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First starts and prop cycling

jwilbur

Well Known Member
I did my second engine run today on my RV-10. First start a few days ago for 3 minutes. No issues. Ran today following the Lycoming manual for a fresh install. Basically warm up at 1000 RPM, run at 1500 RPM for 15 minutes while watching CHTs and pressures. Do a mag check and cycle the prop, Run up to full power for less than 10 seconds, pull back to idle, and shut down. Shut down if anything is out of the ordinary.

Thi is a new IO-540-D4A5 and new 2 blade Hartzell - stock right from Van's. All went well in everything except the prop doesn't cycle.

At about the 10 minute mark running at 1500 I tried several times and nothing. Then I ran up to 2200 and tried again. Nothing. Back to 1500. Tried again. Nothing. Back up to 2200 again and still nothing. I aborted the test at this point, not going the full 15 minutes. Backed off to idle, then up to 1000 and shut down.

CHTs got up to 350. Oil and fuel pressure were in the green. Oil temp seemed a bit low for the whole test, only reaching 151* F.

Any suggestions on troubleshooting the prop cycling issue?
 
Stock engines from Vans used to come with a plug inside the crankshaft that has to be pulled out for a CS prop. Did you pull it?
What governor did you install? Any chance the gasket is covering an oil port?
 
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Should have searched first. Just found this old thread. Will try suggestions made here.

http://www.vansairforce.com/community/showthread.php?t=104336

My procedure was to pull the prop control and hold it for about 3 - 5 seconds. When nothing happened, I pushed it back in. If I'm reading correctly, I should be holding it out for a while longer to allow the oil to flow through.

Is this correct?

Correct. It might take 30 seconds to fill the crankshaft with oil.
BTW, some of the Hartzell governors really need 1700 rpm before they come off the stop.
 
Yes, the first time you run it the oil takes a while to fill the prop, so leave it back for a while while running at 1900-2000. You'll hear it catch.

Vic
 
Looks like it's a bigger problem. I let it run at 2200 for a full minute with the prop control pulled back. No RPM change. It's a Hartzell governor I got with the FWF kit from Van's. Stock engine and prop. I could use some advice.

I know the forward plug is out and the documentation I got with the engine says specifically if using a CS prop to remove the forward plug. It says nothing about the aft plug. I believe the aft plug was in place (if memory serves) and the docs certainly imply it's there.

I'm thinking the next step is to remove the governor and send it out for an inspection or maybe back to Van's if there's a warranty through them. Is there anything else I can do at this point to troubleshoot this issue?
 
Before I sent the governor off, I'd check the position of the gasket. Ocam's razor says that if you have a new prop and a new governor, they are probably fine. Which means installation is more likely the issue. Not certain - but more likely.
 
Before I sent the governor off, I'd check the position of the gasket. Ocam's razor says that if you have a new prop and a new governor, they are probably fine. Which means installation is more likely the issue. Not certain - but more likely.

I'll check the gasket when I remove governor. Hopefully you're right and I'll be able to just reinstall it.
 
A few more things to check from a trouble shooting perspective is to verify the blades actually move by manually moving them (if you haven't already) and to back the prop off the hub to see if oil drips out. Finally once you remove the PG make sure the shaft rotates freely by hand.
 
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A few more things to check from a trouble shooting perspective is to verify the blades actually move by manually moving them (if you haven't already) and to back the prop off the hub to see if oil drips out. Finally once you remove the PG make sure the shaft rotates freely by hand.

Thank you. I did move the blades manually today so I know that works. I'll be removing the PG tomorrow and possibly backing off the prop as you suggested.
 
bad governor

I took the governor off. The gasket/screen had been installed correctly. And there was plenty of oil in all the ports. I then successfully cycled the prop with compressed air pushed into the engine inlet oil port (the one the governor should be using). Didn't even take much pressure to do it.

I tried turning the governor shaft by hand. It turns easily backwards, but only with GREAT difficulty in the correct direction. Not sure if this means anything.

I got the governor with the FWF kit from Van's so I'm hoping they'll just swap it for me. Not sure what warranty there might be but we'll see. At this point I think everything is pointing at a bad governor.

Can anybody think of anything I might be missing?
 
To build on Paul's comment, also check to ensure the gasket has a filter screen on it rather than just a little hole or, even worse, being a solid gasket. The wrong gasket can block oil flow by simply not having an orifice through which oil can move. MS9144-01 is the proper gasket for 4-cylinder Lycoming engines - not sure if that's the correct one for 6-cylinder engines but suspect it is.
 
To build on Paul's comment, also check to ensure the gasket has a filter screen on it rather than just a little hole or, even worse, being a solid gasket. The wrong gasket can block oil flow by simply not having an orifice through which oil can move. MS9144-01 is the proper gasket for 4-cylinder Lycoming engines - not sure if that's the correct one for 6-cylinder engines but suspect it is.

Yep. It's the right one. Pretty sure it's a bad governor.
 
Solved.

Before I sent the governor off, I'd check the position of the gasket. Ocam's razor says that if you have a new prop and a new governor, they are probably fine. Which means installation is more likely the issue. Not certain - but more likely.

So. .... Occam's razor, huh? .... Turns out my Tach was lying to me because I had it calibrated for a 4 cylinder engine. When I thought I was running at 2200 RPM, I was really running ~1500 RPM. .... Fixed the calibration, put the PG back on the engine, ran it again, and cycled the prop without issue.

I ran across this thread on VAF, noted the symptoms were identical, wrote to him about his solution, and you know the rest.

http://www.vansairforce.com/community/showthread.php?t=141150

Thank you all for your input.
 
Glad you got it!
Something I do for all first engine starts, on new airplanes and after panel upgrades, is to have an optical, electronic tach on the glareshield. It's a very fast comparison of the panel-mounted tachometer.

Vic
 
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