My brother has a '07 DR650 that he had stored for the past 5-6 months, with fuel stabilizer in the fuel system.

Started up and ran fine, for about 3-5 minutes, than quit.

After some cranking, it will re-start, but only runs for a short time.

We drained the float bowl, fuel was clean. Removed the in-line fuel filter, looked clean, left it out to totally rule it out. Also removed the fuel cap to see if it made a difference-thought possibly the tank wasn't venting through the cap?

Still no change in running.

While the engine is running, the bike drives fine, no loss of power.

Any suggestions on what could be the cause of the problem?

It sounds like the fuel in the float bowl isn't being replenished fast enough. Have you tried using the reserve or prime setting on the petcock? Maybe there's some limited blockage in that area. I'd also check the vacuum line for the petcock, maybe it's kinked or there's some kind of partial blockage there. Also make sure the choke is opening and closing properly. My bike won't idle at all with the choke on when the engine's warm.

If the float bowl is full of gas, then the petcock, vacuum line, and needle valve should be fine.
However... if the bowl fills immediately after the bike stops, then you wouldn't know if there was a problem like the needle valve sticking and then it shakes open when the engine stops (or the petcock opens when the engine stops, etc.). I've seen some weird stuff happen, not specifically on a DR650.

Might just be worthwhile to go through the routine of cleaning the carb, maybe change the pilot jet with a new one. Stabilizer is a great thing, but it isn't perfect; you can still get varnish and gunk if the bike sits long enough.

Is the battery charged?

soaringman said:

Thanks for the replies, will need to check the things mentioned.

Regarding the battery, are you saying a battery that isn't fully charged could be the (or part) of the problem?

Yes, when my battery was recently dead the bike kept trying to stall and did at lower revs.
I put it on the trickle charger for a couple of days and now all is good,

If your bike has electric start and it cranks over fast then I wouldn't think that is the problem

My brother called, said it will run on "prime" so we'll have to pull the petcock out and check further.

How about reserve? If not then the vacuum hose to the petcock or the petcock itself.

Bike seems to be starting and running fine now.  

This is my brother's bike, and he had added some Sea Foam to the fuel yesterday morning, shook the bike as to mix it well with the fuel in the tank and as mentioned had put the petcock on prime , not sure if he tried reserve or not as well, but all seems fine at this point.

Here it is March 13th, 2012 and the bike is doing it again, this time it will run fine  with the fuel valve set to "prime" or "reserve" but not in the "on" position.

Should we be looking at the petcock as the issue?

Edited by xcsp, 13 March 2012 - 04:59 PM.

 xcsp, on 13 March 2012 - 04:58 PM, said:

Either a bad diaphragm in the petcock or a disconnected/holed vacuum cap to petcock hose.

If its hooked up right it sounds like another petcock bit the dust. I would recomend going to a manual version. If the bike is sitting a lot, treating the fuel is not enough. Always drain the carb too and fill the tank full with a good quality stabilizer.