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#1 farmer john OFFLINE  

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Posted April 24, 2015 - 05:49 AM

I have a reasonably new 5 hp briggs and Stratton on a rototiller, its has the type of carb attached to the gas tank ( how I hate them) any ways it would not start, I pull of the air breather and give it a shot of quick start,, fires right up, ok dirty carb, take off the carb and the gas tank, clean out all the crap, reinstall, now it wont fire/start even with quick start, check the compression, "0" pull the plug I can see both valves moving freely, about 1/2 in stroke so I don't think its a stuck valve, hope its not a hole in the piston, but I have heard on you tube there is a decompression valve of some sort on these motors to aid in easier starting, do these cause issues, any thoughts before I start a tear down later today
. any easy fixes. thanks john

Edited by farmer john, April 24, 2015 - 05:51 AM.

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#2 JDBrian OFFLINE  


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Posted April 24, 2015 - 07:02 AM

Could it be carbon causing a valve to be stuck open. I've had this happen on a HM80 tec. No compression. I thought the motor was shot, but looking in the plug hole I saw a lot of carbon. I sprayed in some WD40, turned it over a bunch of times and then I had compression. The engine eventually ran after a carb cleaning. It had been sitting for 4 or 5 years before I got hold of it. 

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#3 classic ONLINE  

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Posted April 24, 2015 - 10:09 AM

I had no compression in a 9hp Briggs due to carbon flakes getting between the valve faces and seats.

Edited by classic, April 24, 2015 - 10:12 AM.

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#4 petrj6 OFFLINE  

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Posted April 24, 2015 - 03:16 PM

   If the carb is in the tank like that you will need to give it a bit of prime after every time you take the carb apart.  when you pull the carb out and clean it the little bowl on the inside get emptied out and that is where your carb draws fuel from, with that empty their will not be enough vacuum to re-prime the system as you pull start on it.  it will need to run good for a sec to get that little bowl filled back up.  I had the same trouble on my air comp motor till a friend gave me the heads up on it.


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#5 holdenboy1960 OFFLINE  

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Posted May 02, 2015 - 06:40 AM

the stopper wire is connected to the side of the ( behind ) carbie housing , check the stop wire is connected to the stop connector & is not touching any thing to short  the spark out