Hi
I am going to replace my plastic mount by the hyde A type mount, the engine is YS-110 and from what i read on the manual
it's suggeted to reinforce the firewall from the back side... !
now my firewall is not so robust but it hold the forcess till now.... and in order to do so i will need to cut the airplane... as i have no access to the backside of the firewall. is there other method how to reinforce it ? also if i will use nose ring do i still need to reinforce the firewall ? .
in addtion it's written that since the engine is going to shake there is need to make sure there is enough room for the engine parts that going out of the cowl ( like the main needle in my case ) is that so ?

thanks,

I just installed this mount / engine on a Sig Mayhem. I did nothing to the firewall and saw no reason to do so. After all the mount is supposed to eliminate the vibration forces ?? I was prepared for a lot of shake also - never happened. It moves a bit at idle and when you first hit the throttle but barely noticeable. All in all I like this mount. I also replaced the plastic mount and it is now much quieter / smoother with no ill effects.


I just reread the instructions and the ONLY place it says to reinforce the firewall is IF your using the ARI mount which incorporates a nose ring. Your using the "A" mount which does not. Your good to go.

Thanks
what engine you are using ?

also what about the throttle pushrod ? i am using direct 2-56 metal pushrod
is the fact that the mount will be shaking now going to cause extra vibration on the throttle servo ?

Thanks,

A YS 1.10

That's a good question. I'm using a plastic rod which will allow a bit of give. I have noticed that since I've gone to this mount ( about 10 flights ) I've had to increase my idle rpm's in order to keep the engine running at idle. This is no doubt because of the shake at idle.

Maybe someone has a fix, like a spring loaded clevis or something ?? Anyone ??

Hi Don,
My fear is that those shakes will cause some servo failure or the throattle are screw will get loose, and then
there will be no option to bring the engine back to idle till the big bang..........
which will break the spinner or the entire engine in the worst case..

maybe someone have idea how to minimize it.

I can tell you that I have another plane with a YS 140 in it and an ARI type mount with a nose ring. This engine moves waaaay more than the 110 / A mount . It has the same type of throttle hook up and has 100's of flights with no problem. I'm not worried about it. Most of this movement is rotational and not back and forth.

Thanks Don

We fly hundreds of flights every season with Hyde mounts in 2-meter Pattern planes. No major servo problems that I know of. A word of caution though: I wouldn't use a cheap mini servo - mostly because they're direct drive. I've had that type of servo (HiTec HS-81) fail in a 40-size plane when used for throttle. If you use a good precision mini or standard size indirect drive servo, (the pot is NOT attached directly to the output shaft) you should have no problems at all. Some guys mount the servo directly to the mount. That way your idle speed doesn't change when the engine shakes. I haven't tried this yet but I may soon.

John Pavlick
Team Black Magic, Tech-Aero Designs