Leopard engine mount threads

ryan wagoner · Posted: Sun Oct 14, 2012 12:32 pm Post subject: Leopard engine mount threads

Last night one of my Leopard engine mount bolts pulled the threads out of the case of the motor. To repair it should I drill the threads out and tap and bigger thread size in or heli-coil it to the same size thread it was 8x1.25.

ryan wagoner · Posted: Sun Oct 14, 2012 12:39 pm Post subject:

Also this is the second time the bolts have backed out of the case, is it a vibration problem with the stock mount or am I not lock tighting them enough or tightening then enough. Would an Odenthal Motor Mount help vibration or the problem at all?

jeff grose · Posted: Sun Oct 14, 2012 12:50 pm Post subject:

do you NOT have the steel vibration plate, if not you SHOULD Exclamation

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ryan wagoner · Posted: Sun Oct 14, 2012 1:16 pm Post subject:

Yes I do have the vibration plate!

Dan Haynes · Posted: Sun Oct 14, 2012 1:49 pm Post subject:

What mount? We had that problem once but it was on the Arrow motor mount and I had put a washer on it and it wasn't sitting down far enough so the bottom half of the mount wasn't sitting flat. The bolts loosened up on me on two occasions. Took the washers off and haven't had that problem since.
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ryan wagoner · Posted: Sun Oct 14, 2012 2:32 pm Post subject:

To my knowledge its a factory Leopard mount. I just replaced the bolts to longer ones because the race weekend 2 weeks ago the same thing happened but it was worse. They had lock tight and they were safety wired!

Steve O'Hara · Posted: Tue Oct 16, 2012 11:26 pm Post subject:

Ryan,

Don't drill it out to a bigger size. Go here and buy a thread repair kit...
http://www.timesert.com/html/mtrcsert.html

I think the threads are 8x1.0 but I am not sure... better check that or someone here will verify or correct. Might be 8x1.25
The repaired thread will be stronger than original.
The TimeSert kits are very high quality products and easy to use but you will need to be very careful when drilling to clean up the hole before tapping that you keep the drill square to the bottom of the case and do not let it make the hole any deeper. Best to use a drill press for the process if you have access to one... but hard to hold the whole motor upside down on the drill press table.
When I have to repair threads in a hole like the bottom of a motor where it is not possible to use a drill press or mill I make a "drill guide" that sits on the flat surface around the hole and keeps the drill bit squared up.
Steve O'Hara

Pirooz Javan · Joined: 16 Apr 2010 Posts: 45

Ryan,

I had this problem happen to me because I think i tightened too much. Use a torque wrench and follow the manual. Surprisingly, its not as tight as you would think. Haven't had a problem since (I do run with the vibration plate)

Pirooz
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