Noob with a question

[zjguy721]

Picked up a 2000 DRZ400S this weekend. Pretty much stock as far as I can tell, but I'm having an issue.

It will usually start up the first time when it is cold. Once it is running, however, if you shut it down it won't fire back up. Turns over, but won't fire. Did it every time this weekend. Let it sit overnight, fires right back up.

I've had quads, jeeps, etc before, but this is my first attempt at a bike. Is there something I'm missing? If not, would a carb teardown be in order to see whats inside?

[rideitfixitrideit]

Check for gas in your oil, if so you have a bad petcock. If no, then check your valves. It would be a good idea to check them anyway at least to get a baseline.

[captbalz]

What you describe is a symptom of valves getting tight.

Could also have to do with smog and carb issues. Don't know if your bike has a smog canister on it. I'm in CA. so mine had all that crap on it that made it flud, vapor lock, and not start. Removing all that helped mine a bunch.

How many miles on your bike?

[Craigo]

When re starting does it start if you use the choke.?.

Valve clearances may be in need of adjustment..

[zjguy721]

Doesn't make a difference if it is choked or not.

Just over 8k on the odometer. AFAIK, its never been taken apart, but of course that's the word of the POs.

OK, here's a question. How difficult is it to take apart and check for things? Again, first time with a bike, just not sure what I would be looking for. Should I just take it to the shop and have them give it a go over? Won't be riding it until the spring anyway.

[npm]

Here's the write up on checking and adjusting valves https://www.thumpertalk.com/forum/showthread.php?t=813179 in the FAQ sub forum https://www.thumpertalk.com/forum/forumdisplay.php?f=397 lots of good info there.

For gas in the oil pull the dip stick and smell, it it smells of gas at all change it. Do you know the last time the PO changed the oil? If you don't know I'd change the oil and see how much comes out. Should only be 2 quarts, more if you have gas in the oil. Change the filter and add 2 quarts of 20-50 full ester synthetic (just my opinion, not trying to start and oil debate). Oil change link from the FAQ link above, check the screen as well https://www.thumpertalk.com/forum/showthread.php?t=665513 At the bottom of the oil change article is a link for checking/cleaning the screen.

The vacuum petcock on the S can fail and allow gas to run into the carb, through the shut off needle/seat and into the crankcase. It can also fail and leak into the vacuum line on the petcock and from there into the carb. To check, set the petcock to "ON" and pull both gas and vacuum line and look for drips. The only position that allows flow without the engine running is PRI, you don't have the petcock set there by accident do you?

[Craigo]

Can the PO provide you with any service documentation.....like even the shop he took it to?..Some service history of the bike could prove useful....