2003 crf450r

[two.smoker]

Help! My Honda CRF450R will not start! We were at Pismo Dunes and it started and ran perfectly until I let it sit for about an hour and there was gas under the bike coming from the over flow. I tried to start it and nothing happend. We took it to the beach and pull started it and after about 2 minutes of pulling, it finally fired. I rode around for a while and killed it on accident and it would not start back up. We came back home and I took apart the carb and cleaned it and it still would not fire. I don't know what else to do. Please help. By the way we also barley got it rebuilt and the bike only has about 2 hours on it. I wish I had my two stroke back![emoji24] [emoji23]

[TheSnide]

Those are the exact same symptoms of mine when it had shot valve guides and valves would stick after a day of riding

[two.smoker]

Intake or exhaust?

[TheSnide]

Exhaust....

[jblob]

Sand riding makes valves more likely. Either because of a bad air filter letting sand in or just how hard you run the engine in the dunes. If you have to pull start and the carb isn't clogged up it's probably valves. Did you triple check that your timing marks are all lined up?

[two.smoker]

I did not rebuild it myself but that's something I'll look into

[HRC27]

How are your clearances?

Edited November 19, 2017 by HRC27