brian
Well Known Member
My plane has no fuel priming system. Apparently no one in over 20 years has ever felt the need for one. I give it a pump or 2 with the throttle depending on how cold it is, none if the engine is warm. It generally starts just fine for me.
OTOH, a couple times I've had to cancel a flight because it simply wouldn't start or even fire. One time, there was lots of gas on the ground, but it wouldn't even fire. In these cases. I try until the battery is too weak, then I just push it back in the hangar, put the battery charger on it, and try it again next time.
At my last annual, the A&P mentioned I have no priming system, and said it must be hard to start. I told him about pumping the throttle, but he said the vast majority of any gas I pump that way just falls down into the air filter. True - I hadn't thought of that; with the carb upside down on the bottom of the engine. So that technique isn't amounting to much. He said in case of any backfire, it will also start a fire. He said I really should have a priming system that uses the priming ports provided by Lycoming.
So I ordered the Van's electric priming system. One thing I really liked about the idea of it was that all fuel stays forward of the firewall, rather than run back to a hand pump. It was also vastly cheaper than even a used priming system from/for a certificated plane.
http://vansaircraft.com/cgi-bin/store.cgi?ident=1492416080-132-612&browse=engines&product=eng-prime
I got it, but it came with next to nothing in the way of instructions; just a block diagram showing how it gets plumbed in from the gascolator.
Do any people on VAF have and use this system? The main question I have is how long to pump for. I assume I'd put a guarded momentary switch on it to activate the pump (interesting that the pump has a label on it that says it's for non-flammable liquids). But since there's no tactile feedback to using it, and no way to tell if I pumped too much or nothing at all, what are people with this system using to determine how long to hit the switch? What equals a "shot"? A full second? Half a second? Is it worthwhile to install it?
And does anyone have any installation tips or things to do or not do or things to watch out for?
Many thanks,
brian
OTOH, a couple times I've had to cancel a flight because it simply wouldn't start or even fire. One time, there was lots of gas on the ground, but it wouldn't even fire. In these cases. I try until the battery is too weak, then I just push it back in the hangar, put the battery charger on it, and try it again next time.
At my last annual, the A&P mentioned I have no priming system, and said it must be hard to start. I told him about pumping the throttle, but he said the vast majority of any gas I pump that way just falls down into the air filter. True - I hadn't thought of that; with the carb upside down on the bottom of the engine. So that technique isn't amounting to much. He said in case of any backfire, it will also start a fire. He said I really should have a priming system that uses the priming ports provided by Lycoming.
So I ordered the Van's electric priming system. One thing I really liked about the idea of it was that all fuel stays forward of the firewall, rather than run back to a hand pump. It was also vastly cheaper than even a used priming system from/for a certificated plane.
http://vansaircraft.com/cgi-bin/store.cgi?ident=1492416080-132-612&browse=engines&product=eng-prime
I got it, but it came with next to nothing in the way of instructions; just a block diagram showing how it gets plumbed in from the gascolator.
Do any people on VAF have and use this system? The main question I have is how long to pump for. I assume I'd put a guarded momentary switch on it to activate the pump (interesting that the pump has a label on it that says it's for non-flammable liquids). But since there's no tactile feedback to using it, and no way to tell if I pumped too much or nothing at all, what are people with this system using to determine how long to hit the switch? What equals a "shot"? A full second? Half a second? Is it worthwhile to install it?
And does anyone have any installation tips or things to do or not do or things to watch out for?
Many thanks,
brian