Carbs running empty

[kwagga77]

Hallo all

 

We have a snag on a Rotax 582

 

it will run smooth for 3 or 5 hours,then just before take of when i want to take power for the take of roll,the engine would die on me.

 

when i inspect the Bing 54 carb bowls ,i would see that one of the bowls are empty.

 

does anybody have a remedy for this?

 

the engine is fitted to a weight shift microlight.

 

 

[turboplanner]

When you apply takeoff power, fuel demand by the carbs goes up by a huge amount.

 

You can make up a simple test rig consisting of a container suspended for gravity feed through a length of plastic tube.

 

First unscrew the drain on one of the bowls and connect the plastic to that bowl's inlet barb.

 

Time how long it takes to pass into a measuring jug until it reaches 1 litre

 

Then go upstream to the next item in the fuel line (maybe in-line filter, and see how long that takes to pass a litre

 

Then upstream again, testing the taps etc and finally the tank outlet.

 

It sounds as is there is a restriction at some point.

 

 

[Guest Andys@coffs]

on most weightshift the fuel tank is below the engine and a mikuni (sp?) or equivalent fuel pump that runs on crankcase pressure pulses lifts fuel up to the carbs. so testing such a system is difficult if the engine isn't running.

 

The fact that one is empty and one isn't may be hiding the fact that the mikuni pump needs a refurb seal kit put through to lift the overall volume of fuel delivered. As I recall the mikuni pumps used on 582's have one fuel inlet and 2 separate outputs for the dual carbs so it is very possible for the failure to be single carb related. if it was pulse related then no fuel in either, if valve (and again from memory just a rubber flap in a gasket.....) then very much single carb related

 

Andy

 

 

[Patrick Normoyle]

I'd try a new pulse pump or borrow one from a mate, test it in your machine, if no problems then your good, did you mean it will run smooth for 3 - 5 MINUTES not hours, and then die, try installing a second pump in parallel to the pulse pump, you can get them from an auto parts store, 12 volt and 3-5 psi, use it on take off and landing for extra insurance.

 

 

[SDQDI]

I'd try a new pulse pump or borrow one from a mate, test it in your machine, if no problems then your good, did you mean it will run smooth for 3 - 5 MINUTES not hours, and then die, try installing a second pump in parallel to the pulse pump, you can get them from an auto parts store, 12 volt and 3-5 psi, use it on take off and landing for extra insurance.

I've been trying to hold it in Pat, I was going to say if it was running dry after 3-5 hours maybe the tank was empty:sorry:

I was surprised that I held it back for so long.