I have just got a 2001 Kawasaki mojave 250cc off of craigslist, the guy pulled it off the truck it cranked right up and ran fine, the next two times i started it and rode it it ran fine (all in the same hour) When i tried to crank it again i couldnt get it to kick start so i pull started it but if i didnt constantly give it gas it would turn off, I sprayed out the carb but did not take it apart and thoroughly clean it, i also took out the air filter and put the case back on, i can now get it to crank after kicking it mutiple times and it will idle okay but still wants to choke down if i dont slam on the gas, and sometimes i just cant get it to crank or idle right at all, when it is running it runs very good and strong, i've also noticed a little back firing when getting on the throttle real hard but i believe it is because of the type of exhaust on it, i also cleaned the spark plug as it was to late to get a new one and checked the fire and it was firing much better but still the same problem from time to time, the guy said it had sat for about 6 months I didnt drain the gas and just added 93 octane to it, im going to try and get it running right tommorrow any help tips or tricks would be much appreciated

 

Bad gas. Drain tank (and carb if you can.) Classic symptoms. Just adding hi-test doesn't cure the problem, it only dilutes it. Get a fresh plug if you can, too. Report back.
Glad to have you with us, bc.

 

I concur! lol as I sit here in my pilot suit

Welcome to KF

moved...

 

Ran it out of gas today took carb apart and cleaned it, it will only idle in neural and will only kickstart when the motors cold, and now its wanting to bog down sometimes now, still running stong though when it does, the only thing i can think of is valve adjustment or air/fuel ratio, my radiator fan is also not working, just checked that today, back to work on it tommorrow

 

The symptoms sound like more carburetor cleaning / checking needed. In particular, the main jet. Starts and idles, trouble when you move off of idle jet onto main.



Image originally posted by Redondo Ron on a now defunct AOL website in 1998. The pictures and text are all his. Many thanks.

Did you get that Pilot Jet down there in the tower? Also, the bogging may be related to the diaphragm not properly seated, or a hole / tear where there wasn't one before. A damaged diaphragm will have the symptoms of the engine being able to idle, but will not accept any throttle. Might account for your bogging. As far as your air / fuel mix, the idle mixture adjusting screw turned two full turns out from stop is a good starting place.

Be patient. I've had to go into the same carburetor three or four times and re-clean what I thought was a spotless carburetor and jets. Sometimes, its a matter of using different cleaning solvents, sometimes it's just the way I hold my tongue when I put it all back together. The point is, with some patience and a few chemical tricks, you can get it. This is you, with your supreme intellect and apposing thumbs against simple corrosion. My money's on you Buddy.

 

thanks for the diagram fuller, ill try a good cleaning again someone told me to boil it for about 15 minutes not sure if this is a good idea, i couldnt even give it half throttle today someone had put an aluminum street bike muffler on there and tried to weld it with steel mig wire after a few jumps it eventually broke off and i got my power back, but still it wants to turn off when not giving gas and i still cannot kick start it when the motor is hot can only kick start it when its cold, what could this be? and if anyone could tell me what weight or type oil to put in it would be much appreciated as i did not get a manual with it

 

I was also told to cut the gas filter off and run just a pipe but i did this with a dirt bike once and had problems in the future with it

 

We each have our own ways of doing things. I like to do one thing at a time when trouble shooting. I would, at this point, focus on removing and cleaning the jets and making sure the diaphragm is seated and not damaged. Aerosol carburetor cleaners are useful in forcing / flushing crap out and insuring that there is no restrictions. Most of them won't dissolve the plaque and varnish. I like to use a fuel injection cleaner like Chevron 65740 Techron Concentrate Plus Fuel System Cleaner [NOT Pro-Gard] or Gumout Regane fuel system cleaner and soak the jets in it. If the carburetors are caked with crap inside and out I boil them, otherwise, I get by with focusing on jets and passages.

Your project is turning into quite the can of worms. You gotta have a muffler on the exhaust side of things to provide some back pressure. I have no idea if this welded on muffler provided more or less back pressure than the stock muffler. In order to create a balance that allows the carburetor to feed a balanced amount of fuel and air to the engine the intake air flow must match the exhaust back pressure. When you alter either end or both [intake air / exhaust] you typically have to re-jet the carburetor to compensate. See if you can find some numbers on the jets when you take them out to clean them. Someone may have already replaced / tinkered with the stock ones. This can become a can of worms.

The hard start when warm is a symptom of too tight of a valve setting. That particular engine is very sensitive to it's valve setting, and tight valves are the leading cause of death, followed by cam wear from not changing the oil often enough.

This video applies to both the KLR250 and the Mojave valve adjustment.

 

thanks for the advice and the vid fuller ill see what i can come up with