Throtlle goes back to flight idle on its own
- Thread starter N197BC
- Start date
Steve Pierce
BENEFACTOR
Graham, TX
Yes, there is a castlared nut at the base of the throttle handle. Remove the panel and cotter pin and tightened.
btracy
FRIEND
Ohio
Plus check check for the correct parts. There is also a friction washer between the throttle lever and the bracket. When I first took mine apart it just had a stack of washers in it. The one the I got from Univair looked like a piece of gasket paper. Alaska Bush Wheels had some made up that were made of delrin or some such thing.
WindOnHisNose
BENEFACTOR
Lino Lakes MN (MY18)
Getting the friction lock just right is a bit of a trick, keeping in mind that you have both throttle handles connected, each contributing to the movement. I have had mine too loose, and have had them too tight. Even now I find that mine creeps back a little bit in cruise, with the vibrations, etc, so that genius, Bill Rusk, pointed out that an appropriately folded piece of paper, or formerly a matchbook, could be gently wedged between the housing and the throttle in order to add a bit of a "friction lock".
Randy
Randy
cubdriver2
FRIEND
upstate NY
Its fun to sit in the back seat of the J3 with someone who is used to flying something like a Cessna in the front seat. As the rpm drops they add carb heat and as it continues to drop they start looking for places to land till they can't stand it any more and yell " do something " . And I push the throttle forward. Fun to mess with spam can drivers.
Glenn
Glenn
mike mcs repair
Registered User
chugiak AK
Also... Check how the alignment is at carb conection and throttle arm indexing.... It will try to creep to its relaxed position
Dave Calkins
Registered User
Anchorage, Alaska
For the EXP guys......
install a missile nut in place of the castle nut and cotter key. Drill a hole in the cover panel that will fit a socket that fits the castle nut....voila, an easy way to adjust the friction. PS, a knurled knob could be fabricated that allows in-flight adjustment instead of the castle nut or missile nut, but I have not found it necessary to fiddle with after doing the missile nut thing and periodically adjusting it.
install a missile nut in place of the castle nut and cotter key. Drill a hole in the cover panel that will fit a socket that fits the castle nut....voila, an easy way to adjust the friction. PS, a knurled knob could be fabricated that allows in-flight adjustment instead of the castle nut or missile nut, but I have not found it necessary to fiddle with after doing the missile nut thing and periodically adjusting it.
skywagon8a
MEMBER
SE Mass MA6
Dave Calkins
Registered User
Anchorage, Alaska
Excellent!
That is funny. I'll have to try that one.
Steve Pierce
BENEFACTOR
Graham, TX
What is a missile nut?
Dave Calkins
Registered User
Anchorage, Alaska
Steve, MS 21042......from that base number you can select the finish plating and dash number for size.
Are you serious?
http://www.aircraftspruce.eu/Hardware/Nuts/Stop-Nuts/AN363---MS21042-ALL-METAL-STOP-NUTS.html
Are you serious?
http://www.aircraftspruce.eu/Hardware/Nuts/Stop-Nuts/AN363---MS21042-ALL-METAL-STOP-NUTS.html
Steve Pierce
BENEFACTOR
Graham, TX
Always called the Jesus nuts.
Dave Calkins
Registered User
Anchorage, Alaska
Always called them missile nuts.
Steve Pierce
BENEFACTOR
Graham, TX
It is actually a phenolic material. Same material as the phenolic washers in the 3400 tail wheel.
jgerard
Registered User
Seattle, WA
It's important to have the special Piper "D" washer behind the castle nut that rests against the tab which keeps it from rotating or you won't be able to set the proper friction. I have seen airplanes with regular AN washers which is incorrect. Look in the parts manual to see how it all goes together.
Sorry I don't have a picture for that area right now.
Jason
Sorry I don't have a picture for that area right now.
Jason
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Steve Pierce
BENEFACTOR
Graham, TX
skywagon8a
MEMBER
SE Mass MA6
John, The Delrin is just for the knob. The friction is generated with the piece of shoe leather. I wanted the friction to be adjustable in flight just "because". And, as you know, this is experimental. Though I would not hesitate to use a piece of old shoe leather on a certified plane for this purpose.
Darrel Starr
Registered User
Plymouth, MN
Steve, live & learn. I had never heard of the gasket between Scott 3200 wheel halves but there it is on the Bushwheels exploded view. I have had 4 to 6 of these apart and never noticed a gasket. Of course the gasket might have been thoroughly stuck to a wheel half but I don't think so - probably just missing. Function? Probably to prevent Fretting of the wheel halfs as they work against each other. Guess I ought to order a couple of them. Thanks.
Dave Calkins
Registered User
Anchorage, Alaska
Years ago the Scott representative told everyone to remove that "gasket" and leave it out. It was causing fretting and broken bolts. FYI
skywagon8a
MEMBER
SE Mass MA6
Delrin is more apt to be slippery. I would use a piece of old shoe leather for this purpose, as the tension can be adjusted giving the desired amount of friction.
SteveE
SPONSOR
Jenks, OK
OK. Thanks. I'll try to get a scrap of leather. Perhaps just like the leather used to protect the fabric where rudder and aileron cables exit the plane.
What should the maximum thickness of this old shoe leather be? I've seen the gasget paper washer before and it is tissue paper thin.
