I've been experimenting with the variable adjustable choke idea that Bob Reeves talks about - here is my variation of it.

I made a 90 degree aluminum bracket, that bolts to the two bottom backplate bolts on the Saito.

On it is epoxied a balsa block to create a support and tight friction thread for a nylon bolt threaded through it.

The center of this nylon bolt's head  is fastened a servo screw with a hex head. It is force-threaded into the nylon bolt so it cannot turn on its own. The end of the threaded side of this nylon bolt is tapered to a cone shape.

I threaded the bolt through the balsa block until it fit slightly snug inside the venturi, forcing the balsa block up against the bracket I made.   Once that was done, I epoxied the block to the bracket, and once cured and stable, the whole subassembly was fastened in place.

A small hole was made in the top nose of the airplane to access the bolt with a ball driver that could turn the servo screw, and hence, turn the nylon bolt.  The fusalage hole was lined with 1/8th brass tubing to allow precise allignment of the tool - to -screw fit. 

Everything was put back together and I tried  it out last night with Dave Cook.  Works very well, and we are
still experimenting with it, but I need some imput from Bob Reeves. This is a cool way to have an infinitely adjustable carb. And if you don't need it, you don't have to use it..

Pictures are included with this post - I hope they come out..

Bob;

I thought about that possibility.  I think I will mount 2 small bolts to hold the balsa block to the aluminum mount.  sucking up a nylon bolt into the manifold during a critical maneuver would be rather catastrophic indeed.  Not a good thing.


During practice last night, this airplane did a reverse wingover with a 5.9 sec lap speed, out there in the hemisphere on 64 ft. eye to eye lines.  It just clawed its way over the top and down the other side.....I've never experienced that before...most impressive.. We are talking an airplane about 75 -80 oz. in weight.  I'm currently using a stock, un-modified Zinger square tipped wood prop, 13 X 6...Dave Cook  is coaching, advised me to just fly this airplane for awhile before doing anything different.  We have adjusted airpeed to about 5.2 - 5.3 sec lap speeds.  I'm thrilled to fly this airpane with this set-up !

If any need further info, just ask , please.

Will Moore