AQ120B fault

[John Fones]

I have twin AQ120B engines, start perfect run for 20 mins then cut out and will not start again. Have run one engine at a time and enine 1 starts runs fo 20 mins cuts out. Engine 2 starts and does the same. Neither engine will start until cold again. I have fuel to the carbs and full sparks on all plus. Any one have any ideas? please help im getting desparate its nearly spring.

 

[el_pescador]

Hmmmm. Have you checked the obvious:

Adjustment of idle mixture and the idle speed?

Ignition timing?

Bad gas?

Water in the fuel?

Spark plugs properly gapped and in good condition?

Ignition wires in good condition?

Ignition coil in good condition?

Wiring to the coil in good condition?

And do you still have points and condenser in the distributors? If so, please consider installing an electronic ignition kit (I suggest Pertronix because of its reliability but there are other brands). You will notice a big difference.

That should be a start (pun intended)

 

[Jerryjerry05]

Profile? Location? Ethanol?? Check the tank for water? Check the tank vent hose?Tank pickup,clogged? Ethanol? The fuel lines get soft mushy and collapse. Doubt it but both coils going bad?? Check them? Too hot to touch? Ballast Resistors gone bad, again too hot?Measure voltage from one end to the other.12v in 9v out?