Hayworth

86 honda 70 fourtrax rebuild question's

4 posts in this topic

Newbee here and got a few questions for ya! I'm working on honda 70 and looking to find some aftermarket parts for it without going to local honda shop and spending a fortune. lol

I race karts here in NC and going to make a pit bike to ride around on and just wanting to hop it up a little.Just wandering if anyone knows where I could find a aftermarket cam with more grunt than a stock cam? My plans so far is to do some port'n and polishing on the head, boring out the cylinder and put'n in a little bigger piston. Can I get a piston and rings lets say .020 to .030 over? Also has anyone ever milled the head down for more cc's on these little motors? Would there be enough valve clearance if you did? Any help or advise would greatly appreciated! Thanks,,

Share this post


Link to post
Share on other sites


I moved this thread into the Honda forum, when you actually start the project, you can start a thread in the project room to document the process.

I always recommend Service Honda or Babbits online parts for good prices on O.E.M parts. As far as working on the machine, I know no one who has, nor have I. I do know that some parts may be hard to find. Although, most of these new knockoff m/c's and atvs use old Engines that are based almost entirely off of those old Honda motors, there may be some cross-compatability with parts, who knows.

Edited by DirtDemon

Share this post


Link to post
Share on other sites

Thanks for the reply. Right now I' waiting on parts to get here. I'm done with the port'n and polishing of the head and intake. I've milled the head down a few thousands to add a little more compression. Its funny you mentioned about parts interchanging. I was going to lap the valves in last night and noticed that the intake valve had all but pulled thru the seat. I got to looking around and found a GX 140 ohv engine in the corner. Pulled the valves out and wat u know they'll work! lol We use alot of parts off of the GX 140 -200 on our karts and can get parts dirt cheap. The oem valve for this 70 cost 20 bucks. The valve off of the gx, $5. lol

Share this post


Link to post
Share on other sites

Very nice, please keep in touch and let us know how everything goes. Feel free to post any pictures of the project as you go.

Share this post


Link to post
Share on other sites

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 sloundez
      Does anyone out there know where I can get a functional pair of wheel cylinders for subject ATV? Any suggestions welcomed. Thanks
    • By marcuslachance
      I
      I bought a Honda 250sx 1986 but the exhaust is broken. Apparently it's not possible to order a new one. I checked to order one on others compagny but there's noting.
      Do you know which exhaust it's possible to install. Is there a company who sold an exaust to fit on my 250sx.
      Sorry for my english
      Thank you
      Marc
    • By Npeters
      Im working on a old 1987 honda 125 4 wheeler in the school shop. It will start by getting pulled by another 4 wheeler but wont start with the pull start or Electric Start. When you pull start it it tries to start but when you try the electric start it just turns over but doesnt even act like it wants to start. The spark plug is dry and it shoots fuel out of the back(air filter side) of the carb. Weve had the carb off twice and it is complety clean. What are some things we can try?
    • By patricknperkins
      Ok, so got this thing, assembled, and even added acid/assembled the battery with a solid trickle charge and the battery is fine.
      As far as I can tell, I have checked all the fuses I can find, but I have ZERO power to anything. Even the console will not light up when turned to ON.
      Is there some sort of hidden parental/child disconnect or safety switch that I'm not aware of? ANY help would be appreciated.
    • By pickytar
      I have a Chinese Hybird 250 or that's what I was told it was. I found 17 numbers on the frame. Will these numbers tell me exactly what it is that I have? (I know that its a 2006 from a plate on the front)