Filter King to eliminate problems there. No difference.
Before I remove the carbs again to get at the fuel pump, is there something else that might stop a carb filling?
It is strange that if it is a fuel delivery problem, only one carb is affected and that it's the front one which I'd have thought would receive any fuel first.
The Filter King remains only a quarter full so this may indicate lack of pressure.
I haven't yet checked the pump filter. It's also possible that the pump rebuild had a fault although it appeared to work satisfactorily when tested.
Any suggestions, other tests etc appreciated.
Dougal.
Filled carbs with fuel to start up.
Rev's suddenly dropped after a minute or so.
Problem traced to no fuel in front carb.
Checked banjo tee fitting, banjo filter, passage to needle valve, needle valve operation, float height and floats empty of fuel - no faults found.
Checked fuel flow with engine running - about .5ltr in 30 seconds or so. No way of checking pressure however.
Bypassed Filter King to eliminate problems there. No difference.
Before I remove the carbs again to get at the fuel pump, is there something else that might stop a carb filling?
It is strange that if it is a fuel delivery problem, only one carb is affected and that it's the front one which I'd have thought would receive any fuel first.
The Filter King remains only a quarter full so this may indicate lack of pressure.
I haven't yet checked the pump filter. It's also possible that the pump rebuild had a fault although it appeared to work satisfactorily when tested.
Any suggestions, other tests etc appreciated.
Dougal.