03 yz450f kick starter gets stuck

24 replies to this topic
  • 66c10

Posted May 15, 2011 - 05:41 AM


i have searched this out & have really not found the answer to this problem...i just picked this bike up because the old owner was having problems & was riding when the rear wheel locked up after a small jump & he tryed restarting & the kick start was locked up...he has taken it apart a bunch of times & just could not find the problem...he got tired of messing with it & now i have it:banana: now i have taken it apart & pulled the kick start assembly out & have studied it & just don't see what is going on inside...the motor turns free...i have read up here to use a assembly out of a 05 bike & have gone to the parts store here at TT & checked out the part numbers from the 05 & the 03 & the only difference i can see is the spring guide & the spring they have different parts numbers all others parts have the same numbers...the assembly numbers are different but with only these 2 parts being different...i can roll it back & forth & it frees the kicker up some...i want to ride this beast but don't want the rear wheel locking up on me........i need some help here & thanks:ride:

  • 66c10

Posted May 15, 2011 - 07:26 AM


well i spoke to soon :thumbsup:
i have gone further into it & with the clutch basket off i thought i could turn it over complete but that is not the case...it goes through compression & then stops i can turn it backwards & same thing i feel & hear compression & then it stops solid...i took the counter weight gear off & same thing ,i pulled the left side case & all is well,i pulled the cam cover off & cannot see anything wrong in there...i can look thru the right side & see the crank moving & the bottom of the piston...what could it be if i have compression?

  • Aka.Goose

Posted May 15, 2011 - 08:57 AM


Timings off (skipped from stretched cam chain), or bad crank bearings, would be my two guesses...

  • 66c10

Posted May 15, 2011 - 11:44 AM


ok, here is what happened......up on the valve cover there is a piece to the chain tensioner that has 2 tits on it that fell to the bottom inbetween the chain & lower gear,had to pull the whole top end to get it out & now she turns free all the way around:thumbsup: now why would this fall out? what holds it up in place? i am new to these hi tech 4 strokes & learning on the way:ride:

  • Aka.Goose

Posted May 15, 2011 - 12:08 PM


lol...I don't know anything about tits on the tensioner, but I have heard of the plastic guide on the cam cover breaking loose...(#12 in the parts diagram)

  • 66c10

Posted May 15, 2011 - 12:18 PM


yep thats it...the cover has 2 nubs or "tits" that this guide fits on...what holds the guide in place? does it snap on? if so this one just falls off...

  • Aka.Goose

Posted May 15, 2011 - 12:32 PM


I believe it does just snap in place...I vaguely remember a thread about it years ago...I think the guy ended up using some epoxy to hold it in place...The thing is, if the chain knocked it free, most likely your cam chain is stretched and/or has a kink in it, and should be replaced along with the guide...
I'm sure grayracer will chime in here soon, and give you better info than I can...

  • grayracer513

Posted May 16, 2011 - 08:18 AM


The upper guide snaps in place. Replace it and you should be OK.

The '03 kick starter as originally issued was superseded, and can't be bought from Yamaha. The original part number is still listed by Yamaha (5TA-15601-00-00), but usually, when a counterman looks that up, his "book" changes up to 5XD-15601-00-00 automatically. Depends on where you look.

  • 66c10

Posted June 18, 2011 - 07:24 PM


ok i am back to where i started...it has been put all back together now for a few weeks now & i have not had any problems then today i went for a little ride & went to turn around & it stalled,it cranked right back up & i took off again & when i slowed down it stalled again & when i went to crank it the kickstart was locked up...i put it in second gear & rolled her back & forth a little & it unlocked so i tryed to start & it feels like it wants to lock up again so i pushed her home:banghead: what do i need to look for ?

  • 66c10

Posted June 19, 2011 - 06:17 AM


i have it tore down this morning while it was locked up...all looks good & tryed pushing on kick starter & would not move, took the clutch basket off & motor turns free...:ride: i don't see anything wrong

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  • 66c10

Posted June 21, 2011 - 03:30 PM


ok i still don't see anything that looks bad

  • 66c10

Posted June 24, 2011 - 06:47 PM


i messed with it somemore tonight & found i can turn the motor over easy using the nut on the flywheel with the plug out & clutch basket out,when i put the basket in it will not kick over with the kicker but i can turn it with the flywheel nut...when i grab the basket it will not move so i took the oil pump gear off & the same thing happens so i took the kicker idler gear out & same thing cannot turn the basket but i can still turn the flywheel & the motor turns fine...so looking at the basket the gear on it has some movement like it is coming loose...the manual says trash it if any movement.......could this be my problem?is there enough play in the gear when it trys to turn it is meshing into the crank gear to deep & causing binding? anyone seen this happen?

  • 66c10

Posted July 02, 2011 - 02:01 PM


still no fix.......maybe it's a parts bike

  • 66c10

Posted July 02, 2011 - 05:02 PM


i put it in 4th gear & rolled her back & forth & the motor was turning over easy, tryed to start & it started like it should & let it idle & it died...tryed to start & it felt like the kicker was binding,put in 4th gear again & it loosened up & started fine & stalled again......same ole thing kicker felt like it was binding up:bonk: so i parked her to the back & will play with the good ole red bikes for awhile:thumbsup: anyone ? need some help here...this bike is awesome when running right but it has this flaw that i can't seem to get figured out & thought since this is thumper talk i would get some ideas:worthy::thumbsup:

  • 66c10

Posted July 06, 2011 - 06:50 PM


wow all the help here:blah:

  • Aka.Goose

Posted July 07, 2011 - 08:04 AM


I'm still going with "your bottom end bearings are shot" (my guess from 2 months ago)...
They'll fool you like that sometimes, be locked up on one kick, then free the next...
Sometimes you can start it, but then the crank bearings bind up and it dies...

  • 66c10

Posted July 07, 2011 - 01:18 PM


when i had the top end off i checked the crank & there was no up & down play & very little side to side play...the guy i got it from said he had new bearings installed on the crank when he redone the head...i found a 05 kick starter assembly on ebay that i am waiting on now to see what it does & if it don't help i guess i split the cases...is there a way i can check the bottom rod bearing before pulling the engine...with the clutch basket removed the crank turns fine, no binding at all...thanks for the response Goose:thumbsup: when the bike was running after i put it all back together it was a beast & very powerful & i thought i had her fixed ,,,can't wait to ride it again:ride:

  • grayracer513

Posted July 07, 2011 - 02:06 PM


...is there a way i can check the bottom rod bearing before pulling the engine...

Page 2-7 of the manual. Have to have the head and piston off, though.

At the moment when your starter hangs up, without bumping it back and forth in gear or anything, can you turn the engine forward by using a 17mm socket on the end of the crank (counterclockwise from that perspective)? If so, the problem is the starter assembly or the starter gear train, not the engine or trans.

  • 66c10

Posted July 07, 2011 - 02:48 PM


yes when it hangs up & the kicker is binding i can turn the motor freely with the 17mm socket on the left side of the crank...i can take the clutch basket out & it still turns free at the crank nut, the motor is never binding only when i try to use the kickstarter...i have looked everything over & all looks good...whatever they changed on the kickstarter assembly had to be a bad flaw in design if they changed it that quick & i'm hoping this will fix my problem...if you do a search here for 03 yz450f kickstarter it looks like this was a big problem for this year bike...i hope the new used part gets here by the weekend for me to try out & i will compare the 2 parts & see the difference...thanks for the help:thumbsup:

Page 2-7 of the manual. Have to have the head and piston off, though.

At the moment when your starter hangs up, without bumping it back and forth in gear or anything, can you turn the engine forward by using a 17mm socket on the end of the crank (counterclockwise from that perspective)? If so, the problem is the starter assembly or the starter gear train, not the engine or trans.

  • 66c10

Posted July 07, 2011 - 03:36 PM


just a picture of what i'm working on:ride:Posted Image

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