Jump to content
Sign in to follow this  

help needed

Recommended Posts

firt of all hi all hoping on some help

owned a kxf 250 07 for about 3 months a very clean looked after bike

the bike has never idle propley but run fine the bloke tells me he changed the pipe

just recent the bike started back firing when leting off the throttle or slowing down i got a whole top end rebuild and clean carb the bike still does it

when on idle the bike is running to slow so i turned up idel to make it run and it runs but with a poping and when i rev up i get back firing and sometime flames as soon as i put the choke on the bike runs to fast so i turn the idle down the bike runs fine no poping or back firing i have orderd a 42 jet and a deep bowl for carb any other idea please

Share this post


Link to post
Share on other sites

Sounds like you are on the right track. The 42 pilot will help plus your should check for air leaks and make sure your hot start is seating properly and not sticking.

Share this post


Link to post
Share on other sites

Sounds like a clogged pilot jet.. How ever.. an air leak [stuck hot start or from an airboot]

there also could be a crack in the header somewhere..Valve clearances can cause this but most of the time it just causes hard starting to begin with I would check the pilot first as that sounds like it problem the cause..

Share this post


Link to post
Share on other sites

an airboot will be the rubber connection from the airbox to the carb and the rubber passage that connects the carb to the head of the engine..

Share this post


Link to post
Share on other sites

i recently done the hotstart plunger as i was getting popping on deceleration ,ive now fitted an aftermarket exhaust system (arrow) and when i start it and rev flames are shhoting out ,my next thing is to change the pilot to a 42 ,would this solve it ? or could it be burnt fuel ,i have not rode it yet just to add.the bikes a 08 kxf 250, leadbeatter where you from in england ,im from newcastle

Share this post


Link to post
Share on other sites

hi huys and gals ples73 im from kent

i have today done the jet and cleaned the carb for the 4th time still have the exact problem,its running fine on choke soon as i take it of choke it wont idle and as soon as i pull the throttle back it wants to die if i give it a little rev and then another it will rev right up but does backfire and sounds ruff HELP ME IM ABOUT TO CRUSH IT WITH MY BEAR HANDS

Share this post


Link to post
Share on other sites

did you try a new needle? your carb needle may be worn and causing your idle problem. Or it is just the incorrect needle for your setup. The size of the needle nearest the clip, before it starts to taper, is where the idle could be affected. Granted, your pilot controls the idle for the most part, but that is assuming your needle is sized correctly at the initial (largest) diameter.

Second, you may have a leak where the headpipe mates to the midpipe. If that leaks air, you will get popping on decel and could get some idle problems too.

I have changed needles a bunch and I have seen firsthand how those can affect the starting and the idle of your bike, without touching the pilot or fuel screw.

Share this post


Link to post
Share on other sites

Ok, let me ask.. does your carb still have the fuel screw in it? have you tried adjusting it???

Next if you have and it still is an issue then your valve timing is most likly off.. either a strechted cam chain that jumped timing or your cam sprocket moved..

Share this post


Link to post
Share on other sites

its been like 3 days and you failed to mention if you checked half of the things they told you to do? doesnt seem to make sense

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Sign in to follow this  

×