b.bixel

My Feedback: (123)

The plans for CG Ultimate show 0 deg down and 2 deg right thrust. The manual has a page showing the YS 120 with a 3-4 deg right thrust. I using the OS 120 Surpass III, so I set things up 3 degrees to the right. I however don't care for how the cowl fits on the left side of fuse when I need to push it over to match the cowl to the spinner. There is a big gap on left side because the cowl slides down over the fuse far behind the firewall, and since the firewall is wide things the cowl pivots on the firewall like a teeter-totter, leaving a big gap on left side.[:@]

Anybody flying this plane with 0 deg right thrust? How does it fly?

Regards,
Bart

ghendrix01

My Feedback: (1)

Bart,

If you look at the illustration on page 59 of the Ultimate manual and compare it to the plans, you will see that the engine mount needs to be moved to the right to get the cowl to line up with the engine shaft. Also, if you look carefully at the illustration, you will see that the spinner backplate is not parallel to the front of the cowl. Goldberg does not tell you this stuff in the manual. I guess they must think that you will see it. I believe the original distance was about 3/16 inch, so move the mount an additional 3/16 inch to the right or if you can still see the scribe marks, just measure the distance and double it.

I hope you understand this,

George

b.bixel

My Feedback: (123)

George,
Thanks! You just confirmed what I figured I needed to do. Shift the engine to the left (port side) so the 3 or 4 degree angle intersects the aircraft centerline at the prop hub face. My kit was orginally built with 0-0 degree thrust line. I'm attaching some pics for those who might need it in the future.

1st pic is from the manual,
2nd pic is my firewall,
3rd pic shows where my engine was mounted (left mark),
4th pic shows where I must move it to get my 3 deg (right mark).

I'm lucky I have plenty of room to re-drill my motor mount as I'm not going to be able to get behind the firewall to install new blind nuts.

Regards,
Bart

GrnBrt

My Feedback: (5)

I here your anguish Bart as I had the same problem. I finally got the engine lined up and then cut a plywood circle and glued it to the front of the cowl and sanded the front to fit the offset, what a pain that was but it worked.