N1061D

Instead of installing the stock/nylon motor mount for my Four *40,I have decided to install an OS mount for the .46AX.Question...the holes/blind nuts were already installed stock to match the nylon mount,which is adjustable.I am wondering if I will have to drill new holes to match the OS mount??I can't find any dwgs.or dimensions/specs on the layout of the holes for the OS......any of yall had any experience(s) with this particular situation????Thanks............

carrellh

My "limited" experience is that every brand is different. I'd be very surprised if the existing holes match any other mount.

BadSplice

My Feedback: (1)

Simple test... just hold the new mount up to the firewall...... if the holes dont match up, then you will need to drill new ones and install new blind nuts.

djr1007

FYI, some say it's not necessary, but I always push out the old blind nuts (put the bold in several turns and then tap lightly with a hammer), then fill the hole with dowel and epoxy. You will have to do this no matter what if the new mounting holes are any where near the old blid nuts.

N1061D

I was already anticipating re-drill/patch holes.......I was just hoping to get "lucky" once.It will all work out either way.The OS mount is in transit.It won't arrive til next week.We dont' have flying weather forecast for this weekend so.......stay home and work on the plane(s).........run the new engine in.......at least make some noise and burn fuel.
Thanks

KitBuilder

Is this the ARF? Mine kit version didn't have holed predrilled but it did have little dents where the holes were to go. I went with a different mount than the two piece that came with the kit and rotated the motor about 30 degrees as well. I just made sure the centerline was the same and it flies great.

N1061D

Yes,it is the ARF version.Pre drilled with blind nuts installed.According to USPS tracking data.....I might receive the OS mount today.Hopefully it will arrive and I can spend tomorrow in the hangar and finish.I won't be flying,we have bad weather forecast tonight/tomorrow.I will report how it all goes.

N1061D

Damn the bad luck......the OS holes are 1/2 hole off from the stock holes...and.....it blocked the fuel line opening in the firewall.....and.....blocked the pushrod opening....
To adjust would have meant too much modification than what it was worth......so..........I went with the stock mount for now....used the OS on the bench to run the motor in.
the.46AX ran well....however it being heavier than the .40LA/.46LA...by 4 oz. I have to add lead to the tail......she's nose heavy.

frenchie79

LEAD! don't do it, look for other ways like move your servos, battery ectt.. Add a lttle larger tail wheel. I used an AX46 with Dubro rubber mount system and needed no lead. Battery was behind my servos. Sorry to chime in like this, but that plane is great as light as possible with that motor and a 12.25x 3.75 APC prop.

frenchie79

Look at spinner weight, look at your tail wheel-maybe go bigger-1". Heres a shot of my 4* servo area. I just put a Magnum 52 in this winter after having an OS 46 and the latest an OS 40 FP. Picture shows the old battery mount behind the servos. Now the battery is at the mid point.

CustomPC

My ARF Four Star was nose heavy with a Saito .62 and i found that i could move the battery to behind the servo tray underneath the cockpit floor. I stuck some velcro to the former and and cockpit floor underside and then used some zip ties through the cockpit floor to keep it there. A strategicaly placed pilot hides the zip tie from view in the cockpit and also adds a little bit of tail weight.

N1061D

My problem is solved!!!!!! this being my first low wing plane I was balancing right side up......LHS guy set me straight and told me not to feel bad,he did the same with a Super Sportster years ago......I wound up placing the batt. behind the servo tray like Custom PC did and she balnced dead nut........UPSIDE DOWN this time.......no lead required.
The instructions book had a pic but no language saying to balance upside down.......needless to say I am relieved.All I have left now is trim scheme...I will post a few pix when shes done.Thanks for everyones responses and input.Rookie mistake......Lesson learned.