Hello,

I received a Sig 4*60 ARF (my second plane) from my wife for X-mas. I have purchased a Saito 100 4 stroke that I am having difficultly mounting. The Saito 100 will fit in the stock adjustable engine mount that came with the kit, but the throttle arm is above the fuselage. I tried changing the position of throttle arm so that it points down, but then there is interference with the stock engine mount.

It appears that I have two choices:

(1) use the stock engine mount, but move it down so that the throttle cable will pass through the firewall when the throttle arm in the up position, or

(2) use a different engine mount.

In either case I will have to remove the existing blind nuts and fill the holes. Any suggestions for doing this? Any other thoughts or alternatives?

Also, what is the recommended height of the engine (carb?) with respect to the fuel tank?

Many thanks,

Travis

Dubro makes a 4 stroke throttle linkage just for this problem. It consists of a bellcrank and linkage the will reverse the throw on the throttle. You can also use a 2/56 wire and make a big loop, going forward of the carb and then looping back. The Dubro is a much cleaner solution.

-Rick :thumbup:

You can also duplicate the Dubro setup yourself with a servo arm screwed to the engine mount in front of the engine and a rod going from there back to the throttle arm and the other from the servo to the bottom of this servo arm. That's what I did with my 4*60 kit and YS 91.

Thanks for your helpful suggestions. After fiddling around with the engine mount and using the 4 stroke extension, it looks like it will work as long as I use the first hole on the carb control arm closest to the carb. Hopefully I can make the necessary throw adjustments on the servo end.

Thanks for your help.

Travis

I used a flexable throttle wire that came as a kit with the guide tube. This worked very well and was much easier to work with than a solid rod sonce I had to go up so high. These throttle cables should be available at your LHS. Here is my setup using an O.S. 91 SII w/pump

Eric,

Thank you very much for that shot. I have a throttle cable and tube that came with the kit, so I think I will use that. And the quick link on the throttle arm is very clever. That takes up a lot less space than attaching a clevis to the end of the cable.

Thanks,

Travis

Encountered much the same problem with my kit Four * and my OS 91. Used the Dubro set up and it worked out fine.

Travis,
I'm Glad I could help. When I put my first 4 stroke on a plane I couldn't figure the darn throttle linkage out. I was used to having plenty of room with the front mount carb on 2-strokes. That's when a flying buddy of mine suggested the cable and ez-connector system and that's all i use for four strokes now. you should have seen the wierd bends and bell cranks and other junk that sounded good in my head but were a disaster in practice.

Travis,
Here is how I set my Saito 100 up. I switched the pushrod to the opposite side and set the arm to point up instead of down and used a braided wire as a pushrod tinned on both ends for rigidity.
Hope this helps.
Bill

I used a Dave Brown 4-stroke mount & it worked great. No more clerance problem & I like a one piece mount. I think I only paid $4.95 at the LHS.

That's a great picture. I think I will use the same setup. Bill, what type and brand of connector is that holding the wire to the carb control arm? It looks like it has a metal backing to hold it on. Did you do anything special to make sure it doesn't come off the control arm in flight?

Thanks,

Travis

Hi Travis,
Actually, it was just a keeper I had laying around but there are different ones available from several manufacturers at any hobby shop. Some have metal ends and others use a hard rubber type grommet. DuBro makes some different types. You could probably find several by searching on Tower Hobbies site. By the way, I had to add 4 ounces of lead the the nose of my 4*60 to balance it properly. The Saito is a sweet running engine, I've started adding more nitro and it seems to like it just fine.
Good Luck,
Bill