Jump to content

2014 KX250F questions

Recommended Posts

I have a 2014 KX250F purchased used and pulled the motor for our Outlaw kart. My son runs it nearly WOT on 1/8th mile clay oval. Engine turns 13600 most of the time. I did a valve inspection and the intakes were tight along with exhaust. i shimmed exhaust and they worked out. The intakes took several tries and tightened up again. I also replaced stock cams with stage 1 hot cams and FMF Mega-bomb pipe stock muffler. We noticed no change in the performance. Race season is over so the engine is opened up. The head looks to have had a little dremel work done at base of the intake seats and back edge of the exhaust ports. I am not sure if the valves are Ti or SS. It had dual valve springs in it. I have read lots of posts about big bore, high compression piston, fully built head etc. I am looking for some answers as to SS valves using the dual springs I already have. What seats for the SS valves and what guides I should use. We run against JGR 250's. I don't plan to spend multiple thousands of dollars.  Our piston appears to have worn on the sides and the light scratches on the cylinder. Not sure if I can hone it and reuse it.  We run race fuel currently. plugs look dry and light tan. pipe is powder white inside front to back.  I'm looking for some insights from those that have experience with tuning and mods for mostly WOT use. We don't shift the kart is push started runs in 4 gear. 

Things We are contemplating:

We use stock clutch now and pull wheelies out of the turns . any use for a high dollar clutch? 

REM polishing all internal parts?

balancing stock crank and rod?

269 kit or HC piston?

Stage 2 Hot Cams?

porting and polishing the head.

Kawasaki laptop tuning?



cylender 2 (2).jpg

cylender 3 (2).jpg


22R Wheelie.jpg

Edited by protex1
  • Like 1

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

Reply with:

  • Similar Content

    • By Toms.abpg
      Just bought this bike and the pop on decel is horrible, looks like I’m gunna have to try a Tokyo mods remap. Anyone had success with this ?
    • By _Cloudy_
      Hi, I have just bought a kx250f, 2013 with a freshly rebuilt 2016 motor in it, this is my first time on these forums, anyways, I have also bought a lowering link to drop it 4 inches on the arse, I was wondering if anyone knows how much I should drop the forks? 
      I havent put the lowering link on yet. 
    • By Zach Miner
      Recently had issues with the original fcr carburator that was installed in my 2009 kx250f, tried jetting multiple time and different gas and the bike would only run with the choke ziptied out. Do I went ahead and purchased the lectron gen 2 4 stroke carburator kit, was kinda expensive and I was kind sceptical but after my first ride all I got to say is wow. The only adjustment I have done it set the idle, the bike runs amazing and feels as if there is more power than before. The kit came with a new throttle tube assembly and a g2 throttle tube with adjustable cams for throttle response. I highly recommend if you have a carburator on your four stroke and don't want to get a new dirtbike that is fuel injection then go the route of throwing out that junk fcr carburator and get a lectron gen 2 carburator for your old 4 stroke

    • By DirtbikeDon
      I own a 2012 Kx250F that I would like to make street legal if possible and I recently saw Rocky mountain I believe sells these battery packs that sit in the airbox for bikes without batteries that looks too good to be true and a headlight and turn signals like a conversion kit basically and I was curious as if anyone has had luck with those or if there junk it would be nice to make my bike street legal for short trips or just have lights for trail riding with friends that already do if possible any tips on converting it? 
    • By kylesmith_14
      The launch control only lights up when you first start up the bike when you try to use the launch control it doesnt light up at all ive tried 1st 2nd and neutral for 3+ seconds ive cleaned the connections and also cleaned the neutral saftey switch or gear selector and still no luck any help would be appreciated