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Prop won't cycle, where to start troubleshooting?

agent4573

Well Known Member
Mods, feel free to move this to the right section, wasn't sure where to put it.

New Titan IO-370 from Aerosport Power (2 hours of engine run-in before it left the factory). New Whirlwind 300 CS prop. New PCU5000 governor. New Saber 2.5" CS adapter.

We've done our first few engine runs on the ground and everything looks good so far except that the prop won't cycle. I've got a total of 4 engine runs on it (short runs to keep the CHTs down on the ground). Today we had 180-200 degree oil, 90psi @2000 rpm and I've probably done 2 dozen cycles on it. It's probably 15 or so 3 counts where I pull the prop back and then cycle it forward, and then 5-10 longer cycles where I leave the prop back for 10-15 seconds before pushing it back forward. All total, there's probably over a minute of the prop pulled all the way back at 2000rpm.

There's zero rpm change so far. The blades appear to be slightly more coarse now after shutdown then when I first started, but something isn't right. During the longer cycles, manifold pressure will increase by about 1" when I pull the prop back and it will drop when I push it forward, but there's no RPM change.

Looking for next steps. Do I try it again at 2200 rpm? Do I just leave the prop all the way back until it does something? I installed the gasket so the screen was matched up to the recess in the governor body, but maybe I put the whole thing on upside down? It was clocked dam close to where it should have sat from the factory, governor spec sheet attached. Planning on calling aerosport, whirlwind and APS tomorrow but thought I would get your guys' ideas as well. Thanks.
 

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Some props, perhaps this one, have a smaller piston, therefore require a higher pressure governor. Most governors can be modified for increased pressure by adding washers under the relief spring just like the oil pressure relief valve. I suggest calling Wings West Governors in Puyallup, Washington, they are experts and most likely can give you a definitive answer, usually better than forum opinions!

Regards,

DAR Gary
 
Some props, perhaps this one, have a smaller piston, therefore require a higher pressure governor. Most governors can be modified for increased pressure by adding washers under the relief spring just like the oil pressure relief valve. I suggest calling Wings West Governors in Puyallup, Washington, they are experts and most likely can give you a definitive answer, usually better than forum opinions!

Regards,

DAR Gary

I'll be sure to ask about that tomorrow on the phone calls. Whirlwind recommends the Jihostroj governor for this prop, and from what I can tell, the PCU5000 and the Jihostroj are clones of each other. You are correct though, the relief pressure of the recommended governor is 460-490psi. It looks like the standard Jihostroj is rated at 310-330 psi.

EDIT: So Whirlwind's site has conflicting information. The website suggests 490psi, the propellor manual has a big warning that says 330 psi max. I'll get clarification tomorrow.
 
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I had the same issue with my Hartzell prop and governor on initial runs. The issue ended up being preservative grease in the oil line between the governor and the front of the engine. Removed both ends and used compressed air to blow the line out. Problem fixed. Not sure if your setup has an internal or external oil supply line but it’s worth a look.
 
Crank shaft plug?

On my Lycoming IO-320 I had to remove the plug from the hollow crank shaft. Is there a similar arrangement on your engine?

Good luck!
 
I had the same issue with my Hartzell prop and governor on initial runs. The issue ended up being preservative grease in the oil line between the governor and the front of the engine. Removed both ends and used compressed air to blow the line out. Problem fixed. Not sure if your setup has an internal or external oil supply line but it’s worth a look.

External line. I'll pull it off tomorrow and blow it out.

On my Lycoming IO-320 I had to remove the plug from the hollow crank shaft. Is there a similar arrangement on your engine?

Good luck!

I'll verify with Aerosport. They knew a CS prop was going on, so I assumed they ran it in with a CS prop. Nothing in any paperwork said I had to remove a plug, but I'll check for sure. Hopefully its that simple.
 
In addition to the suggestions above, one silly thing I have seen catch people in these days of electronic instrumentation is your Tach calibration. In other words, make sure that you are really turning the RPM that you think you are. Most EFIS’s have a setting in there to tell the computer how many pulses it should see for each revolution - make insure it is right. Then make sure that you are getting all the pulses that you should.

The best outside verification is an optical tach.

Since the engine and prop is new to you, you might not have a baseline for what the RPM should sound like - and generally speaking, most of our props need at least 1800 REAL rpm to cycle.

Just another thing to check….
 
M1B Hartzell, but my first cycle was after several engine runs and took probably a total of 1-2 minutes. Not to discount a real problem but just my experience.

Ironflight Tach +1 - - A 14 friend (RIP) had a tach error and was running higher actual RPM. Long time to get prop to cycle and when it did, it jumped the chocks and headed for . . . . many things. Brakes obviously had never been used in anger, so reminder to keep it tied for the test. A sudden 800 lb thrust must have surprised the chocks.

I'll verify with Aerosport. They knew a CS prop was going on, so I assumed they ran it in with a CS prop. Nothing in any paperwork said I had to remove a plug, but I'll check for sure. Hopefully its that simple.

They typically test with either a dyno or club prop. I would not assume that the plug was removed.
 
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My IO390 was test run but came with the crankshaft plug in place. It is easy to remove but will require removing the prop to access.
 
My IO390 was test run but came with the crankshaft plug in place. It is easy to remove but will require removing the prop to access.

I haven't confirmed with Aerosport yet, but this seems like the most likely cause. I'll be pulling the prop back off tonight.
 
My IO390 was test run but came with the crankshaft plug in place. It is easy to remove but will require removing the prop to access.

Yes, removing the plug was “easy” but hitting my brand new $35k engine with a 5 Pound hammer and sharp chisel was a bit nerve racking. One hit with the hammer and chisel and the plug deformed enough to pull it out with needle nose pliers.
 
Will it even cycle below 2,000 rpm? The props on my twin (IO-320's) won't. And looking back on the WW 151 I did on a RV-7 with a 320, it cycle at 2300 RPM, a little.

Just a thought.
 
Will it even cycle below 2,000 rpm? The props on my twin (IO-320's) won't. And looking back on the WW 151 I did on a RV-7 with a 320, it cycle at 2300 RPM, a little.

Just a thought.

I'm not sure. Per the prop manual:
"To ensure proper first run-up of your new Whirl Wind 300 Series propeller system, refer to your engine’s operation manual for the proper run-up power setting. At the proper run-up power setting pull the propeller control lever back until the RPM drops by 300 - 400 RPM."

Per the engine operation manual:
b. Propeller Governor Checkout
1) Throttle.................................................. 2000 RPM
CAUTION: Do not allow the engine RPM to drop below 1200 RPM
during propeller control checkout.
2) Propeller Governor ............................... Low RPM position
RESULT: Engine RPM decreases to minimum governing speed or as
specified by aircraft manufacturer.
3) Propeller Governor ............................... High RPM position
RESULT: Engine RPM returns to 2000 RPM. Cycle the Propeller

By Whirlwind deferring to the engine operating manual for run-up, they're endorsing a 2000 rpm propellor cycle. I would have hoped they tested it at various RPM before creating their prop manual and made sure it worked, otherwise a note would have been nice specifying a minimum RPM for prop cycle.

I spoke with Aerosport and they said they do run it on the test stand with a fixed pitch prop. They normally install the front plug for the test stand and then remove it before shipping for CS applications. He still suggested I remove the prop and double check that it didn't get left in accidentally.
 
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The guy from APS seemed convinced that it should cycle well below 2000 rpm. He also told me that being able to hit both the high and low speed stops on the governor was completely incorrect and that I needed to redo my rigging to prevent me from hitting the low speed stop. Not sure how the DAR is going to react when I tell him I can only hit one stop and it's intentional.

Darren from aerosport pulled my build record and said it should be setup for CS but to send him pics so he could verify they didn't accidentally leave the forward plug in place.

Anyway, pulled the prop. The crank was about half full of oil, and the prop had a few drops in it, didn't even need a bucket to catch the spilled oil. Blew out the line from the governor going forward and got a few drops of oil and then just air. With the line disconnected I pressurized the motor with the preoiler(40psi) and got a dribble of oil out of the governor.

I called whirlwind and explained the situation. Tech support took my name and number and said they'd look into and call me back in a few days. They were busy.

I'll reinstall everything tomorrow and plan on tying down to my truck this weekend for a full 2700 rpm runup and prop cycle. Not sure what else to try besides that. Hopefully I don't have to do that for every preflight in the future.
 

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Not sure what the range is on the PCU governor but my Hartzell governor won't cycle below 2000 rpm...

Just another data point - I have the MT Propeller P-860-4 with a Hartzell HC-C2YR-1BFP-F7497 and it cycles fine at 1700 RPM when I do my run-up.
 
Just another data point - I have the MT Propeller P-860-4 with a Hartzell HC-C2YR-1BFP-F7497 and it cycles fine at 1700 RPM when I do my run-up.

Ditto for my Hartzell gov and Hartzell composite prop. IO360 M1B.

Nice service by Aerosport to remove that plug!! That is good information for the database.
 
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Lycoming Service Instruction 1462A

Everyone else has already said everything I think I would try first.

I am thinking it may be time to do Lycoming SI1462A.

Following is copy/paste from Lycoming website.

PROPELLER OIL CONTROL LEAK TEST PROCEDURE PUBLICATIONS
Supersedes Service Instruction No. 1462

July 10, 2003

MODELS AFFECTED
All Lycoming Direct Drive aircraft engines equipped with a propeller governor.

TIME OF COMPLIANCE
1. Whenever sluggish propeller action is reported.

2. Whenever the engine does not hold RPM during cruise, climb or descent.

3. Whenever the engine is going into feather during landing roll out with reduced throttle setting.

Front and rear mounted propeller governors are used on Lycoming engines. The purpose of the air pressure check to the propeller governor system is to determine if the governor oil passages have openings (excessive clearance), leaks or restrictions, or blockages (tight clearance).
 
governor gasket

Happend to me when building a rv-7. It end up to be the wrong gasket between the governor and engine.
 
Confirmed the correct rear plug was installed and the front plug was removed. Reinstalled the prop. Pulled the governor. The oil flow path has me a little confused so I'm waiting to hear back from APS about that. Correct gasket was installed in the correct direction. Aerosport confirmed that the engine passed the pressure check in 1462A before it left the factory. I also pressurized the engine with the pre-oiler and a ton of oil came out of the oil port with minimal pressure. I've got a higher pressure gauge on order so I can tap into the adapter and see how much pressure is going forward to the prop. If APS confirms the governor is correctly setup, I'll reinstall it tomorrow and try the cycle at a higher RPM.

Edit: what I have labelled as "restrictor?" is the pressure relief valve as confirmed by APS. It dumps the extra pressure/flow above 300psi back to the inlet of the pump.
 

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This may be a stupid question, but is the drive gear in the governor drive housing- and does it turn with the crankshaft?
 

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I had this happen to me.

Another idea.......

Hey I had a similar problem after remounting an Aerosport IO-540 on my RV-10. I had a deer strike and had aerosport power go through the engine, I also sent the governor and the prop in for overhaul. After I mounted everything my prop wouldn't cycle. I called all the vendors to see what was up. I made a plate covering the governor mount and used a pressure gauge to check the prop oil circuit. It checked out okay. Aerosport was very good to work with trying to figure this out. It ended up being a bad o-ring after the prop overhaul. The prop was hydraulically locked in one position from oil being on both sides. The way I verified was manually trying to twist the prop (two of us). My friends prop would move freely but mine wouldn't. I had to send it back and get a new O-ring. It now works. You should be able to twist the prop with one of you on each blade of the prop. Mine is a two blade blended hartzell.
 
Still waiting to hear back from whirlwind for any prop troubleshooting steps, but I'll grab some helpers and see if we can twist the blades manually.

APS confirmed the setup on the governor was correct and it should be working. There's a 1/8NPT pressure port in my governor adapter. I'm waiting for a 500psi guage to show up tomorrow so I can see how much pressure is being sent to the prop. Also confirmed that the drive gears are all in place and the engine side gear only turns when we turn the prop by hand. Everything looks like it should work just fine.

Gonna pull it onto the ramp tomorrow for for some cycle attempts at 2300-2500 rpm.
 
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...
Gonna pull it onto the ramp tomorrow for for some cycle attempts at 2300-2500 rpm.
I know you know this, and BillL included a reminder, but anyway, make sure you find a good way to tie down that beast before running at much over 1800. And point the aircraft to open space just in case it gets loose.

I did a few high power ground tests and it was scary, and I had it securely tied down to each gear leg, and then through the tailwheel to keep it down.

And make sure that you have a friend with a very low quality phone camera in vertical mode in case it does get away. :D
 
Had a similar issue a few years ago after an overhaul. Crankcase shop installed hollow pins instead of solid pins in the front main bearing. This was only discovered after weeks and weeks of troubleshooting and sending the engine back for tear down.
 
We put a pressure gauge on the exit of the prop governor. It reads zero psi at all rpm and pitch settings. It's not even letting engine oil pressure pass through it. We have confirmed that oil pressure is present at the entry to the governor, so not sure what's going on inside it, but it looks like I get to send it in and have it checked out. I'll know more Monday or Tuesday when I can talk to APS again.
 
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Prop Not Cycling

I had a similar problem several years ago with my Skybolt. Engine was a Lycoming IO-360-A1B6D angle valve. Prop governor was a Woodward. Problem: Prop would not cycle.

Took the prop and governor to a propeller repair shop. Everything checked out OK.

Shop owner asked me "Did you install the prop governor plate?" The what...?

Lycoming parts manual Item LW-12347 Plate, propeller governor pad.

Installing this plate solved my problem immediately. Just a suggestion.
 
I had a similar problem several years ago with my Skybolt. Engine was a Lycoming IO-360-A1B6D angle valve. Prop governor was a Woodward. Problem: Prop would not cycle.

Took the prop and governor to a propeller repair shop. Everything checked out OK.

Shop owner asked me "Did you install the prop governor plate?" The what...?

Lycoming parts manual Item LW-12347 Plate, propeller governor pad.

Installing this plate solved my problem immediately. Just a suggestion.

I was confused by this requirement when I installed my prop governor. See this service bulletin:

https://www.lycoming.com/sites/default/files/Propeller Governor Pad Plate PN LW-12347.pdf

This gasket/plate configuration is for a governor that installs directly to the accessory case, without a governor drive adapter.

What was confusing to me is it calls for this on a dual mag case- but there’s only one mag hole. That one hole is for a dual mag drive assembly. My accessory case has two mag holes and a governor drive adapter.
 
Late to the thread, but had a similar issue new engine, hartzell governor (new from Vans), hartzell composite prop.

Pulled the prop (no plug)

Built a plate, checked oil pressure at the inlet (good), Air would move the blades, I did the entire lycoming test and it passed with flying colors.

Sent the governor to a shop and when they pulled it apart it was assembled incorrectly. They put it back together, tested good. I reinstalled and it worked perfectly, and will cycle fine at 1600 rpm .

Not sure how (maybe someone took apart and returned? maybe from the factory that way- but it was borked).

Sucked to have to pay to get a new governor fixed, but Hartz said they were all tested at the factory, and in the end was cheaper and quicker than most of the other alternatives.

Hope you get it figured out quickly and it is a simple fix
 
Put a pressure gauge on to see what was making it to the prop. Zero. Nothing. Not a single PSI is getting into the prop oil line coming out of the governor. Did a bench check and it seems like the governor is pumping oil when i turn it, so I'm not sure where the blockage is. Gotta dig into it some more tomorrow.

Did the 1462A pressure check and got 35psi on the leak down gauge. It's the upper limit, but is within range. It also confirms that the crank plugs are in fact in the right spots.

Also checked that the coupling was properly installed and it looks like its good. Pic attached.

Now I wait until Tuesday to see if APS wants the governor back to inspect it, or if there's some more troubleshooting to do before we reach that step.

https://youtu.be/J37KDUkyGSg

https://youtu.be/PyJqauPY_Wo
 

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Crank plugs

Are the crank plugs correct?

You may still have the Front plug in, or the rear plug is punched or not there.

My engine was delivered with a front plug installed by lycoming
 
Are the crank plugs correct?

You may still have the Front plug in, or the rear plug is punched or not there.

My engine was delivered with a front plug installed by lycoming


Already verified the plugs are correct. Front plug is not installed, rear plug is solid. Pressurizing the governor discharge line with air gives the proper leak down rate, and if air pressure in the line is increased it will move the blades.

Main problem that I can tell is that the governor isn't outputting any oil. Seems to work fine on the bench, but the discharge line is mainly dry with no pressure being built up.
 
Aerosport is saying it passed the pressure check at that port before it left the factory. We pressurized the oil system to around 30psi and a ton of oil came out of that port. I'm going to make the block off plate and verify the pressure is there, but there seems to be no issue with the supply. Gonna take the governor to a prop shop tomorrow and bench check it. I'm sure it'll check fine.

I found this old thread, https://vansairforce.net/community/showthread.php?t=42005
And it seems like his problem was that he couldn't build pressure unless he sealed up his crank vents. Ive already verified my nose section holds the right amount of pressure so I don't think it's the same issue he had. Did he just start his engine and let 8 quarts a minute flow into a bucket to verify the flow rate though?
 
I was confused by this requirement when I installed my prop governor. See this service bulletin:

https://www.lycoming.com/sites/default/files/Propeller Governor Pad Plate PN LW-12347.pdf

This gasket/plate configuration is for a governor that installs directly to the accessory case, without a governor drive adapter.

What was confusing to me is it calls for this on a dual mag case- but there’s only one mag hole. That one hole is for a dual mag drive assembly. My accessory case has two mag holes and a governor drive adapter.

I'm confused by this plate. I have a governor drive adapter, but the adapter doesn't have this plate between it and the accessory case. The governor drive adapter just has a normal gasket between it and the engine. Anyone with pics of this plate? Or a better explanation on what it does to the flow of oil?
 
Aerosport is saying it passed the pressure check at that port before it left the factory. We pressurized the oil system to around 30psi and a ton of oil came out of that port.

Have you placed a gasket on the engine and visually made sure the port was not covered?

Then, hold the gasket up to the gov and make sure it aligns with the correct port there also?
 
Have you placed a gasket on the engine and visually made sure the port was not covered?

Then, hold the gasket up to the gov and make sure it aligns with the correct port there also?

I have. The correct ports are open. Just did a flow check and got 2 quarts a minute while just turning the motor over with the starter. I assume with the motor running and actually making more than 10psi, the flow rate at the governor inlet will be up a lot closer to the 8qt/min max flow rate the pcu5000 can handle. everything about this system says it should be working fine. I think my last hope is the prop shop finds something wrong with the brand new governor.

I also found a bunch more info on the spacer plate that was mentioned.

https://www.cardinalflyers.com/tech/info/govplate.php

My confusion was mainly from the "all 4 and 6 cylinder dual magneto engines". I assumed that meant every Lycoming, since they all come with dual mags. Turns out they mean a specific accessory drive where it drives both mags from a single hole in the accessory case. It's just a spacer to prevent the shaft bottoming and an oil leak, not sure why it would affect pressure or flow at all. It also makes sense why engines with additional governor mount pad adapters don't require it. So for now I'm going to skip making and installing that plate. Open to hearing other opinions on it, but that doesn't sound like my issue.
 
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I installed the same setup whirlwind 300 with their Jihostroj governor. I had the same problem nothing would happen when you cycled the prop. I also put a pressure gauge on the outlet going to the prop and at 2000+ RPMs it would shoot to 350 then back to zero. I removed the control cable and tied a strap to the governor's arm and used that to engage the governor. I ran it up to 2000 RPMs and the prop cycled. I tried it at different RPMs and it cycles at anything over 1200.

Now I need to figure out how to get the cable to work. It doesn't have enough throw to go stop to stop. And I tried the arm in different positions but would lose max rpm.
 
I installed the same setup whirlwind 300 with their Jihostroj governor. I had the same problem nothing would happen when you cycled the prop. I also put a pressure gauge on the outlet going to the prop and at 2000+ RPMs it would shoot to 350 then back to zero. I removed the control cable and tied a strap to the governor's arm and used that to engage the governor. I ran it up to 2000 RPMs and the prop cycled. I tried it at different RPMs and it cycles at anything over 1200.

Now I need to figure out how to get the cable to work. It doesn't have enough throw to go stop to stop. And I tried the arm in different positions but would lose max rpm.

Yes, this is very important, not just for your prop but for your throttle and mixture. Ensure that you get full throw, stop to stop, on all three. If you can't do it with the cables and levers you have, perhaps get an extra pair of eyes on it.
 
Yes, this is very important, not just for your prop but for your throttle and mixture. Ensure that you get full throw, stop to stop, on all three. If you can't do it with the cables and levers you have, perhaps get an extra pair of eyes on it.

It's interesting because APS has said that hitting the low speed stop is not required on the governor. You reach minimum controllable RPM prior to hitting the low speed stop, and he sounded surprised that I had it setup to go stop to stop.
 
It's interesting because APS has said that hitting the low speed stop is not required on the governor. You reach minimum controllable RPM prior to hitting the low speed stop, and he sounded surprised that I had it setup to go stop to stop.

Lots of variables going on in the prop, governor and oil supply. Real stops can be in the prop, or a limitation of travel or pressure in the governor. Even if the physical travel stops are hit, spring changes can bring operation back in range - again . . . depending on the balances of specific physical limits required.

My Hartzell composite prop (and hartzell governor) hits the stops as the physical limit of the angle is reached for the airspeed&rpm. It just won't slow the rpm any more as the prop pitch is limited. At this point the lever/control position does nothing.

My governor has a dead band in the "lever" at both ends of the range . . depending on airspeed.
 
It's interesting because APS has said that hitting the low speed stop is not required on the governor. You reach minimum controllable RPM prior to hitting the low speed stop, and he sounded surprised that I had it setup to go stop to stop.

I would of course trust APS over a random guy on the internet - they've forgotten more about this stuff than I'll ever know.
 
APS found that the governor was missing a "speeder spring", so it was sitting in full course pitch all the time, regardless of position of the control arm. It's on its way back to me now, I'll update over the weekend once I have a chance to reinstall and test it out.
 
APS found that the governor was missing a "speeder spring", so it was sitting in full course pitch all the time, regardless of position of the control arm. It's on its way back to me now, I'll update over the weekend once I have a chance to reinstall and test it out.

Thanks for updating us on the issue, and thumbs up for your troubleshooting this PITA problem.
 
To fully close this out, we did an engine run today after getting the governor back from APS. Prop cycles as it should. I ran it up to 1800 and it only took about 2 seconds with the lever pulled before the rpm dropped on the first attempt. Looks like we're good to go.
 
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