Hey everyone,

I have a stock KLX250S... all stock except for 3 gal IMS tank, bark busters, hand warmers... Rode it all across US and Canada, death valley... great bike!

So about a month ago after taking the bike in for 20000km service, I left the bike for a week and it wouldn't start... Engine is turning over well it seems but no ignition... Tried the usual, choke, petcock, fuel... no go... PS I did put fuel stabilizer in the fuel. It's been about a month since I rode it.

Put the battery on a tender, checked voltage with no load and under load (12 without load, 11.5 under load)... All good.

Pulled the spark plug and tested it (by firing ignition with the plug grounded to the motor frame...)... there is a good spark. Actually the plug was just replaced.

So there's a spark, next I checked fuel... Removing fuel hose from tank, yep, it flows...

Drained carb bowl. Still won't start. But now there is no fuel in the carb bowl. So I open BOTH the fuel petcock and the carb drain valve, and nothing comes out of the drain hose... The carb bowl appears to be empty...

I fire the ignition and even with the starter turning, no fuel comes out of the carb bowl drain hose...

Here's my thinking... there's fuel going out of the petcock down to the carb... unless there's a block in that fuel line, I'm assuming the fuel flow reaches the carb inlet... but then why isn't there any more fuel coming out of the carb bowl, now that it's drained?

To me that sounds like a stuck float valve... I'm just a beginner at this though.

Your guys' thoughts?

Do I need to remove the whole carb--- that looks complex, lots of hoses and connection points... is there something relatively easy that I can do here?

Thanks!!!

Mark

 

Try tapping the float bowl with the plastic end of a screwdriver fairly firmly but not too hard. That should free the stuck float, which is what the problem seems to be.

 

Your float is stuck.
Easy solution: Lay the bike on it side on the ground for 5 seconds with the gas on. Usually this will fix it. Use the choke full on, don't turn the throttle until after it fires.
Suggestion: Always run the carb dry before turning off. Especially if your not riding for a while.
Alternate solution: Hammer!

 

OK guys,

Tried laying the bike on its side.
Tried hitting the carb not-too-hard with a hammer.
I got it started but it only runs for like a minute. Then dies suddenly.

My guess is that not enough fuel is hitting the carb bowl to keep it running.

I open both the fuel petcock and the carb bowl drain valve and, after the carb drains (steady flow out the drain hose) then I only get a drip-drip-drip... I checked and there's ample fuel flow to the carb inlet. So why is the flow rate out of the bowl so low when the drain is open?

My guess is that something with the float still being stuck... Not sure what else to do other than pull out the carb and have a look at the bowl/float assembly.

Do you guys have any tips on how to pull the carb? Or is there something easier you can think of?

Thanks !

Mark

 

Only way to do it is to do it.

 

Make sure the vent tubes are not obstructed - if they are fuel won't flow adequately into the float bowl. I would agree that pulling the carb and giving it a good cleaning would be well worth the effort.

 

Did you run the bike after the service work? You might want to check your fuel lines under the tank for kinks if it was removed. (between tank and frame mounted petcock) When I purchased my '07, the original owner said it seemed like he had to put the fuel petcock on reserve much sooner than before. I wasn't too interested in running out of fuel on a ride, so I got into it and found out he had the fuel lines kinked in the area I mentioned. He had re-jetted after installing a new muffler, and kinked the new fuel lines he had installed. I replaced them. Routing and length are critical to proper flow.

You just had it serviced, so you can rule out engine problems. If you have fuel, spark, and air, it's supposed to run! IMO, It's got to be a problem with the fuel delivery. My two cents. Good luck!

PS- I don't believe you'll have to remove anything to check the fuel lines for kinks. I didn't on my '07.

 

Good advice given so far. If none of those solve the issue, try the following before pulling the carb. Get some Berryman's Chemtool B12 in a spray can. Disconnect the fuel line going into the carb. Slowly fill the line with B12. I recommend using some cheap Harbor Freight or other nitrile gloves as B12 is not that great for your skin...also watch your eyes for spray splash with this stuff. Push the fuel hose back on to the petcock with the fuel off. Let it sit overnight and see if you get anything out of the drain vent tube the next day. If you do, turn on the fuel petcock and see if you have fuel flow now.

Lastly, drain the fuel bowl of fuel again. Spray B12 into the fuel line again, insuring that B12 dribbles out of the drain tube. If it flows, close the drain screw and fill the carb and fuel line with B12. Let it sit overnight. The next day drain the B12 and let the carb fill with fuel. Check results. Over the years I've lucked out several times and beaten the traditional carb pull and clean by doing this procedure. Worth a try. Chemtool B12 is pretty good stuff.

 

^ Nice one Thad.

 

If not already suggested remove gas cap and try to start it as if the vent is plugged it will act like that.