I would like to put a YS 120 on my CG Ultimate. I want to use a Dubro Vibration mount. My problem is when using this mount the engine sticks out a good inch more forward then the plans show. My concern is when I go to balance the plane, I don’t want to add two pounds of lead in the tail. By the time I add up the weight of the engine, mount, muffler, spinner and prop, I’m going to have close to three pounds hanging on the nose and to push it out another inch! I’m trying to avoid any major mods like moving the firewall back. I would like some suggestions from others who’ve put YS’s on their CG Ultimates or any other large engine. What kinds of mods did you use if any? Will the mount that came with the kit hold a YS 120? It looks a little skimpy for a 120.

Thanks,
maekju

I used a GP 1.20-1.60 mount on mine to mount a os 120ax. I cut it down to fit inside my cowl. I only used it because I had it laying around... If your firewall is just the stock ply wood I would laminate an additional 1/8" 10 ply aircraft grade to it prior to mounting. If your's becomes to nose heavy mount your elevator servos in the tail. It is an easy mod and it makes the elevators much more positive.

I had to mount my engine quite a ways forward to get it to balance.

There is a lot of info in my build thread > [link=http://www.rcuniverse.com/forum/m_9018718/mpage_1/key_/tm.htm]Goldberg Ultimate Build 60 size by twn[/link]

I wouldn't use the kit supplied mount for a 4 cycle ys. It is designed for a 60 2 cycle.

Thanks twn,

I made my own firewall from 1/4" aircraft ply. The master plan was to mount the elevator serovs in the tail. A couple ounces in the tail could make a big difference. I was just wondreing with all that weight on the nose and to push it out another inch would it be worth it. I have some other mounts that my work just wanted to cut down on the vibration. I did read your post, got some good tips thanks.

maekju