My 09 KLX 250S (stock) bike ran flawlessly then sat for about 6 months with fuel off. At 80-90 degrees ambient air at sea level with new fuel it starts on full choke but takes maybe 5 minutes before it will run at all with choke reduced gradually to the off position. Still will not run with throttle at zero unless idle is set high. There is a hesitation (bogs down) when throttle is opened (more pronounced when opened quickly) until higher revs are reached then it runs pretty smooth but when I back off the throttle it acts like it's sticking open (continues at high revs with throttle closed for 5+ seconds or more). Throttle cables are good and not sticking at all! I see no fuel leaks, I get no high temp light but sense the bike is running hotter then it should (possibly lean)? Plug looks fine, not fouled or burned. Cleaned and oiled filter and no change (did not seem dirty prior to cleaning). I have the carb off the bike now, any suggestions on where to start (replace fuel line? clean carb? replace any carb parts?) Thanks for any help that points me in the right direction.

 

Starduster, welcome to the forum.

Unfortunately you are needing a complete cleaning of every "circuit" and component inside your CVK. Perhaps difficult for you if you have not done such a thing before and/or don't know the names of the above items.

Just know that if you intentionally or inadvertently cut corners during this process, and miss cleaning the circuit/component that's causing most of your problem, you'll be doing it all over again until you "get it right". There is also significant errors that can "happen" during reassembly and reinstallation..

Perhaps this thread can help - https://www.kawasakiforums.com/forum...s-fixes-43146/

 

Agreed, seen it hundreds of times in the bike shop where I worked. The gas in the float bowl evaporates leaving residue that then flakes off and clogs the primary circuit. The new gas can turn it to goo that just can't be easily blown or sprayed out with carb cleaner.

If you have the skill, take the carb apart then take the parts in to some bike or car shop with a carb washer or ultrasonic machine. They can work the cleaning solution into all the passages. It is worth doing. Then reassemble.

I leave my gas on, keeps fluid in the float bowl. If there was ever crud in the float valve it would overflow and obviously I'd know it. Then when I go to start the bike I drain the gas first. Never have had a clogged carb doing that. With the couple bikes I had that used vacuum petcocks I drained the float bowls. Thing is the one time I did that on the 650 the float needle seized in the body - tear down remove and repair.

 

Thanks for pointing me in a direction KLX678 and klxster,

Since this is a very low millage bike (under 6000) and began after time sitting unused and not after a disassembly or carb adjustment I think it's unlikely to be a diaphragm seating issue or a float level issue so I will try a comprehensive self carb clean first. If after reassembly I'm still having the problem I'll try a shop carb clean next.

 

I found some visible debris down in the pilot jet perforated tube, Could that cause the symptoms I was experiencing?

 

Yes. But if the pilot jet is clogged, it's not going to be the only item clogged. You certainly need to check the emulsion tube - its the item the main jet is screwed into, don't forget that the needle jet sits on top of it and may fall out..

Actually, as before, you need to clean every circuit and every part..

 

For sure, I have c9om-poeatly disassemble the carb and am soaking it over night. All components, paths, tubes are being inspected and cleaned. The only visible debris during the disassembly though was inside the pilot jet. It looks like some kind of fibrous material, almost like like thin web like fibers inside the jet.

 

Spiders!

 

Haha Yea maybe. Guess it did sit too long! Must have crawled in a overflow tube or maybe a valve was open and it came in via the tail pipe.

 

If the gunk is in the components, jets and all, then it is also all the way down in those tiny passages from the float bowl to the carb throat. That is a problem area. They are so tiny and inaccessible, the reason why I said it is best to have the body washed out in an ultrasonic or carb washing machine. It's like using a real washing machine versus kneading your clothes on a rock. One just does a far more thorough, better job. Less frustrating too. You do the labor, they just wash the body and bigger bits if you want.

Like I said, I've seen it many times over. It is extremely hard to get into the tiny passages with spray and metal wires can actually damage inner surfaces that would affect flow. If you decide to try to run something through the passages use monofilament fishing line instead of wire.