I just received my 4* and I have a Saito 72. The throttle arm is so close to the fire wall and side of the frame I’m not sure what to do. I don’t want to cut out some of the side.

You can try using a long throttle push rod and bend it back in a "U" shape & connect to the throttle arm if there is clearance. A better option would be a Du-bro 4-stroke linkage: http://www2.towerhobbies.com/cgi-bin...?&I=LXD939&P=7 It works pretty good.

Any pictures of this installed before I order it?

The U shape push rod would work well.

I just installed a Saito .62 in my ARF Four Star and used the Dubro 4 stroke linkage (part # 655), 2 x Dubro ball links (part # 190) and a 1" length of 2-56 threaded rod.

See the picture for a mockup that i assembled off the model for clarity.

You might also need to drill 2 holes in the cowl cheeks for the needles, depending on the size of the motor.

CustomPC, pardon my ignorance but my throttle valve is on the far right side of the engine (Facing it). Did you modify your 62 or is it set up different?

You can rotate the throttle barrel to either side. It makes no difference.

Undo the 2 screws holding the carb. Pivot the carb and intake pipe about 45 deg clockwise. Rotate the carb 180 deg and then pivot the carb back.

Do I need any gasket sealer or anything when I do this? Thanks for the info. I have a new 72 and I haven’t even broken it in yet so I’m just learning. Can’t wait to fly the 4* with that 72

No gasket sealer needed as the carb and inlet pipe are sealed with 'O' rings.

I think you'll find that the .72 is too much for the Four Star 40. I flew mine the .62 for the first time today and needed 2oz of lead at the tail to balance correctly.

The .62 had no problems hauling the 4* around the sky, even when running at break-in slobbering rich.

I've head most people use a 51-56 size 4 stroke on the 4*.

I was going to ask how the balance was with a 62 The 72 is all I have to go on it. I’ll try to get the batteries toward the rear.

yeah, i'm not too happy with the balance yet.

I have 2 ounces of lead in the tail and the 1700mAh battery is jammed up against the servos as far back as it will go.

I needed all of my up trim to get the model flying straight and level which indicates it's still nose heavy.

When i get home from work i'm going to see if theres anywhere further rearward i can mount the battery. I also have a smaller/lighter 1100mAh pack to try and see if that makes a difference.

I'm also thinking of getting a lighter 2-stroke up front and shifting the .62 to another model.