05 CRF450x Missing Valve Parts On Running Motor? Newbie Questions.
  • familyguyfan84
    Posts: 3
    Joined: Sat Jul 04, 2020 12:34 pm

    05 CRF450x Missing Valve Parts On Running Motor? Newbie Questions.

    by familyguyfan84 » Sat Jul 04, 2020 12:56 pm

    Hey everyone.

    I'm new to the forums, and very new to bike maintenance, so please bare with me. This is going to sound really stupid, so hold on to your hats. The important stuff is at the end. Thank you all in advance for your help!

    I recently bought an 05 CRF450x from a friend of mine, after he "blew the motor". After disassembly of the top end, it turns out that he just lost a keeper on one of the intake valves, and bent the valve a little bit. Ordered new valves, seals, guides, and everything to rebuild the head. Put everything back together, checked clearances, and started it up. Upon start up, the bike was ticking loudly. I sent a video to some friends, and we agreed it was a valve adjustment or cam chain issue.

    I started looking at parts diagrams, and came across a picture that has cups on the intake valve springs, but not on the exhaust.
    When I disassembled the heads, there were NO CUPS/BUCKETS at all on it. I'm 100% certain of this. I've torn my garage apart trying to find them, just incase I was losing my mind. The bike ran great before I got it, and never made these sounds.

    My questions is two part:
    1- Are there only shim cups on the intake side of this motor, and nothing on the exhaust?
    2- How in the hell was this bike running just fine, before I got it, and now sounds like a bucket of bolts?
  • User avatar
    JimDirt
    Posts: 4406
    Joined: Sat Nov 25, 2006 6:31 pm

    Re: 05 CRF450x Missing Valve Parts On Running Motor? Newbie Questions.

    by JimDirt » Sat Jul 04, 2020 1:56 pm

    Welcome to the site !! \:D/

    To question 1 ..... Correct , only shims on the Intake side , as the Exhaust runs off the rockers where the Intake run directly off the cam ....

    #2 ..... My only explanation is before you picked it up , he did a valve lash check and maybe tried to adjust them , which means the tower has to come off , if he set it down and the buckets were still in it , then slid out on the bench , then he inadvertently put the tower back on without checking to see if the buckets were intact , then that would be why before when you heard it run , it was fine , then before you picked it up ,I am betting he forgot to put the buckets on after a adjustment , and THAT is what knocked the keeper off and that is why the valve dinked .... my other concern is that the valve hit the piston , in which case I would be heavily concerned about a lower rod bearing being kaput , it does not take much force to do this , and a valve hitting a piston is plenty enough force to take out the bearing , either right away , or soon down the road , and may be part of the racket you are hearing , , which would mean , new crank , I am surprised the shims were still there in the valve spring pocket , usually because of the oil they stick to the bucket ...... or you did the same thing :-k , and somewhere in your shop/garage is 2 buckets ....... anyway , DO NOT run the engine even 1 second longer without the buckets in place :shock:

    As for why the engine ran fine before , I would say because the buckets were in place ... 8-[

    Also , now that you have new valves (hopefully you had the seats cut , and did not lap the valves) , most likely the shims that were/are in there are no longer within spec as a worn valve (any wear) will change the shim size , so you will have to reshim anyway , because the stem to seat length has changed , but again , do not fire the engine without buckets in place ...period .....

    My last suggestion is if you plan on keeping this bike ..spend the $60 and get a Factory Honda Service Manual , it will save you so much in time and heartache , such as what you are going thru now .... , you can order one here .... or at you local Honda Dealer https://www.crfsonly.com/catalog/produc ... ts_id/3226
    2020 CRF450R
    2006 CRF450X
    Image
    Weiser , Idaho
  • familyguyfan84
    Posts: 3
    Joined: Sat Jul 04, 2020 12:34 pm

    Re: 05 CRF450x Missing Valve Parts On Running Motor? Newbie Questions.

    by familyguyfan84 » Sat Jul 04, 2020 3:12 pm

    JD,

    Thanks for the advice. I've already ordered a manual, but haven't seen it arrive yet. For now I've been looking online, and been able to find what I need. I'm not sure what he did with the motor before hand, because he has a history of getting a few too many, and tearing things apart. Even he might not remember.

    I'll order some new buckets today, and just park the bike until then. I've still got some troubleshooting I can do until then, with the starting system.

    I'm hoping that I dont need to replace the rod bearing, but maybe I'll send it out to have done. The valve was barely bent, and the piston looked like the carbon was hardly scratched, where it made contact.

    Do you have a good source for engine parts? I've found lots online, but not sure who to order with.

    Thanks!
  • User avatar
    JimDirt
    Posts: 4406
    Joined: Sat Nov 25, 2006 6:31 pm

    Re: 05 CRF450x Missing Valve Parts On Running Motor? Newbie Questions.

    by JimDirt » Sat Jul 04, 2020 5:03 pm

    You can get parts here (Ken is very competitive with his prices and he also does machine work , and has a good reputation in the business and stands behind his work) , that said (no I do not work for or gain anything from suggesting him , I am just a regular guy that hangs out here because of the atmosphere and good people , and wealth of information) you can find great deals on EBay , it is a place I frequent (I should be sponsored by EBay as I buy so much stuff from there . lol)

    Hopefully you picked up a HotCams Shim Kit as well , to help in getting the valves in spec , also , what is nice about these engines , is if the head is off , you can shim the valves while the head is on the bench , so basically , set it up , and install it ready to go as far as setting the lash and the cam goes , it would be ready to go when you go to set the head in place , just install the sprocket/timing chain and your done , it is a nice bonus feature of these single cam shim/bucket engines

    As far as the crank/piston goes , I worked on a DR400 one time and the owner had a valve touch the piston , it did not really leave a mark , much like you mentioned , I replaced the bent valves , and put the head back on (as per his request as he did not want to stick a bunch of money in the bike) , I fired it up , and bang , instant rod knock ..... since the added compression of the fresh valves/valve job , it put just enough pressure on the rod that the bearing let go , when I tore it down , you could see a flat spot on the rod bearing where it had flattened from the impact of the valve ....... not saying that is the case here , just stating that it can and has happened , so be prepared , if it does not let go , you are ahead of the game [-oo

    On a side note , I love my 450X and it is still on the original piston , , I got it new in 05 (its a 06 but I got one of the first 06's in my area) , I did put Stainless Intakes in it , and have not had to adjust a valve since , did the same to my 450R .... ;)
    2020 CRF450R
    2006 CRF450X
    Image
    Weiser , Idaho
  • familyguyfan84
    Posts: 3
    Joined: Sat Jul 04, 2020 12:34 pm

    Re: 05 CRF450x Missing Valve Parts On Running Motor? Newbie Questions.

    by familyguyfan84 » Sat Jul 11, 2020 10:12 am

    JD, you might have been more correct than I wanted you to be. Got it all back together again, and its clanking like a bastard. I'm going to be out of town for most of the rest of the summer. I'm going to take it to the local bike shop and tell him to check it out. I'd love to keep working on it, but wont have the opportunity to.

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