I just purchased the Magnum 52 for my UltraStick 40. It has the parts to either set up with a standard needle valve direct to the carb or a remote needle valve set-up with the valve behind the engine. This is my first build (I'm a real noob), so I don't know much about this. The remote valve seems to have the obvious advantage of being about to tune without chopping your fingers off, but are there negatives? Can this cause performance issues with inconsistent fuel feed because of the section of tubing between the needle valve and the carb?

Thanks in advance, guys. You're always super-helpful.

It is probably safer that you set it up with the rear needle valve for now. You can always change it back later if you desire.

Frankly I've never had any trouble using a rear needle valve. But have a few skinned knuckles from adjusting front needle valves.

What he said.

I've heard people say they had performance issues with remote needle valves but I honestly think they had other problems and just blamed it on the needle valve location. I've never had an issue with one.

Another determining factor may be the installation. One needle location might work better than the other on certain airplanes. For your Ultra Stick though, either way will work.

Motioned.....second....all in favor? Aye.

I have to agree, especially in the beginner's forum. My first engine was a rear-needle and I am very thankful for that. I was going to say it give you the opportunity to get more comfortable around the running engine, but you should never get too comfortable. Maybe it's better to say it gives you some space to learn safe habits before you have to put your hands 1.5 inches from something that can take your fingers off.

Rear needles will take a second longer to affect the engine, so if you make an adjustment and do the pinch test or tach your engine, just wait an extra second.

Have had no problems with the rear needle. My engines now come with a forward needle that is angled back; sort of the best of both worlds.

the remote works great. occasionaly check the short fuel line for holes. if none are found then there is no problem

I have both remote (rear mounted) HS needle valve and the front mounted (directly to the carb) types. The latest OS engines, the AX series, have a front mounted needle valve assembly however, it is pointed to the rear with a wire that you can attach to the inside of the needle valve, that puts the adjusting knob well away from the prop, thus making this as safe as a rear mounted (remote) needle valve.

I've never experienced any problems with either setup. And I never noticed any sort of delay in making the slight adjustments necessary after engine break in process.

The only problems that can be encountered is the potential for pin-holes in the tubing which can be alleviated by carefully selecting the proper tubing and not stretching it to it's total length before using it. Those little holes can cause lots of problems, so using new, and good condition tubing all the way from the clunk to the carb is of prime concern. If you insure your tubing is in good shape, is mounted and attached with no leak possibility, it will be just fine no matter if you have a front (direct) or rear (remote) mounted HS needle valve assembly.

CGr.

The remote needle valve is an inefficient option comparing with the direct needle valve. The answer:
The entering fuel is intended to enter into a new chamber (which –just as an example- may have leaks) before the fuel gets to the spray bar.
In newer engines this fact is hardly noticeable but there are more chances to fail in comparison as the direct needle carburetor works.
The carburetion range is also erratic (again sometimes hard to notice) while the direct needle will have a wider and safer range of carburetion.
Vibration is also a constant issue that have been reported in other threads here at RCU, been the solution to detach the remote needle valve from the engine and attach it in the fuse (you can see air bubbles in the fuel line between the carburetor and the remote needle valve.
When beginning in the hobby you may choose any of those options but be aware that some issues that affect the carburetion are more constant on those remote needle engine models.
OS engines models have had to deal with some issues and they have gone back to the direct needle valve (angled for the modeler convenience) Thunder tiger engines work fine with this set up now from some years ago.

I hope this comments could be of help.

Alfred.