04 250f no start
  • Aussiecrf230
    Posts: 1962
    Joined: Fri Jan 06, 2006 11:11 pm

    Re: 04 250f no start

    by Aussiecrf230 » Tue Oct 16, 2018 3:30 pm

    Hi pmachan,
    Feel your pain with this bike.
    When you say it is not starting is it backfiring at all or just no signs of trying to start.
    Have you tried a bit of ether/starting fluid (we have "start ya bas t ard" brand here in oz). I have found with hard to start engines this can make a real difference as I can't really kick over as hard as when I was younger.
    To run an engine needs fuel/air, spark and compression. Even if slightly off the engine should still give a pop out one end or the other.
    Ray
    Australia

    CRF230F 2004
    C30F Power Up needle
    Mains 132
    Idle 45
    2 turns out
    Baffle out, Screens In

    It starts,it runs,it gets to where all CRFs can get to without the valve or valve plate dramas
  • pmachan
    Posts: 15
    Joined: Thu Oct 11, 2018 6:25 pm

    Re: 04 250f no start

    by pmachan » Tue Oct 16, 2018 4:44 pm

    Hi pmachan,
    Feel your pain with this bike.
    When you say it is not starting is it backfiring at all or just no signs of trying to start.
    Have you tried a bit of ether/starting fluid (we have "start ya bas t ard" brand here in oz). I have found with hard to start engines this can make a real difference as I can't really kick over as hard as when I was younger.
    To run an engine needs fuel/air, spark and compression. Even if slightly off the engine should still give a pop out one end or the other.
    Yeah, it will backfire occasionally, and kick back through the kickstarter. I have tried starting fluid, with no luck.

    Jimdirt, forgot to mention flywheel in last post, it has a new steahly flywheel, I removed it and replaced with stock on just in case, woodroof key and slots were all fine.
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    JimDirt
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    Re: 04 250f no start

    by JimDirt » Tue Oct 16, 2018 5:34 pm

    Tank was drained, carb fully rebuilt with new everything last week.
    It has fresh race gas.

    Well , i guess that was not it then , I was hoping it was something simple like that , the fact that it backfires and kicks back at the kicker , seems to me that its either still starving for fuel , or its a ignition issue of some kind (not sure what because you replaced everything related , which is baffling) , going to sound like a broken record , but , give it about 10 full twists of the throttle and full choke and kick it like you stubbed your toe on it , 4 hard kicks making sure you are on the compression stroke ..... if it does the exact same after that , then I am leaning towards some kind of ignition or timing fault , as this makes no sense

    Also , try disconnecting the kill switch , just in case its grounded out , sometimes they go bad and ground out even without pushing the plunger down , there should be a 2 wire independant plug set , right down by the frame spar and the triple clamp

    If that does nothing , then i am stumped , maybe someone else can come up with something here , but you have basically covered everything logical that comes to mind , or that I have run across... that I can recall at least ..... 8-[ :-k
    2020 CRF450R
    2006 CRF450X
    Image
    Weiser , Idaho
  • Aussiecrf230
    Posts: 1962
    Joined: Fri Jan 06, 2006 11:11 pm

    Re: 04 250f no start

    by Aussiecrf230 » Tue Oct 16, 2018 9:13 pm

    I bet in the end it will be something simple still.
    Me thinks it is time for a compression test just to take it off the list of possible causes. You said tons of compression, is there an actual psi from a gauge?

    The next thing I would check is that everything that suppose to be earthed is and there is a path between them all, so that all the earth points are at same potential. The bike has had a lot of work by the previous owner so in their haste to get it back together an issue may have been created.

    When you kick the bike over with the plug out is it consistent multiple sparks or does it miss one sometimes.

    If it is kicking back at the kickstarter you would have to think it maybe firing well before top dead centre. Perhaps check the trigger behind the flywheel as may have been damaged.

    Hope this helps mate.
    Ray
    Australia

    CRF230F 2004
    C30F Power Up needle
    Mains 132
    Idle 45
    2 turns out
    Baffle out, Screens In

    It starts,it runs,it gets to where all CRFs can get to without the valve or valve plate dramas
  • pmachan
    Posts: 15
    Joined: Thu Oct 11, 2018 6:25 pm

    Re: 04 250f no start

    by pmachan » Wed Oct 17, 2018 5:03 pm

    Really starting to get frustrated with this thing.
    Did the clutch mod so I can bump start it, but it has so much compression it will just drag the back wheel as soon as it hits the comp stroke, even in 5th gear.

    Just at a loss, every single part has been verified, replaced, tested, there is simply nothing left.
    Every wire, ground, kill switch, entire engine, just maddening.
  • pmachan
    Posts: 15
    Joined: Thu Oct 11, 2018 6:25 pm

    Re: 04 250f no start

    by pmachan » Wed Oct 17, 2018 5:28 pm

    So more details on the alignment of the flywheel, the punch mark on the right side (the mark Honda uses in the manual) and the cam, in relation to TDC.

    On my engine, the flywheel is more accurate to true TDC, when I check with a dowel, the piston is at TDC when the 1st little mark on the flywheel, is lined up with the case notch, in this alignment, the cam gear marks are perfectly flush with the head.
    However, in this alignment, the punch mark on the right side gear is NOT lined up with the case mark.
    I will say though, its not *that* far off, and the valve clearances are the same with either/or each side lined up. It should still bloody well start.

    I have pics of all this but they are not easy to upload from a phone, pics are too big.

    I am hoping this thread will be useful to someone once I get it figured out because there are many others with similar posts (same issue), that go nowhere.
  • pmachan
    Posts: 15
    Joined: Thu Oct 11, 2018 6:25 pm

    Re: 04 250f no start

    by pmachan » Thu Oct 18, 2018 7:49 am

    Update, I got it to run, bump start. Last night was wet, so was difficult to get traction, today was dry and it worked.

    Runs fine, idles, drives around fine, snappy throttle.
    So I know it works, now I can fine tune, I'll buy a shim kit and shim valves to exactly factory specs, intakes are currently a bit loose and ex a bit tight. I have a hard time seeing how this would affect cold starts, as there is plenty of clearance cold, but a lot about this motor doesn't make sense, so who knows.

    BTW, I stuck with the cam being aligned to the flywheel as opposed to the right side gear, I am temped to try it the other way and see if it runs differently, its a 1 tooth change on the cam.
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    JimDirt
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    Re: 04 250f no start

    by JimDirt » Thu Oct 18, 2018 12:59 pm

    Since bump starting , will it now start "normally" ??
    2020 CRF450R
    2006 CRF450X
    Image
    Weiser , Idaho
  • pmachan
    Posts: 15
    Joined: Thu Oct 11, 2018 6:25 pm

    Re: 04 250f no start

    by pmachan » Fri Oct 19, 2018 8:43 am

    Since bump starting , will it now start "normally" ??
    Not a chance.
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    JimDirt
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    Re: 04 250f no start

    by JimDirt » Fri Oct 19, 2018 7:35 pm

    Well that sucks , I am still confused about the timing marks being off , .... Another question , excluding the cam gear , can you get both the flywheel and the balancer gear to be on their marks at the same time without worrying about the cam gear ?? , like set the balancer gear , then look to see if the flywheel is on , then aligning the cam to that ?? , maybe pull the balancer gear and see if it will move 1 tooth , something is not right with this , and i think its the contributing factor for the starting , it runs , so its not off far enough for that , so maybe its just making it difficult by being off that much 8-[
    2020 CRF450R
    2006 CRF450X
    Image
    Weiser , Idaho
  • pmachan
    Posts: 15
    Joined: Thu Oct 11, 2018 6:25 pm

    Re: 04 250f no start

    by pmachan » Sat Oct 20, 2018 8:16 am

    Well that sucks , I am still confused about the timing marks being off , .... Another question , excluding the cam gear , can you get both the flywheel and the balancer gear to be on their marks at the same time without worrying about the cam gear ?? , like set the balancer gear , then look to see if the flywheel is on , then aligning the cam to that ?? , maybe pull the balancer gear and see if it will move 1 tooth , something is not right with this , and i think its the contributing factor for the starting , it runs , so its not off far enough for that , so maybe its just making it difficult by being off that much 8-[
    No, the balancer gear and flywheel won't ever be lined up together. However, the balancer gear doesn't really matter, the flywheel is keyed to the crank, and when it lines up, its at true TDC, I verified with a dowel in the plug hole.
    If the balancer gear if off a tooth it doesn't affect anything, exept confusing results when trying to find TDC.
    After a LOT of research, I am definetly not the only person to have this issue.
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    JimDirt
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    Re: 04 250f no start

    by JimDirt » Sat Oct 20, 2018 8:39 am

    I understand the balancer does not affect timing , but what i am getting at is with it being off , i am wondering if maybe the chain gear behind the flywheel is the issue throwing the timing off , basically , there has to be a reason behind it not aligning , that is my main point , in other words , the timing being off 1 tooth will affect starting , not so much running until you get to higher RPM's where the valves may touch the piston , but the issue you are having is with starting , so having the cam off enough that the valve opening is off time may be enough to hasten starting at the slower RPM's the engine is turning while kick starting rather than when you bump start it which has more momentum

    Usually , aside from timing being off , the only reason a bike would not start kicking , but with bump starting is the ignition system having a bad component , like a weak coil or stator , allowing you spark in open air when checking the plug , but under compression , the spark is not enough to actually fire the bike

    I am wondering if the CKP Sensor is going bad (inside the ignition cover which picks up the pulse from the stator) , a weak one would allow the bike to run , but make it difficult to start

    Just throwing things out there , as any one of these factors can lead to hard starting , since you confirmed it will actually start and run , once its actually started (only by bump starting it seems), then the issue is something not aligned in the timing , or , a weak electrical output during the starting procedure , maybe recheck Stator output , etc , and see if you missed something :-k
    2020 CRF450R
    2006 CRF450X
    Image
    Weiser , Idaho
  • Boman09
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    Joined: Sat Sep 22, 2018 7:37 am

    Re: 04 250f no start

    by Boman09 » Sat Oct 20, 2018 8:41 am

    The Timing marks do not all line up, the 07 i just picked up was same way popping and no start i check timing and when the marks are line up on clutch side bike would not start so i set cam timing to match timing marks and she fires within 2 kicks cold bike runs great and starts great hot or cold.
  • pmachan
    Posts: 15
    Joined: Thu Oct 11, 2018 6:25 pm

    Re: 04 250f no start

    by pmachan » Tue Oct 23, 2018 6:57 am

    The Timing marks do not all line up, the 07 i just picked up was same way popping and no start i check timing and when the marks are line up on clutch side bike would not start so i set cam timing to match timing marks and she fires within 2 kicks cold bike runs great and starts great hot or cold.
    I did the same thing, but still having trouble.
    I am now thinking the modded decomp weight is affecting things.
    The bike has a HC piston, 13.5:1, along with a stage 2 cam, and the decomp mod performed (reduced decompression), and the bike is really hard to kick over, and also tricky to bump start even, it just locks up most of the time.
    So now installing a stock decomp weight and spring to see if I can get the motor spinning a bit faster during kickover.
  • pmachan
    Posts: 15
    Joined: Thu Oct 11, 2018 6:25 pm

    Re: 04 250f no start

    by pmachan » Tue Oct 30, 2018 9:24 am

    So this seems to be fixed.
    Installed a stock decomp mechanism, it had the modified lever installed.
    Seems with the HC piston, larger cam, and cold-ish temps, the bike could not be kicked over with enough speed to fire.
    Stock decomp installed, and its MUCH easier to kick over and will start, its not easy, but it will start.
    Oddly, it won't start cold with the choke.

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