582 unexplainable stoppage

22 posts in this topic

Posted

I wanted to run something by the group as it has me stumped. After changing the gearbox from the B to the C it sat for a week or so while I completed a few more projects. I was out in the garage a week or so later and i turned the prop by hand and it came up solid. Like metal to metal solid. I backed the prop off a little bit and it was free again. I have rotated the gearbox now several times and it has never again done it again. 

Here is the work I have done prior to this happening. Gearbox change / new oil, removed one carburetor, milled in a vacuum port and installed the Hac system. Installed an air port in the air cleaner for the Hac., removed the intake manifold for paint and new gaskets, I did pull the front spark plug out during the gearbox swap. 

In my experience it felt gear related. 

I would appreciate your feedback. 

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Posted

Sounds like a foreign object in the gearbox. When you backed off the prop, it fell to the bottom. Otherwise, not a clue! But needs to be checked before running.

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Posted

Was something changed that might allow fuel to gravity feed through the carburetor or vacuum port if the engine was sitting in an intake port  open state? A cylinder full of gas cannot be compressed and would feel solid. Turning it backwards would move the liquid in the other direction and throw some of it out.

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Posted

Allen,  I agree. I’ll start with draining the gear box oil and check the plug and pulling all the spark plugs. If nothing is seen there I’ll split the gearbox again. 

Cloud, all the fuel was drained from the wings and both fuel selectors shit off from the time of left the hangar. 

 

 

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Posted

By "milled in a vacuum port" do you mean in the carburetor or in the intake manifold? I'm guessing it was done on a mill  and cleaned up before mounting back on the airplane? Would a metal chip that got left behind get sucked to the rotary intake valve and block it like a brick in a revolving door?

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Posted (edited)

Anything is possible but highly unlikely. I went through the carb and cleaned it out before reinstalling it. 

Edited by NorthIdahoAvidflyer

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Posted

Update: I pulled the spark plugs, gearbox and opened the carb slides and did a full inspection and several rotation of the engine. I ran a magnet through everything I could and used a mirror to look into everything possible. Everything looks as it should. I cleaned the gearbox out and reinstalled the halves. Someone had installed 3/16 lock washers on the hex head bolts that hold the gearbox halves together so i ran to the bolt store and bought 11 new 6M lock washers. Everything will go back together today with new oil and safety wire. I will post again after a test run hopefully this weekend. 

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Posted

That's pretty disconcerting! The only thing that seems plausible is something gearbox related. By intake manifold you mean the carb mounting plate over the rotary valve right? You might want to remove and inspect there again. the rotary valve could have bound up too causing the same symptom????

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Posted

No, I did not remove the mounting plate over the carbs. I opened the carb slides all the way and turned the engine over several times to check the rotary valve and edges. Everything looks good. I still feel it was gearbox related as I was very careful to make sure everything was covered and installed properly during the other updates. I will test run the engine and see how she sounds. I'll let you know how it works out. 

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Posted

I think it is possible that even a medium  sized grain of sand in between those gearbox gears could produce that which you describe.  Something so small that when you backed it up it went in with the oil and you'd likely not detect it when you opened it back up.

I really don't know, just tossing out ideas here but if it were something in the engine I think it would've have felt a little less "metal to metal" since you'd be working through the hardy disk rubber when you pulled the prop... it would have had a little give I'd think.

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Posted

Agree, This is what I and other have said too in relation to the hardi disk. The other checks were more to ease my suspicion more than anything. I feel very confident that it will be fine but a test run is the only thing that will determine that. I'll let you know.

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Posted

Is it possible that something fell into the PTO end of the engine while you were working?  Seems to me I remember a hole there where you can see the flywheel through.  I'll have to look at one of my 582s.  Something else to consider at any rate.  JImChuk

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Posted

Nothing is open into the engine. Once the Flywheel and Rubber Hardi Disk are installed the first half of the gearbox goes on and covers it. I have pulled that apart and it is clear. 

Thank you for the ideas.  

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Posted

I'm talking about the opposite end of the engine.  I believe there is a hole back there where you can see the flywheel.  Something falling in there could jam things perhaps.  Maybe I'll remember to look at my engine when I go back to the hangar after supper.  I'll get a pic then if my memory is correct.  JImChuk

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Posted

You wouldn't happen to have a GPL starter on that engine, would you?

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Posted

I'd feel much better flying behind that engine here in Iowa than in Idaho. No corn fields, no bean fields just one big pasture to land in as far as you can see in all directions and mostly flat. Spring is a great time to test an airplane back here. Until you get some mileage on it that uneasy feeling is not going to go away. Good Luck...

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Posted

Welll im not sure the brand but it said come out the back of the engine and extends through the firewall

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Posted

That's not a GPL starter then, they go off at 90 degrees to the crankshaft.  Here is the hole I'm referring to.  Probably should have a rubber plug in it or something, but it would be open by the starter gear anyway.  JImChuk

 

rotax 2.jpg

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Posted

Jim, That hole exposes the magneto flywheel and damper for inspection. The parts diagram doesn't show any plug for it.

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Posted

Thanks Nick for looking.  I didn't remember there being a plug for that hole.  Maybe would make sense though.   But I guess Rotax expected the engine to run plugs up.  It is a perfect place for something to fall into though

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Posted

Vance, is it possible that a piece of ash flaked off the head or piston top and wedged its way sideways between the two?  Maybe that would just crunch!  Maybe a spin with plugs out would cause it to show itself, if you don't have a borescope.

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Posted

Turbo, Yes this is a possibility. I had the exhaust manifold off and used the rope trick to re-torque the flywheel. It could have very easily knocked a small chunk loose.

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