noob 2003 drz 400 s full yoshi dyno jet...issues

[yello400]

wondering what it means when bike cuts off after riding afew minutes ,only runs on reserve? it has full tank and only 1400 miles ,should i empty tank or turn up carb screw?

[Metalhead201]

if you took the tank off make sure both lines are on the petcock not just the one line. if its not that wait for other responders

[joey w]

like metalhead said check the vent line on the tanks petcock its the smaller hose that goes to your carb.

[yello400]

I thought maybe the pilot screw turned in would work ,but there doesnt seem to be one on it mukuni carb

[stringburner]

Sure there is. It's sealed w/ a brass plug on the bottom of the carb. You have to drill out the bushing to access it. If it won't run w/ the petcock in the "ON" position, it shouldn't run w/ the petcock in the "RESERVE" position unless it's low on fuel. Try it in the "PRIME" position. If it runs here, you have a vacuum issue. There is a vacuum line that attaches to the petcock behind the fuel line, and then it attaches to the carb. on the right side:

https://www.thumpertalk.com/forum/showthread.php?t=307435

That line supplies vacuum to the petcock, which is vacuum operated. No vacuum, no fuel flow.