r/dr650 • u/blue_arrow69 • 3d ago

Chasing down a carb issue..... What are your thoughts?

Let me preface by saying I have an OEM Mikuni rebuilt kit coming tomorrow that hopefully sorts things out.

The bike starts right up with the choke and idles great when cold. After about 10min of riding I get some symptoms that seem like a fuel issue. It'll sputter at low throttle while in gear and then a loud pop when I pull in the clutch and twist the throttle. Then it'll either bog down or die unless I'm in gear and really on the throttle. I can't tell if it's starving for fuel or has too much.

When I drained the oil, it smelled like fuel. I figured maybe my float was sticking or the float level was off so I ordered a rebuild kit with hopes of that working.

The bike had been sitting for a few years before I scooped it up. I've had the carb apart twice and cleaned it with a good carb cleaner. The factory tank and petcock have been replaced with an IMS and supplied non-vacuum petcock. I've also adjusted the valves to the tighter end of the spec. Aside from that, the bike is completely stock. I'm running at 7800ft above sea level.

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u/Nouyame 3d ago

Float orings. That said, I rebuilt mine several times and they always leaked into the intake. A TM40 was the solution lol

1

u/TwistedNoble38 '00 DR650 3d ago

Float orings are probably tired. 

At that elevation you can probably step down the jetting from the stock settings.

1

u/Infamous_Tea_9965 1d ago

Same problem I had . Put in the o rings and float valve yesterday