New head swap
  • Smidge
    Posts:8
    Joined:Mon Jan 27, 2020 10:29 pm
    New head swap

    by Smidge » Mon Jan 27, 2020 10:35 pm

    So I recently bought an 07 150r and it had a pretty bad clanking noise so I pulled the valve cover and checked clearances. One intake valve is complete zeroed out. The previous owner had valves, and cylinder replaced. And I think the cylinder may be sleeved as well. My friend who is a mechanic thinks it needs new valves and a valve job. I was thinking of getting the complete head with kibble white valves from crfs only instead of getting mine reseated and all new parts.
    My question is if I did this, what size valve shims would I use? Or will I have to use trial and error?

    Also how do I go about making sure my timing is right when I put everything back together.
    I've never completely replaced a head before.
  • User avatar
    JimDirt
    Posts:4406
    Joined:Sat Nov 25, 2006 6:31 pm

    Re: New head swap

    by JimDirt » Tue Jan 28, 2020 1:59 pm

    Welcome to the site !! \:D/

    The shims are going to vary , you can either get a Hot Cams Shim Kit , or send your tower/cam to Ken and he can set them for you (you can bench shim valves on a CRF as they do not need to be a complete engine to do it) , you can take 2 different brand new heads and they will shim out differently ... so there is not "install this size" thing , When it comes time to put the engine back together , there are several of us here that can walk you thru it ... What I would recommend is buying a Factory Honda Service Manual for it , if you plan on keeping it , the manual will tell you everything you need to know about rebuilding the engine , to servicing the suspension , to changing tires and adjusting spokes ..... and if you get stuck on anything , you can always just ask here , as usually someone is around that can walk you thru the issue .... ;)
    2020 CRF450R
    2006 CRF450X
    Image
    Weiser , Idaho
  • Smidge
    Posts:8
    Joined:Mon Jan 27, 2020 10:29 pm

    Re: New head swap

    by Smidge » Wed Jan 29, 2020 1:19 am

    Thanks for the reply! I have the owners manual, and the service manual. Owners manual actually has quite a bit of info! Much more than I expected, and much more than comes with my street bikes.

    I'm really hoping that the bike doesn't need a new piston/cylinder as well. The previous owner said "the noise has been there since we've owned it" (I'm the third owner). He did say the owner before him replaced the piston and valves, I'm also guessing that same person sleeved the cylinder because in the parts box I was given was an LA sleeve box with the old piston and valves.

    I had a few people tell me the noise sounded like cam chain noise and a few that said valves.vthe cam chain seems tight to me. One intake valve was zeroed, and one exhaust was out of spec. I'm really hoping the piston was not smacking the valves. And im guessing it's not bottom end because the bike has good power. I'd imagine bottom end failure would be accompanied by a lack of power. I have attached a pic of the la sleeve box, and a video of the noise I'm talking about pic is linked since I apparently can't embed pictures yet.

    https://imgur.com/gallery/ZON2Hs7
    http://imgur.com/gallery/Hpe3vcK

Who is online

Users browsing this forum: No registered users and 6 guests