It's had a complete overhaul. Everything engine wise has been gone through, except the psb injection pump, by someone that knows what they're doing, which isn't me. I've put about 5 hours on the engine, tedding hay mostly. It's ran fine. I just washed it up to take it to our local show. I then started it up like normal and when I gave it some rpms, it made some loud popping noise. Will pop once or twice as the rpms climb then quit popping and run like normal. It did sit over night before I started it. Doesn't sound like a knock, more of a pop. Don't think any water got in anywhere, used a hose and hand washed it. Any ideas where to start? I'm awfully worried it's in the pump.