briggs 24hp only runs with one plug removed

[pinevilleoxbow]

guys

looking for thoughts on my situation.
briggs 24hp platinum on a craftsman zero turn

randomly mower quits while cutting. 200hours on it.
i pull it back to the shop and do some quick checks.

determined that if i pull the right plug completely the motor will fire and run on the left cycylinder.
will not runn if the left plug is pulled and right plug is in
done a compression check and have both 150psi
swapped coils for the hell of it.
checked for spark and have spark on both sides.
have changed plugs

right side seems dry.
sprayed some started fluid in it just to try. no difference.

 

[Fish]

Remove the valve covers and take a peek...

 

[Fish]

You will likely find a loose pushrod.

 

[pinevilleoxbow]

baw, you were exactly right!
the bottom push rod was dislodged from the retainer.
i need to find a guide to reinstall. and i guess go buy some feel guages
thanks

You will likely find a loose pushrod.

 

[pinevilleoxbow]

You will likely find a loose pushrod.

@fish

0.04? Valve clearance?

 

[Fish]

http://outdoorpowerinfo.com/engine_specs/briggs_valve_gaps.asp

 

[pinevilleoxbow]

http://outdoorpowerinfo.com/engine_specs/briggs_valve_gaps.asp

Thanks. Fixed and fired right up.

Got a little tick to it now. I’m just going to send it for now and jack with it later.
I guess change the rod the spring and rocker? But then I’ll have to jack with removing the head. On second thought. Full sending it. No time for all that.

 

[PTmowerMech]

A tick? The valve cap was still on there when you adjusted it, right?