03 yz450f kick starter gets stuck

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:

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?

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

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:

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...

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...

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.

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 ?

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

ok i still don't see anything that looks bad

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?

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

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:

wow all the help here:blah:

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...

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:

...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.

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.

just a picture of what i'm working on:ride:010-3.jpg

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

  • Similar Content

    • By Samx22x
      Alright so I’m new to the site so maybe this question has already been asked. I have a 2002 Yz426f and I want a new exhaust, it has the stock header and silencer and sounds amazing but I’d like a little more from it, I know I want the fmf power bomb header and am kind of undecided on the silencer, I see on fmf’s website that their silencer will add low end and slightly take from top end and the other way around but I’m looking for increases throughout rpm range. I do a lot of trail, hill climbs, jumps, and wheelies so kind of need good performance everywhere in the rpms. My question is what silencer I should get and the jetting I should get for the carb. Thanks
    • By Zack Ailing
      hey guys just picked up a new project bike. Its a 2008 Yz450f with a big bore kit and a stroker crank. The total cc of the engine is now 499. It runs on race gas and will be an absolute monster when shes ready to rip. I will continue to make more videos on the bike so stay tuned Link to the video: 
    • By High On Octane
      2005 YZ450F, Athena Big Bore, Power Bomb, Q4.
      Ok.  Last fall after a decently hot day at the track, I noticed coolant leaking from the weep hole on my water pump after pulling into the pits.  Ordered an Athena re-seal kit, put it all back together and didn't really get a chance to ride it.  3 weeks ago, went out to the track, and after about 20 laps, it started leaking again.  Kept filling it with water to get thru the day, never ran anywhere close to dry or empty, jut a cup or 2 low.  Ordered a Hot Rods re-seal kit with bearing and also ordered a new w/p shaft.  Did it all again and got it back together, ran it, and as soon as it got to temp, it was leaking out of the weep hole again.
      So, what the heck am I missing?  I'm totally stumped on this one.  Is something wrong with my case cover?  Do I need to replace the w/p itself?  I'm feeling like I should've just ponied up for the Boysen in the first place, and now it's biting me in the butt.  Any help or suggestions is greatly appreciated.  Thanks!
    • By Awheeler25u
      Alright guys, my 04 YZ450f runs fine minus some slight backfires when decelerating (need to adjust fuel screw). The other day when I was done checking my valve clearances I changed the oil and filter and put the bike back on the stand, kicked it a few times without the ignition coil in to get some oil flowing got off and noticed a little drip spot on the ground, it was no bigger than a dime so I thought nothing of it. Started the bike with no issues took it for a quick 10-15 min ride, came back to the garage to find out my whole case was soaked with oil and it started pooling in the low spots on the clutch basket side. I cleaned all the oil off and took it out again for 5 mins to try and see where it was coming from, here are my three possible places but nothing directly leads me to believe it’s any of the three either.
      1. Decompression plug area
      2.  Valve cover gasket leak (not really sure because the amount of oil leaking Looks to be a large amount
      3. Oil tank (bad weld or cracked weld somewhere
      what are you guys thinking?
    • By bofar
      Hey guys. I could really use your help diagnosing an issue that came up riding today. Bike is a 2013 YZ450F. Well maintained and haven't had any issues until now. Both the oil and coolant are new and levels are to spec. 
      After riding for about an hour in the sand dunes, I noticed a grinding going on on the right side of the bottom end (from what I could tell). When I looked to see what was going on my kickstarter was vibrating and grinding really loud. This was a different sound than if you engaged the kickstarter while running. It sounded less "clanky" and more "vibrating/grinding" if that makes sense. Grabbing the kickstarter and moving it didn't help the issue.
      When I noticed it, I shut the bike off and gave it a second. Being a few miles deep into the dunes, I had to get it out of there so I started it back up and it seemed fine- no grinding. I headed back to the car and after a few minutes, it came back so I shut it off again, started it back up and nothing. That process happened one or two more times before I made it back to the truck. Seemed to run fine otherwise. 
      Once I got it back to the truck I started it up and tried to pay more attention to what was going on but it wasn't doing it. I did seem to have more of a metal on metal noise coming from the motor. I started and stopped the bike a few times and after the motor stopped there was a distinct metal clank/grinding noise that happened right after the motor shut of for maybe half a second. This doesn't happen every time. 
      I tried doing some research and have seen things that make me think it could be the spring that connects to the kickstarter, or the kickstarter stopper plate- but really I have no idea.
      Seems strange that the issue is off and on.
      Thanks for the help!