My 450ES won't idle. It starts with the choke, but when you go to idle, it idles then a loud ping occurs and it shuts down. It runs good above idle speed. I've checked the carb, I was going to check the timing chain. Any ideas?

 

More often than not it's a plugged low speed jet. It is such a small hole that they are hard to clean. At idle it's the only path for fuel to flow. Since you say that it runs fine off idle I would re-check the low speed jet.

 

I had the exact same problem on my 2003 450ES and it took me like 4-5 time of cleaning the carb to finally see that I was over looking a piece of dirt in a jet. After I cleaned it it runs like a champ! Get a needle or something the same size as the jet holes and run it through every hole to make sure they are clean!