I'm looking for a pony motor mag switch for a 4D7U (4F4784).  Many Thanks! Tom

No need for it, shut the gas valve off.

Hawkeye283 wrote:

I'm looking for a pony motor mag switch for a 4D7U (4F4784).  Many Thanks! Tom
 

Hi Tom,
What Hawkeye283 is referring to is the fact that when shutting down pony motors it is best to turn the gas off to the carburetor so it will drain the float bowl. If you turn off the mag switch the float bowl stays full the gas, and by design (vibration and siphon) the gas finds its way into the crankcase oil of the pony. Because pony motor don't have much oil reserve, a small amount of gas in the oil is kryptonite to pony motors. After the pony has run out of gas then one can turn off the mag switch. The mag switch grounds out the mag so there is no voltage draw if left on.
THEE number one killer of pony motors has been gas in the oil.
Good luck
 

Many thanks for the replies. I understand the fluid dynamics involved along with the lubricity of oil vs. the non-lubricity of fuel. As with the old radial engines I fly and work on you always use the idle cutoff to shut them down-in normal operation, but you have a mag switch to use if needed. My concern is if I need to shut the pony motor down in a hurry due to an issue I'd like the option of having a grounding switch. Plus it fills the hole up in the panel (LOL). Off subject but using AV gas in the pony motor doesn't varnish up the carb like auto fuel does, and it doesn't go sour as quickly.

I believe this is what you wanted.  Text (573-433-nine two seven seven) me your address, if you do texting, and I will send it to you.  I agree with you 100%.  In case of something going wrong at least you have an option and yes, it is suppose to be there. Brian Boaz