• Become a Subscribing Member today!

    J3-Cub.com is the largest community of J3-Cub pilots, owners and enthusiasts. With over 1000 active members, we have fostered a vibrant community and extensive knowledge base.

    Access to the J3-Cub.com community is by subscription only. Membership is only $49.99/year or $6.99/month to gain access to this community and extensive unmatched library of knowledge.

    Why become a Subscribing Member?

    • J3-Cub.com hosts a library of over 13 years of technical discussions, J3 data, tutorials, plane builds, guides, technical manuals and more.
    • J3-Cub.com also hosts an extensive library of J3-Cub photos.
    • You will also receive two J3-Cub decals!

    Become a Subscribing Member and access J3-Cub.com in full!

    Subscribe Now

Starting and shutting down-basic engine questions

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

Evan

Well-Known Member
Supporting Member
Joined
Aug 26, 2019
Messages
241
Reaction score
72
It's my understanding that the priming knob pumps fuel directly into cylinders.
Turning the propeller , if the throttle is open a bit, will pull air and fuel into the cylinders, probably in a more-or-less stoichiometric ratio necessary for combustion. So why prime ? Is it necessary ? Or just more expedient ?

What is the best way to shut down an engine that has a mixture control ? It seems like shutting down with mixture control would be advantageous as it starves engine of fuel. So if mag switch stays hot, turning prop should not bring engine to life--as long as you turn off mags after engine has stopped.

Will pulling mixture to idle cutoff prevent fuel from leaking onto floor if carb float valve doesn't close all the way ?
 

Latest posts

Back
Top