Why is my KLX250s hard to start after it sits for more than a few days?
 

Something slightly annoying about an otherwise amazing bike is starting. If I park the bike and forget to turn the petcock off and drain the fuel bowl, it becomes very hard to start after a few days to a week.

Had this happen again today after forgetting to switch off the petcock a couple weeks ago. Even a shot of ether wouldn't light it up.

Is this a design flaw with the OEM carb? Is it something else entirely? Never had this "bug" with any bike until this one.

had the same problem on my old scooter
turned out the float did not close properly, causing it to ever so slightly flood the cylinder so it was hard to start.

The factory size starter jet in this carb is a little on the "too small" side. It makes the cold starting success require everything in the carb to be perfect...the right size pilot jet for your conditions...the perfect fuel level...good fuel...etc.

This is partially a result of emissions requirements and/or poor starter jet selection size at the factory. Not all KLX's exhibit this. Those of us who have had this problem just drilled out the starter jet to the next size...because I don't think this jet is replaceable or available. While it sounds like a radical modification, it's simple and it works. Kawasaki recommended this on some of their street legal models to the mechanics at some dealerships, though you'll never see this in official memos.

I forget the drill size used now for our KLX, but hopefully someone will chime in with the number.

Obviously you could have some other problem causing this symptom, but this is the first thing that comes to my mind...especially if the bike has always done this routinely.

You don't have to shut off the petcock and drain the bowl for under a week, but you do have to drain the bowl some before starting. it's not the carb, it's our modern fuel. The fuel in the bowl draws water from the bowl vent tube. Likewise, the fuel in the fuel tank draws water from its vent.. You probably know, water sinks to the bottom of the fuel tank and bowl..

Fuel may be part of it for some folks, but I run non-ethanol nearly exclusively and had the same hard-starting problem before drilling the starter/enricher jet. Drill to 0.018-inche. It's just slightly larger than the current jet size and you'll be removing a very small amount of material.

Or, other methods:
Shut off the petcock and run some of the fuel out before shutting off the motor. About 1/2 of a block was sufficient for me. The bowl doesn't need to be completely drained; a little fresh fuel when opening the petcock helps.

Lay the bike down on its side and lift it back up. This causes an overflow from the carb (may be easier than opening the drain valve).

Shake the bike around when hitting the starter. Apply the front brake and push/pull on the bars to get a good up-and-down motion.

The Ohio gas blend will cause starting issues if left sitting for more than around 2 weeks or more. I have the jetting and drilling all done along with no compression release and the MCM, still same issue. My KLX650 has problems firing the junk after only around 5 days. It is the gas. The solution is to run it low with the petcock turned off, the gas in the tank has such a huge volume compared to the ability to evaporate the aromatics injected into the blends now compared to that of the float bowl that it won't go bad over a long period. That small amount in the carb just goes bad.

Don't know about Idaho though.

Idaho is a terrible place.
Don't move here.

:D

This is a very old issue "solved" at least 10 years ago.. I recently read one of Deej's old threads where he experimented until he found the solution - Fuel left in the bowl a few days or more.. History, love it or repeat it..lol

https://www.kawasakiforums.com/forum...rt-posts-8652/

Scott, I know you're aware it was the starter jet, but after a little Rainier, I know how it goes.:D

At least you have good potatoes. Make french fries or bake one and a slab of beef and all is good with the world for a while.