Stuka Stunt Main Forum · 11 of 11 known posts recovered
When the character of a man is not clear to you, look at his friends.
Japanese Proverb
Stephen, I've always changed the remote needles to the the OS Max venturi and needle valve from the FP. I've thought that the remote needle just wasn't as good as this set up. That is until last sunday! !
While flying with Roger (66ragman) Strickler, Gary Tultz and Ralph, Roger broke out a hybrid magician/trashcan plane (Roger can tell that story....make it short Roger 
) with a 40la that still has the remote needle. I flew it once and without a doubt that is one of the sweetest running 40LA's that I've ever seen. It will run a breaking wet two stroke and when you lift the nose it breaks into a strong two stroke. Fly an inside loop and it breaks going up and settles back on the down side. Almost like a light switch..... very sweet. Now I'm not sure a change is necessary.
I believe the engine is box stock. The only knock might be the durability of the plastic backplate. Plastic deformation over time under the load of the screws can cause leaks. Solution would be the metal backplate from from tower and the metal bracket remote needle assy that came on the last series of FPs.
Roger could add to this ,,,, but keep it short Rog.
"Straighten up and fly right"
Rog
A lot depends on the type of plane. I prefer the front needle to the remote on a stunt plane. However, if you are planning a profile, the remote can be made to work. Just beware of the stock venturi stories. OS has changed venturis on the LA series so often that there is no such thing as "stock". If anyone says they did "this" with their stock engine and it ran just fine, ask them what venturi they have and compare it to yours.
If you do put a front needle on the engine, (can't hurt, can help, becomes necessary almost on a cowled engine) the front mount FP needle bolts right in. You need to drill out the cross-hole to .157 diameter if you use an ST needle and then it will choke down your venturi. This may be good or bad depending on which venturi was supplied with your engine.
As mentioned elsewhere, changing to the metal back plate is always a good (and inexpensive) idea. If you keep the remote and have the metal bracket you are OK. If not you will need to switch to a metal bracket as well. If have these, but then, why not just go to the front needle then? The rear bracket can sometimes save the needle if you like to play lawn dart. I guess the choice remains up to you.
Leonard Neumann
John Thompson
The OS 25-40 FP needle valve is a drop in replacement for 40LAS and also the 46LAS
The OS 40 FP backplate is also a aluminium replacement for the OS40LAS AND OS46LAS plastic backplate.
You can also purchase some 3mm socket head screws if you like and replace the phillips head screws in the back plate and cylinder head.
To fit the needle valve assemblies, simply remove the spraybar from the venturi, and replace with the needle valve assembly
I have 3 OS46LAS motors all modded like this and they run fine
I found the backplate phillips head screws working lose all the time
so opted for the socket head screws.
Glenn Block.
As len mentioned, OS has shipped a number of different ID venturis that fit these engines. They also have shipped them with different thickness head shims- we've found .005, .008, and .015in. So you really need to measure what you've got.
Phil C
John Thompson