I put this same question on the Questions and Answers forum.I plan on putting a Saito 56 on my 4 Star 40. As with all Saito the carb and throttle arm are in the back of the engine. What I need to know is how to hook up the throttle cable. It doesnt look like there will be enough movement for the throttle cable to move in the full range it needs to. I only have about 3/4 of a inch ,maybe less for the throttle arm to move.No matter if I adjust the horn up or down. I'm sure the clevis will hit the firewall and not give me the range I need between high and low. So how do you set up a 4 stroke throttle linkage? Do you have to make up your own linkage? Hope you guys can give me some pointers or pics . Thanks, JT

the saito carbs are reversable so you can have the throttle arm on either side. I put mine on the left side.

This is my 4 star 60 with a saito .91

pic

you can use some solder on the cable end to keep it from fraying and to give it some rigidity

Another option. Take the cable/rod to the front of the engine and secure to a servo arm bolted to the engine mount. Run a second rod with connectors on each end, from the servo arm up to the throttle arm.

lhs has a 4s throttle kit for sale,or use solid wire on the throttle control,go past the throttle arm then bend a big C in the wire connecting the end of the C to the arm,have used both methods so know they work.

I like to use the Du-Bro 4 stroke throttle linkage. It fixes your problem of the carb arm being too close to the fire wall. Here is a diagram of how it works.

Thanks for the ideas ! Downwind, I was thinking of going that route , but I thought about the cable binding during movement. But the solder on the cable seems like it would work out great As long as you dont put too much solder on where the cable wouldnt slide in the plastic tube. It seems like a tight fit as it is. I saw the Dubro linkage system, But I didnt think I would have much room between the cheeks and the motor mount for that set up. Sure is a nice set up though. Thanks all! JT

I'm near done building my 4*40 and santa brought me a nice OS46FX to put on it. My problem is that I'm gonna have to grind some of the engine mount diagonal webbing so that the throttle cable has a straight shot. Woulda liked to put a .52 4-stroke on it but santa has a budget too

I like to keep things simple. Have your carb arm on either side. I like muffler side, puts needle valve on left away from exhaust. Put a Great Planes or SIg screw-lock push rod connector on throttle arm, use metal retainer.Put in outer hole on arm , you can also put one on servo arm. I really like Hitec adjustable arm, you can get good travel from it . For the push rod I found 3/64 piano wire is strong enough & bends enough for me. I use a z-bend on servo arm (cheaper). You may need to make a little longer Allen head screw for connector. This set-up works on both two & four strokes. It`s like sex,try it you might like it ! big max1935

I just flew my kit-built 4*40 for the first time today. A whole lot faster than my LT-40 trainer! I used the OS 46FX from the trainer instead of using a new motor, thinking that I knew it was reliable and would keep "new motor" problems from causing a crash. To make a long story short I ran it out of fuel on a takeoff about 50' off the ground, and got to test my dead-stick ability on the new plane on the first day. Couldn't make the runway but got it turned around and level, and floated it into the grass in the field without any damage!
But back to the subject at hand... I carved away a little bit of the motor mount diagonal webbing as suggested above and also loaded the cable end with solder to stiffen it up. Seems to work just fine- and I was able to use the hardware provided with the kit without another trip to the hobby store!

Hey ,what ever works for you & your happy ,what can be better ! Enjoy your 4*40 A good bird ! big max 1935

Redline has the rite idea with the Dubro 4-stroke linkage kit. That is what I used but I added and over-travel spring to keep from straining parts at WOT....Dave

And 4*60 had the right idea saying you could make one yourself out of rod, servo arm and connections.

The bellcrank arrangement is nice, but adds weight and complexity, aside from needing plenty of room between the mount arm and the cowl side.

A better, easier way is a simple wire with a 180 degree loop. This gives you more flexibility on exit points, and provides a sort of built-in servo saver.

Sorry for the lack of detail in the pic, but I'm in the sanding phase, and I wasn't about to mount the engine just for one lousy photo...<G>