Thanks Brian, in an age where most people don't care what other people think about them, I'm just the opposite.......Now if I could get LV and Iowa guy to pardon me I might get some sleep.....sorry guys.

 

You may say its your conscience keeping you up but I'd say its the 3 pots of coffee.

 

Yeah, try decaf during those coffee breaks. Hey, how about dumping some coffee into your airbox?

 

The hand over the exhaust pipe really works. It's was about 30 degrees and it fires right up after sitting a week.
Otherwise it the choke juggle deal.

 

The pumper carb(s) available will do the trick for sure, but i'm still struggleing with figuring out the root cause.
Does anyone one have a exploded view / detailed drawing of the CVK34 carb? I have searched the web but no luck. I would just like to see the details of the enrichment circuit and possibly get some feed back from a couple friends who are fuel system calibration experts.
Thanks
Don

 

Its -9 degrees C outside and I just tried the hand over the muffler trick without any luck (Choke + 5-6 cycles on e-start = nuthin')

I played with the choke and held it out, just before the detent spring takes over, and it fired up right away ... no sputtering, no almost starts ... it just started right away!

It was running steady at about 3K RPM and I let the choke go back to the normal position after 10-15 seconds, and it did the usual "not warmed up yet" idle, sputtered, then died.

Pulled the choke out full to engage the detent spring holder, and it wouldn't start. Pushed it back in and held it out like before and it started again right away!

Let it run for about 20-30 seconds and let the choke go, and it idled fine on its own. Still not fully warmed up yet, but kept idling smooth.

I held the choke out again and the idle incresed to 3K RPM. Pulling the choke out all the way, the idle increased to 3.5K RPM.

So, I don't know exactly what's going on with the choke mechanism, but it seems like the 3/4 choke position is definitly different than full on or full off. I'll try that as my first test case in my next cold start exercise.

I'd say it this technique was more impressive than the hand over exhaust approach. The only down side, if it works reliably, is that you have to manually hold the choke in the 3/4 position for half a minute or so. (Of course there's always the other down side -- riding your bike in -9 degree C weather!!! [:@])

 

YYY.GUY
I found that to work as well. I would slowly pull the choke out while cranking until it fired. I was able to get it on high idle till it warmed up. But I do agree having to cycle thru this choke position is a bit of a pain.

 

I was having trouble starting my bike today after a night in the teens. I read this thread and used the method of pulling out the choke slowly while starting and she fired right up!

 

It seems to me that the problem lies somewhere between gas starvation and inability to move the gas from liquid to vapor as the temps fall.

I'm guessing that the slow pull of the choke enables a better suction of the gas from the pilot jet since air is already flowing and a vacum is established before transferring the focus mostly to the pilot jet.

I don't know how that would positively effect the liquid to vapor need but perhaps thats being completed during compression....

Thoughts??

 

Sorry to bring this thread from the dead, but I hope to contribute what I found today with our bike and maybe others that are having cold start problemscan check on this to see if it is causing their problems as well. It would be good to get a concensus on this once and for all. Maybe, just maybe, this is it?

Since the daywe pickedour brand new 2006 KLX250S up at the dealership in July 2006, it has been hardto start from cold. The battery died while trying to crank it upin the parking lot before I could get it started to ride it home. Wehave been dealing with this every time we want to ride the thing. The dealer warrantied the battery thinking that was the problem, but it wasn't. After the battery did not fix it, they just said that it is a 250, and that 250's are cold natured.In winter, the only way to get it started is to hook it up to the car battery and let it turn the motor for a minute or so. It is just a bit of a pain. I have tried the heater method as someone mentioned earlier in this thread and it helps greatly. I have also tried letting the carb "pee" and that works sometimes too as long as it is warm outside. But, I just kept thinking there has to be something else wrong....

I pulled the carb today to take a look insidehoping to find the true cause of this problem thinking that a jet was clogged, or partially clogged. I found that the starter jet was clogged. I could not get carb cleaner to spray through it. I cleaned the jet and the bike started easily upon reassembly in freezing cold weather.

To help you locate this jet, it is thevery smallbrassjet that is non-removable and is pressed in right next to the main jet at the end of the stalk that extends to the bottom of the float bowl. The diameter of the hole in this jet is miniscule to say the least.

To clean it,I found a nylon bristle brush that had reallysmall diameter bristles and cut one bristle off of it with sharp scissors leaving the end of the bristle blunt and not smashed. I then pushed the blunttip of the bristle through the hole in the jet.Then, Iwas able to spray carb cleaner through the jet and passages behind it. With the enricher (choke) opened, carb cleaner was coming out of the enricherpassage on the engine side of the carb. With it closed, itseemed to becoming out of some other place in the carb, but I could not determine where exactly. I don't know for sure on this part, but you should probably remove the slide and diaphram from the carb before spraying carb cleaner though the enricher circuit in order to avoid damage to the diaphram from the solvent in the carb cleaner. I had mine out already.