Hey guys, I have a 2010 kx250f I am having trouble with keeping it running. Any ideas on what it possibly could be?
*** A little history on the bike. I got the bike from a friend. He was out riding one day and the bike would continuously shut off unless you were in the throttle. He let it sit for a year and a half never touched it. He was told by a guy at the track the bike may need a valve adjustment.. and he never touched it from there. When I got the bike from him I was looking into it and notice the fuel mixture screw was missing. I got one and thought that may be my problem.. well here I am now..***
-I can only get the bike to run with the choke on and when I turn the idle screw down it idles perfect but as soon as I turn the idle screw back up to normal sounding with the choke on, the bike will idle for a few seconds and die out. Also I did notice the squirt from the accelerator pump is really weak. I have tried adjusting the screw to find the “sweet spot” still can seem to find it. I’ve tried the o-ring mod as well on the needle and still can’t figure it out.
While taking the cylinder head off I noticed a hair line score. Not any noticeable compression loss though. (I plan to rebuild that once I can figure this other issue out)
(I do not know when the previous owners rebuilt the bike!! I know it has been rebuilt or messed with because there was gasket maker between the valve cover gasket and the head.)
-I have noticed the cam chain seems to be stretched out and loose a little bit but I don’t think with it being stretched out would cause this problem. I may be wrong on that I’m not exactly sure, correct me if I’m wrong please.
-I’ve already rebuilt and clean the carb several times, upped the pilot jet (42 and 45 from 40) and went down in the leak jet as well (45 and 50), (55 was already in it when I got the bike)
-I’ve did a valve adjustment on it and triple checked everything and one of the exhaust valves is out of spec already.
Any help would and is GREATLY appreciated, Thanks!
-Mike
*** A little history on the bike. I got the bike from a friend. He was out riding one day and the bike would continuously shut off unless you were in the throttle. He let it sit for a year and a half never touched it. He was told by a guy at the track the bike may need a valve adjustment.. and he never touched it from there. When I got the bike from him I was looking into it and notice the fuel mixture screw was missing. I got one and thought that may be my problem.. well here I am now..***
-I can only get the bike to run with the choke on and when I turn the idle screw down it idles perfect but as soon as I turn the idle screw back up to normal sounding with the choke on, the bike will idle for a few seconds and die out. Also I did notice the squirt from the accelerator pump is really weak. I have tried adjusting the screw to find the “sweet spot” still can seem to find it. I’ve tried the o-ring mod as well on the needle and still can’t figure it out.
While taking the cylinder head off I noticed a hair line score. Not any noticeable compression loss though. (I plan to rebuild that once I can figure this other issue out)
(I do not know when the previous owners rebuilt the bike!! I know it has been rebuilt or messed with because there was gasket maker between the valve cover gasket and the head.)
-I have noticed the cam chain seems to be stretched out and loose a little bit but I don’t think with it being stretched out would cause this problem. I may be wrong on that I’m not exactly sure, correct me if I’m wrong please.
-I’ve already rebuilt and clean the carb several times, upped the pilot jet (42 and 45 from 40) and went down in the leak jet as well (45 and 50), (55 was already in it when I got the bike)
-I’ve did a valve adjustment on it and triple checked everything and one of the exhaust valves is out of spec already.
Any help would and is GREATLY appreciated, Thanks!
-Mike