OS 105 Mounting Exhaust

[Trex_700N]

Ok everyone, I really am hoping someone can help with this. I have installed an OS 105 in my 700 and am installing the pipe right now. The pip that I am installing is the OS 105 power boost. The thing that I am running into is installing the exhaust that bolt the pipe to the engine. Is the engine suppose to be threaded in the block? If so are you suppose to run the bolts through the pipe side or on the engine side? It feels like I'm going to strip the bolt holes in the engine. Any help or advice would be appreciated.

[dchekas]

The bolts go through the pipe and thread into the engine on the 1.05.

[rcyoda]

Originally Posted by dchekas

The bolts go through the pipe and thread into the engine on the 1.05.

So it is supposed to use short bolts? (as you cannot use long ones because they will not bend around the pipe body )

[Raz0rSh4rp]

Drill the threads out of your crankcase and use the bolts from the .91. Otherwise you will break the crankcase in a crash.

[wjvail]

As others have said, the bolts go through the pipe and thread into the 1.05 case. This is backwards to most other OS engines.

[rcyoda]

Thanks guys. I fixed it with short bolts, as on first two photos. I would rather prefer not to drill-out the threads.

[Eury]

Originally Posted by Raz0rSh4rp

Drill the threads out of your crankcase and use the bolts from the .91. Otherwise you will break the crankcase in a crash.

This is the voice of experience. You may not want to go this way, but when you crash and have to replace a crankcase, you'll regret not doing it.

[jiminator]

I've ripped a crankcase apart on an OS .55. It has bolts that go thru the engine and thread into the pipe. Pretty bad crash though I could see with a more minor crash this could be an issue with the 1.05, just have to crash on the non-pipe side

[rcyoda]

Originally Posted by Eury

This is the voice of experience. You may not want to go this way, but when you crash and have to replace a crankcase, you'll regret not doing it.

So with long bolts through, secured with nuts, it is more likely that the bolts will break?

[Eury]

In my experience in a crash that hits that side, the pipe will bend and the crankcase will break if you have it threaded into the case. With bolts only the pipe bends.

[Raz0rSh4rp]

Not only are you likely to crack the pipe mounting face, it is even more likely that a hard crash on the pipe side will actually pull the threads out of the crank case and you wont be able to get a good seal or even mount a pipe at all.

[rcyoda]

I finally drilled-out the threads. Thanks for your advises guys.

[Raz0rSh4rp]

No prob, long live your 1.05