# fire breather st16



## nev (May 7, 2011)

My son and I were given an st16 from a local junk yard to turn into a pulling tractor. After some inspection and trouble shooting we were able to get her running only to find the under lying problem responsible for her dilevery to the scrap yard in the first place. The tractor fires with the exaust valve open. O first things first its a tec oh160 we installed new valve guides and lapped the valves which looked new as did the head gasket. the cylinder had been honed. the fly wheel and key are in good shape the trigger pins are set to the proper height. somehow the timing is off so we were able to borrow a working solid state ignition to see if that was the problem. It was not. The valves are set to the proper clearence .005 in/010ex. Armature air gap .008 and to top it all off we pulled the cover only to find the timing marks line up. Oh the compression release is not stuck. Can anyone help me???


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## Hoodoo Valley (Nov 14, 2006)

..........Lifter stuck?:lmao:


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## nev (May 7, 2011)

No, everything is good on the top end while we had the top off we installed new guides


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## dangeroustoys56 (Jul 26, 2010)

For kicks, try changing the flywheel key- ive had some that looked whole but were actually split changing the timing on the fly.


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## nev (May 7, 2011)

I'll try that first, at this point I'm ready to start replacing things that could cause slight symtoms and maybe a combination can fix the problem.

I'll keep you posted
Thanks


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## nev (May 7, 2011)

We bought another good running engine took the muffler off and it did the same thing. I guess they just run that way. I've never seen anything like it.


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## jhngardner367 (Apr 5, 2011)

Yeah,that'sthe comp release working.It's supposed to close the valv after the engine has reached 300 rpm,for easier starting.


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## jhngardner367 (Apr 5, 2011)

Hey, just a thought...check and see if the pushrods aren't switched around!One should be a darker color than the other,and there's a slight difference in length,as well.


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## nev (May 7, 2011)

The origional engine is on the shelf. I'll rip it apart this year but before I do I'll try the pushrod thingy.

Thanks

Nev


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## dangeroustoys56 (Jul 26, 2010)

I know when i ran my 'modifed' murray around that had a twin 18HP briggs on it and 'shorty' headers ( stock pipes to the factory muffler- muffler removed) - thing popped horribly when letting off the gas - most small motors like some back pressure, the 12HP teccy on my 85 LT12 craftsman would barely run when i ripped the muffler off ( on a branch).


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## wjjones (May 28, 2010)

Might try to open that gap up to .010


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