John Deer TX gator backfiring issue finally solved

I've been chasing down a backfiring issue for weeks last season. I noticed had that I had not blogged about it.

Found only a few pictures on my phone. 

This machine had lost the exhaust right at the head once. Originally thought maybe A burnt valve.

Checked everything in service CD. Replaced fuel filter, fuel pump, made sure throttle valve closed all the way. Even pull carb and cleaned up and check float setting. Lastly, I replaced the coil figuring it was breaking down once it was hot. 

It would only backfire after 5 or 10 minutes and on long runs downhill then letting off on throttle. 

Nothing worked, problem just remained the same no matter what I did.

So I decided to pull the engine and removed the head to see if there was a burnt valve. 

To my surprise everything looked great.  

I assumed the engine was basically as the club Car until I seen this reed valve. Following where the passages went it seem to be some sort of PVC system. Exits out by the valves. Or could also be what gives the fuel pump its pulse. 

The reed valve looked damaged so decided to replace it and backing plate.

Green circle above shows where it's located.

    

Side view of reed valve. Used a bit of red loc-tight and torqued to spec and made sure it was over the port. 

After reassembling and adjusting valves etc. Surprisingly has never backfired since. 

It was a real head scratcher and thought to post it incase it's one of those one-off issues that come across once in a lifetime.