Briggs and Stratton 6.5HP Compression loss

LD1 · Oct 2, 2013

An odd thing happened this morning.

Split a load of wood two days ago. Cut a load yesterday and went out to split it this morning, and no compression at all.

Drug splitter into shop and confirmed, absolutely no compression.

So I started tearing into it and the intake valve was stuck open:confused3: Valve stem and bore were not scored at all?? So I tapped it closed with a mallet, worked it a few times and it seems smooth as silk. Put it back together and everything runs just fine.

Just wondering if anyone else has experienced this?

I guess I wont get out of splitting wood today afterall :laughing:

Oh, its a Briggs intek 6.5HP on a TSC huskee (speeco) splitter that is about 15 years old and has split ~15-20 cord of wood per year since new. Other than the gas tank leaking at the seam, this is the only issue out of this motor.

oldnslo · Oct 2, 2013

LD1,
possible long shot but could the engine have some how run backwards a hare on shut down forcing a piece of carbon down into the valve stem guide. Like most I have seen carbon get on the seat and hold them open but have not seen one jam the valve stem like that though.

quit sloughing off and get back to splitting wood

LD1 · Oct 2, 2013

Thats possible and I never thought about that. Soemtimes the hydraulic valve dont kick out of return, and I dont catch it (cause I ususally am hitting the kill switch right as it fully returns). This causes it to shut down under hydraulic load???

I did go split wood for about 30 minutes, shut it off to stack, and it stuck again when I went to restart?????

So now I am puzzled. ITs got pleanty of oil and getting it up top as evident by the few ounces that runs out the valve cover when I take it off???

It only takes ~5 minutes to pull the cover and free it up, but it might just be time. It was split well over 200 cord of wood.

I do have a 16.5 HP electric start just waiting to go on if this motor dont shape up. I will likely upsize to 22gpm pump while I am at it and double my speed from the current 11gpm. But will have to figure a way to double the oil capacity too.....

RandyT · Oct 2, 2013

I suspect that there is carbon stuck to the valve stem causing it to stick when the engine is stopped. You may need to remove the valve from the head, and clean the carb off the valve, as well as finding a way to clean the valve guide.