KX Riders
Maintenance & Technical => KX250 / KX125 => Topic started by: bansheedave on May 20, 2015, 01:54:07 PM
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I am running v force 3 reeds in my 94 kx250. what I thought was a slipping clutch may be the reeds. I just want your opinions. what is going on is at high rpm, just before I need to shift into another gear or topping out in full top gear, the motor keeps pulling than all of a sudden it will just go high rev till either I shift or slow down for a split second and slowly roll on the gas again. the reeds show signs of wear on the tips but the aren't broken or splitting.
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https://www.youtube.com/watch?v=C0M_ZJfMnug
fast forward to 1:56 and you'll hear it
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Wow! Sounds like it is really leaning out on the top.
Reed pedals are cheap, replace them.
Then, with the airbox exposed, start it up and rev the motor.
Can you feel air blowing back through the filter?
If not that's good.
Make sure your throttle and kill switch are working properly :evil:
Take it for a ride and see what happens.
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I will get new reeds when I can. So do you think I could be ducking the bowl dry?
My jetting is 42 pilot, 170 main, needle set at 3rd from the top and also did a compression test and that's sitting at 235 psi
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Of course that's possible but I'm not really sure.
Before you do anything, do the hand over the air box thing and let us know.
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That definitely sounded like a Clutch to me...
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Yeah, I forgot to ask, when your in top gear like that and the engine does a quick wind up, is it trying to pull you faster as it normally does or is there very little acceleration?
If there is little acceleration, then DoldGuy has the right answer...
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if it's not the clutch, start looking for remnants of busted up snap rings in the bottom end/tranny.
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if it's not the clutch, start looking for remnants of busted up snap rings in the bottom end/tranny.
brand new bottom end and all new snap rings, bearings and a couple gears.
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Haven't started it yet today. Been to busy with other things so nothing to post today.
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if it's not the clutch, start looking for remnants of busted up snap rings in the bottom end/tranny.
brand new bottom end and all new snap rings, bearings and a couple gears.
that means nothing...they can break at any time.
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Dave,
After listening to it multiple times, the bike sounds like its unloading to a lower gear, which obviously would spike the RPMs. What gear were you in when this happened? I had a 95 KX250 & the Gear Dogs were rounded, shifted fine & would only do this when it had a big load on it as your video shows.
Next Ride, pay close attention to what gear you are in, and when it happens back off to mid throttle & shift to the next gear until run out of gears, to see if it actually is jumping down a gear.
DoldGuy
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After listening to it multiple times, the bike sounds like it unloading to a lower gear, which obviously would spike the RPMs.
that's what I believe it is...as I know that sound all too well and all too recent.
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It sounds transmission-y to me as well.
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the gear dogs did have wear on them when I rebuilt the motor and trans. the shift fork pins were also below minimum specs. I couldn't find new replacement forks because they are discontinued and buying a crap ton of shift forks to find good used ones in spec didn't seem to be cost effective. I am not sure when I'll be able to ride it again. I know in august will be my next chance. where would I find gears and forks if it is indeed the trans dropping out of gear? and if I have to tear it back down, I will be sending my spare 300 big bore out to get repaired.
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the gear dogs did have wear on them when I rebuilt the motor and trans. the shift fork pins were also below minimum specs. I couldn't find new replacement forks because they are discontinued and buying a crap ton of shift forks to find good used ones in spec didn't seem to be cost effective. I am not sure when I'll be able to ride it again. I know in august will be my next chance. where would I find gears and forks if it is indeed the trans dropping out of gear? and if I have to tear it back down, I will be sending my spare 300 big bore out to get repaired.
my 500 was doing exactly the same thing a little over a year ago...the main problem was a busted snap ring, a snap ring that was only 4 months old....I could run it hard through the gears, and once I clicked into 5th, within a couple seconds it would jump back into 4th...and scare the f**k outa me cause the rpm's went way too high.
Once I got it pulled apart, I also found the forks were worn, 2nd-3rd-4th-5th gears were all worn...the drum had some wear....there were a lot of things that contributed to it failing. So at that point, it made more sense to just replace the entire tranny and shift mechanism...as I had no interest mating new parts to old parts.
I know it may not be the best choice financially, but it might be easier to find a newer year motor where parts are more readily available...or...find a 500 motor and stuff it in there! :-)
Either way, keep us posted...and good luck.
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I have a 500 waiting in the wings for an eventual build.
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cool...what type of build?, an AF build or something different?...or is it still a secret?
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cool...what type of build?, an AF build or something different?...or is it still a secret?
it's an AF build. I have it currently sitting in a 99 honda cr125 frame.
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ahhhh...I think I remember reading/seeing something about that at one point.
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He's just teasing us with it at this point.
(http://i117.photobucket.com/albums/o43/bansheedave/11232281_10203896576756543_8893973044050235651_n2.jpg~original)
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I've seen it.
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Lol, what a nice looking picture. I have to report that the kx250 doesn't push air back threw the carb.