Head Coming Loose?

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Phill2

Phill2

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Hi Guys


My head and exhaust keep coming loose even though I've used red loctite and anti shake washers.


Does anyone have any ideas on how to keep em tight?


Thanks


Phill
 
Loctite should work.

Are you letting it dry 24hrs before use?

The exhaust bolt holes on the heads can become worn easy. I use studs. Red loctite them in and let fully cure. I never take them out again.
 
What torque are you using on the head and exhaust. Should be 83 in/lbs. Should get a new cylinder gasket, too. Sometimes you can get away with reusing one, generally nope, the cylinder won't stay torqued down. I don't use Loctite on steel into aluminum, it throws off the torque reading, and with steel into aluminum it isn't needed, and can cause stripping out of the screw heads or threads in the aluminum when you attempt to remove the screws.
 
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Here's the torque values Zenoah publishes.

MAINTENANCE 6) TIGHTENING TORQUE Items Screw Size Standard (N·m) Limit (N·m) Remarks

Carburetor M5 (P=0.8) 3.4 2.9~3.9

Insulator M5 (P=0.8) 4.4 3.9~4.9 with Locktight glue

Clutch M6 (P=1.0) 6.4 4.9~7.8

Rotor M8 (P=1.0) 12.7 9.8~14.7

Cylinder M5 (P=0.8) 6.8 4.7~8.8

Crankcase M5 (P=0.8) 6.4 4.9~7.8

Spark Plug M10 (P=1.0) 10.8 8.8~12.8

Muffler M5 (P=0.8) 8.8 6.9~9.8

Fan Cover M5 (P=0.8) 3.4 2.9~3.9

Ignition Coil M4 (P=0.7) 3.2 2.5~3.9

Starter Case M4 (P=0.7) 1.3 1.0~1.5

Tapping Screw TP 4.3 2.4 1.9~2.9

Noticed your Aussie address, so I didn't convert to in/lbs. Note the only place Loctite is mentioned is the plastic carb insulator, which expands and contracts and is flexible. Keep the threads clean and dry before you torque, recheck after a tank of running and you should be good to go. Did some work on air cooled recip aircraft engines eons ago, Loctite was a major NO NO.

I missed a chance to visit your wonderful country when I was flying out of Diego Garcia, had a family emergency. So while my crew went to Perth, I headed to San Jose, CA via Kenya, Greece, Spain and Norfolk, VA via a USAF C-141. Then to Japan with a stop in Anchorage, AK to catch up with my crew. And darn glad to get back in a P-3!
 
Last edited by a moderator:
Chief409 said:
Here's the torque values Zenoah publishes.MAINTENANCE 6) TIGHTENING TORQUE Items Screw Size Standard (N·m) Limit (N·m) Remarks

Carburetor M5 (P=0.8) 3.4 2.9~3.9

Insulator M5 (P=0.8) 4.4 3.9~4.9 with Locktight glue

Clutch M6 (P=1.0) 6.4 4.9~7.8

Rotor M8 (P=1.0) 12.7 9.8~14.7

Cylinder M5 (P=0.8) 6.8 4.7~8.8

Crankcase M5 (P=0.8) 6.4 4.9~7.8

Spark Plug M10 (P=1.0) 10.8 8.8~12.8

Muffler M5 (P=0.8) 8.8 6.9~9.8

Fan Cover M5 (P=0.8) 3.4 2.9~3.9

Ignition Coil M4 (P=0.7) 3.2 2.5~3.9

Starter Case M4 (P=0.7) 1.3 1.0~1.5

Tapping Screw TP 4.3 2.4 1.9~2.9

Noticed your Aussie address, so I didn't convert to in/lbs. Note the only place Loctite is mentioned is the plastic carb insulator, which expands and contracts and is flexible. Keep the threads clean and dry before you torque, recheck after a tank of running and you should be good to go. Did some work on air cooled recip aircraft engines eons ago, Loctite was a major NO NO.

I missed a chance to visit your wonderful country when I was flying out of Diego Garcia, had a family emergency. So while my crew went to Perth, I headed to San Jose, CA via Kenya, Greece, Spain and Norfolk, VA via a USAF C-141. Then to Japan with a stop in Anchorage, AK to catch up with my crew. And darn glad to get back in a P-3!
Click to expand...
Thanks for all your work Chief

Maybe you'll make it here one day - it's a great place
 
I haven't done this myself yet, but my buddy put a new top end on his 5b.

Kept blowing gaskets and loosened up bolts.

He ended up using a copper gasket and copper gasket sealer.
 
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