Hello,

I have a Hobbystar 60 ARF that I am putting together. I got a Magnum .91 4 Stroke for it. How do I hook the throttle linkage up? The Need Valve is on the left side of the engine (opposite of the Exhaust). With the carb this way the throttle link is pretty much dead center of the engine. If I turn it around it will get the throttle to one side, but the needle valve will be on the same side of the plane as the exhaust, which I don't want to do. Is it safe to do a little Z bend of the throttle linkage to allow it to reach the engine?

Also, the engines carb is going to be about 3/4 inch higher then the fuel tank outlet. I hope this wont be an issue since the ARF doesn't give you much room to move around.

Thanks,

Joel

Joel, I have the Magnum 91RFS in my 4*60. From the photos I've seen of the Hobbystar 60, the engine compartment is near identical. My engine has the high speed needle opsite to the exhaust. I use a ball link and a cable for linkage. Using the flexable cable, you can route the linkage around the fuel tank. I battled hard linkage on a couple models before settling on the cable setup. Just keep the amount of cable out of the housing to a minimum and it works really well.

Don

Make whatever bends you need to get it to work. Worst thing that can happen is you ruin the wire and have to buy a new one (happens to me).

The slightly low tank height should not be an issue. The Magnum has good fuel draw, and this is not a high performance aircraft. If it does lean out in flight as the fuel level drops, just start your flights with a richer mixture. You can do this by tuning it on the ground with about 1/4 tank. Fill up and fly.

Here is how I do it.

You can even bend the throttle rod in a horse shoe shape at the throttle arm to approach the arm from the front.

I've also made them with all sorts of "dog leg" shapes. They seem to work very well

I've also done them with a bell crank

I used the Dubro 4 Stroke Linkage and some ball joints (See Pic)

I understand your point about the placement. If you have the throttle linkage on the outside of the engine, the needle valve is near the exhaust which can make it a little difficult sometimes to adjust it without burning your fingers. If you have the Throttle arm in the centre of the engine, there is often not enough room between the firwall and the arm to fit a clevis. Experimentation is the key here.

I'm not familiar with the Hobbistar but I have used various configurations of z bends on different planes and they work well. Otherwise - locate the arm on the outside of the engine and a setup like Hobbsy shows works well. You may want to make an extension for the needle valve from a piece of wire to be able to adjust it easily.

I use the same system as Custom PC no slop I rotated the Carb 180 degrees, that puts the the needle on the other side (of course the linkage flips to the other side too)
martin
I used the ball joint thing and made the lever from an extra servo arm with one end cut off had what I needed in the extra parts stuff