"Engine Problems" Solved !

[VictorBravo]

Re: "Engine Problems" Solved !

IM wondering if i need to use the fuel shut off after flying . was told just turn the mags off mine acts like yours sometimes just not has bad . i have a 40 bc65 i shut the fuel off after shut down is this wrong ? thanks billy mcfarland

In my opinion, ALWAYS shut the fuel off after shutdown. The reasons include everything from not leaking $4 or $5/gallon avgas onto the ground to preventing a fire hazard.

I cannot think of any reason, other than the owner being lazy, not to shut off the fuel.

[flymac]

Re: "Engine Problems" Solved !

IM shuting the fuel off after....... I like to know if we are supose to shut it off with fuel cut off till the carb bowl empties and stops running . yes i allways cut the fuel off after after .........

[Pearson]

Re: "Engine Problems" Solved !

Bill,

There have been a lot of great suggestions for solving your engine quiting problem. I would like to offer a couple more.

Have you checked your airbox to verify that the carb heat is working properly? The reason I ask is I heard of a situation where the plate that actually moves when you turn on the carb heat came loose inside the airbox. It was partially blocking the airway when in the off position and would open up when the carb heat was pulled on.

The other thing I was thinking was to borrow another carb from someone's plane that is running correctly. If the problem goes away, you know it is in the carb and not a head pressure problem.

[Len Petterson]

Re: "Engine Problems" Solved !

I shut down the fuel let her run 15 sec or so when I kill the mags.
Just seams to start easyer next time. In the summer it works.
In the winter I dont think it matters but I allways shut the fuel off.
I use MMO in the fuel when I have it. We have too go to Niagara Fall NY for it, not sold in Canada anymore as far as I know.
saves the fuel system, I been told. I have used a small amount (1/2 Cup in a full tank)of 2 stroke oil for the same reason.
Bill is your engine still dieing on you, my freind with the Thorp, what have a mufflersystem on it, had a internal end baffel plow off ( end up looking eggshaped) and sometime plugging the outlet inside the muffler. The engine never totaly quit on him but last power on takeoff 300 400rpm
Is there anything what can plugg up you exhuast system for any reason, HAVE YOU HADE ANY BACK FIRE, MY FRIEND DID.
Len

[Gary Snell]

Re: "Engine Problems" Solved !

I still wouldn't rule out the fuel flow/lean condition. Same thing was happening to me right after the rebuild. It was only during steep climb and low fuel that it cut out which in my mind translated to fuel starvation when head pressure was reduced. I did two things. I replaced the carb seat since the needle travel didn't meet spec. It needs to have more travel on a gravity system than on a pumped system as specified in the Stromberg manual. Assume your mechanic checked that. I also replaced the metal fuel line from tank to gascolator which had an ever so slight barely perceptible kink. One or a combination of the two things I did worked. The carb heat thing doesn't make sense to me unless it is simply enrichening and otherwise lean condition. Do you have varnish buildup in the gascolator screen? That fine mesh screen is typically where the biggest pressure drop is in the system.

[N96337]

Re: "Engine Problems" Solved !

Bill, did your mechanic physically measure the venturi diameter and jet diameters? That would be where I'd be really suspicious now. From my memory, you should have a 1 3/8" venturi and a #45 main jet...but I'd definately check the parts book and make darned sure...if those were mismarked or not the correct part for this engine (which has happened lots of times to lots of people) you'd be running lean... thus an application of carb heat would in effect, fatten the mixture and make the engine happy for a while. I also set my carbs up, float level wise at minimum head pressure first, to make sure everything is going to work correctly there.... seems to make a difference sometimes...the engine type certificate will specify head pressure for carb settings...both for pump and gravity systems.
John