How do I access the needle valves in a cowled engine?
03-15-2003, 05:37 AM
#1
Member
Thread Starter
Join Date: Dec 2002
Location: Hazel Green, AZ,
Posts: 45
Likes: 0
Received 0 Likes
on
0 Posts
How do I access the needle valves in a cowled engine?
I have a Extra 330L plane with a closed cowl, how do I access the needle valves. Anybody have any ideas on this. 
03-15-2003, 06:01 AM
#2
Senior Member
My Feedback: (4)
Join Date: Feb 2002
Location: CA
Posts: 1,166
Likes: 0
Received 0 Likes
on
0 Posts
drill...
Drill small holes as access points. If the needles allow slotted screwdrivers (as for larger gas motors, for example) then make the holes big enough for the screwdriver to pass.
If you have a situation where you have a knob for the high and a screwdriver slot for the low end, as in the OS .61FX, then use piano wire leading through the hole to the outside for the high needle. The low needle won't need much adjusting, but can be accommodated as described earlier.
If you have a situation where you have a knob for the high and a screwdriver slot for the low end, as in the OS .61FX, then use piano wire leading through the hole to the outside for the high needle. The low needle won't need much adjusting, but can be accommodated as described earlier.
03-15-2003, 06:31 AM
#3
Member
Join Date: Mar 2003
Location: Carlsbad,
CA
Posts: 71
Likes: 0
Received 0 Likes
on
0 Posts
How do I access the needle valves in a cowled engine?
On my H9 Sukhoi with ZDZ I fashioned a small hardwood block holding a pair of brass tubes that just fit over the OD of the adjustment screws (L and H). The tubes were cut to within a quarter inch of the cowl. It is now possible to adjust with a long straight bladed screwdriver either screw (and know which it is) while the engine is running. Initally tried polyvinyl tubing but was unsucessful with it. Have not had any perceived negative effects from this tubing touching the engine screws. No perceptible fretting or wear of the tubing or screw heads after 20 flights.
03-15-2003, 10:25 AM
#4
Member
Thread Starter
Join Date: Dec 2002
Location: Hazel Green, AZ,
Posts: 45
Likes: 0
Received 0 Likes
on
0 Posts
How do I access the needle valves in a cowled engine?
Thanks Mike. I did like you stated but used a small block of PVC and inserted large fuel line out to the inner edge of the cowl it works out great.
Bill
Bill
03-15-2003, 02:35 PM
#6
How do I access the needle valves in a cowled engine?
Solder a hex head cut off a bolt on the adjusting screw....then drill a hole just big enough for a balldriver to go through cowl. The ball driver will never slip off the screw-head like a plain slot screwdriver will. If you try it you will never go back to anything else. Captinjohn
03-15-2003, 02:45 PM
#7
Member
Join Date: Mar 2003
Location: Carlsbad,
CA
Posts: 71
Likes: 0
Received 0 Likes
on
0 Posts
How do I access the needle valves in a cowled engine?
Captinjohn -
I wanted to do the socket head over the slots but was worried that regular solder wouldn't hold in the vibration and silver solver would take too much heat from a torch and damage the carb.
Did you solder with the screws in or out of the carburetor ?
lead/tin solder or silver solder ?
thanks
I wanted to do the socket head over the slots but was worried that regular solder wouldn't hold in the vibration and silver solver would take too much heat from a torch and damage the carb.
Did you solder with the screws in or out of the carburetor ?
lead/tin solder or silver solder ?
thanks
03-15-2003, 03:45 PM
#8
How do I access the needle valves in a cowled engine?
Take the screw out of carb.....sand, file or grind a clean surface....tin it with reg solder or use silver solder. You may be able to use ca or epoxy. The strength is not to important. You NEVER want to seat a needle tight....the fastest way to ruin it. Capt,n
