Why is my valve sticking? Go-kart Briggs and Stratton?

Question

We cleaned up the old go-karts yesterday. They ran only for a few minutes while we did a test run just before dark.

Then, this morning, on the first pull we hear a clank, and it was a BIG sound. We continued to pull it and it still had compression and no strange noise for about 10 pulls, and then compression was gone. We felt air coming out of the carb so we knew it was a valve problem. We got in there, and sure enough it was. After some cleaning and lubricating the valve came closed. We turned over the engine and watched as the valve was pushed open and CLANK! Again, it was stuck open.

Heres me question, why would the valve be stuck so bad? The sound is clearly caused by the MOVEMENT of the valve, and not something breaking.

What "kind" of stuck is this?

Answer 1

look under the carb.....on the side of the block...you,ll see a breather...remove it....then you,ll see the valve spring,s& retaining washer,s...remove the washer by prying up & to the side....it will fall loose....the valve can then be removed..remove any burr,s & check the valve guide....use ......B & S lead complex valve lubricant & reinstall......you will need a valve spring compressor to do this.....available at your nearest power equiptment dealer.....the valve guide can be replaced....but this is best left to a machine shop.......good luck!

Answer 2

I woudl think your valve stem has got a bit bent. Take it out and check on a flat surface like a sheet of glass or something like that. And when you have the valves out be good to check for carbon in the guides as well as that may stick.

Good luck

Answer 3

I think you're out of engine oil.

Boat anchor.

ADDED:
If it's OHV, the piston hit the valve and bent the valve stem.

Answer 4

clogged mixture, try some wd40 on it. your spark plug might be fouling