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About Thommo_400f

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  1. Thommo_400f

    Oil comming from crankcase vent tube

    Another possibility is that you might have a worn top end and exhaust gasses are pushing past the rings and pressurizing your crankcase...?
  2. Thommo_400f

    2009 Kx250f having idle problems

    Was it a valve replacement or just a shim job? Was the bike running weird before the valve job? The float height needs to be correct to make the rest of the jetting work properly. The kick symptom can be a few things. Crank bearing binding Kick starter gear missing tooth Valve clearance set wrong so auto-decompression stops working Timing set wrong.... but bike wouldn’t normally start in this case.
  3. Thommo_400f

    Clutch won’t disengage

    There is a steel ball which sits on the end of the pushrod. It may have fallen out if you disassembled the clutch basket? clutch won’t work without the ball.
  4. Thommo_400f

    kx250f won't start

    Fix intake clearance as it will be making it rich. Set fuel screw to 1 + 1/2 turns Check pilot jet size.
  5. Thommo_400f

    Kxf 250 starts but keeps cutting out

    Seems fuel related since it ran.. but cut out. Do you have good flow from tank to carb? Could also be low voltage from stator. Check resistance of stator and coil.
  6. Thommo_400f

    2009 kx250f misfiring

    If it is pushing oil out of breather it means the case is pressuring. That means gasses getting past rings. The miss firing is probably due to valves or air leak creating lean conditions. Sounds like full top end plus some general fixes.
  7. Thommo_400f

    2008 kx250f: Troubleshooting help needed!

    Just do the easy stuff first. Set the carb to stock pilot for your altitude and fuels screw at 1+1/2 turns. It should at least start and idle somewhere near those settings. If not, it’s likely there is something else causing your issue.
  8. Thommo_400f

    2008 kx250f: Troubleshooting help needed!

    A slightly miss-tuned pilot circuit will also make starting hard but the bike will run ok. The hot start could be leaking. The choke may not be seated. The pilot jet might be too small or blocked. Stator might have low resistance. Coil might have issues.
  9. Thommo_400f

    2008 kx250f: Troubleshooting help needed!

    The fact it runs fine after bump start means that your fuel mix must be pretty close to ok. I am guessing you may still have a valve or head issue. With slightly low compression you will never kick start it but a bump start increases compression just enough to start.
  10. Thommo_400f

    2008 kx250f: Troubleshooting help needed!

    Was this the reason for the new piston or has it happened after you installed the new piston?
  11. Thommo_400f

    KX250F 2007 - Bog, carburetor ?

    That popping you hear is a lean condition. Which means that your new parts have fixed some issues. You might need a bigger pilot now... or adjust needle richer.
  12. Thommo_400f

    KX250F 2007 - Bog, carburetor ?

    No ... not main jet. It’s called the “needle jet” or maybe “main nozzle” it is at the top of the tube above the main jet.
  13. Thommo_400f

    KX250F 2007 - Bog, carburetor ?

    I had a bike doing the same thing. Turned out to be a worn needle jet. The needle jet is the hole that the needle slides down into. Over years the needle rattles and rubs on the hole and makes it oval shaped. It makes the jetting slightly rich but is inconsistent due to needle moving in the hole.
  14. Thommo_400f

    Oil leak help

    That is a weep hole to tell you your water pump seal needs replacing. The seal keeps coolant from getting into your oil and vice versa. Cheap to fix if you are ok on the tools.
  15. Thommo_400f

    2009 kx250f weep hole issue

    Only tiny amounts of oil come out the hole, mixed with a bit of coolant so it looks worse than it really is. The main issue is that it means coolant is getting into your oil.