Briggs 550 engine - push rods not moving

[waylonJ]

I have a 5 year old newer Briggs 550 (about 5hp) single cylinder engine I could not start. I checked compression and it's zero. I pulled the OHV valve cover off and saw little movement in the valves nor the push rods. This engine has two thin push rods which push up the rocker which in-turn applies force to the valves to close them.

I decided to pull the head and the cylinder looks very good and well oiled. The push rods are confirmed to have very little travel in them. It was not really enough movement to force the valves to close. Both valves seem to have the same limited movement. The push rods are not attached to anything and can be pulled out of the cylinder head with ease - I am guessing this is normal and they should not be affixed in any way. There is an adjustment nut on the rockers and the nut is all the way tight. Not sure if this is how to adjust the clearance or not.

I would assume the crankshaft lobes cause the rods to move in and out - right?

I can post of video if it would help.

 

[Rivets]

Are you saying that when you took the head off, the valves were stuck open? The pushrods do not close the valves, they open them. The valve springs close the valves. Please post back and explain what you mean, with engine numbers.

 

[waylonJ]

Hi Rivets - thanks for the response. I loaded a pretty bad video of me hand turning the engine to show the lack of movement in the valves. The rocker posts are threaded and appear to allow you to tighten the nut in order to eliminate the slop - perhaps it intended.
Please let me know if you need more info. Thanks again!

The valves are fine and can be opened by pushing in with thumb - no issues.

 

[Rivets]

You need to adjust the valve clearance to make it work properly.

 

[waylonJ]

As a follow-up, I set the clearance on the valves and did notice there was movement in the push rods which did seem to close the valves. I put things back together and first pull, she fired up! Thanks very much Rivets!

I got this used as a non working mower - I have no idea how the valves got so loose.

 

[Rivets]

I got lucky again. Thank you for letting us know the results. Most of the time people never get back to us.