I have Van's primer set up with lines going to two cylinders. For the second time and in a different place, I found the .125 copper line fractured. These lines are well supported. TT 85 hours.
Think I will change to SS.
Tim
+ 1 with Kyle, only difference... I never installed a primer system.
Yeesh. One airbox fire coming right up. If the prop isn't spinning, the fuel isn't going into the engine.Three pumps of the throttle before start...
I just pulled my primer system out a couple weeks ago for the same reason. Cracked copper line.
I need to learn the proper way to start an engine with the accelerator pump. I really, really don't want to start a fire with an airbox full of fuel. Can anyone enlighten me regarding the best method to safely start without a primer, especially in regions where it actually gets cold?
Yeesh. One airbox fire coming right up. If the prop isn't spinning, the fuel isn't going into the engine.
... starting procedure is to give the throttle two pumps while running the starter, wait about two blades, and turn the impulse mag to "on"....
I had an air box fire on a O-200 cold start because I pumped the throttle without the prop turning and had a backfire. It was after several failed start attempts which probably helped my chances of a fire. Post air box fire I only pump the throttle while the prop is turning.
Yes, repeated pumping of the throttle before the engine is running will create a considerable puddle of fuel and increase the odds of something bad happening.
We all have a drain hole in our airbox, right?
Me too! Same drill, two accelerator pumps immediately before cranking; 3 if it's below 35*F. 30 years on the O-320 without a primer. If you take the airbox off and have someone pump the throttle you'll see it takes a few seconds for gas to begin dribbling from the carb throat.Guess I've been lucky....for fourteen years its been one or two shots of throttle immediately followed by hitting the starter button (that's for a cold start, hot start doesn't need any help). No fires. I've never had a primer on my O-320.
If you take the airbox off and have someone pump the throttle you'll see it takes a few seconds for gas to begin dribbling from the carb throat.
deek
.......Heat your copper lines to red hot and let slow cool?
Yes, but remember gasoline will not burn. It's the vapors. And the vapors don't drain. Even with the fuel drained from the air box, there is still a very real potential for fire.
Not true! When presented with a flame gasoline burns just like ligter fluid. It's true that only vapor can ignite from a spark/ignition source. However gasoline burns quite nicely when lit by a flame. Ever watch a car fire?
Actually, it is the vapor that is burning. Example. Fill a quart milk bottle with gasoline, right to the top. Then make sure the outside is free of wetted area (no vapors , then take it to an area 30 ft from anything you don't want burned. Then take a match and light the top. It will burn the vapors coming off the liquid surface. A nice small flame. As the level burns down, and the liquid is heated, it will soon boil, then you have a roaring flame, but it is still the vapor that is combining with oxygen to burn, the liquid is still sitting down there in the container, just a reservoir. I had fun doing this test. It is not for the faint of heart. It could be hazardous to your future if handled poorly. Proceed at your own risk. etc etc.
To the topic - copper can live nicely if properly brazed/soldered and fastened to avoid vibration that will harden and fail the material. The focus should be on the attachment points. Not the material.
My earlier question was whether any of the pundits here can suggest an alternative material?