Tough to change cam chain in 99 WR 400?


5 replies to this topic
  • bultaco

Posted April 07, 2009 - 09:20 PM

#1

I am planning to put in an HotCams exhaust cam in my bike to facilitate starting...while I am in there it would be a good idea to change the cam chain...Never done this type of job before. Do I need special tools for this project?

The local shop in San Francisco quoted me 3HRS x $90/hour = $270 labor only to just change the exhaust cam and set valve clearances....Any insights appreciated.

  • Frostbite

Posted April 08, 2009 - 02:17 AM

#2

I am planning to put in an HotCams exhaust cam in my bike to facilitate starting...while I am in there it would be a good idea to change the cam chain...Never done this type of job before. Do I need special tools for this project?

The local shop in San Francisco quoted me 3HRS x $90/hour = $270 labor only to just change the exhaust cam and set valve clearances....Any insights appreciated.



It's a good idea to pop in a new cam chain. To do this you must remove the flywheel, and you need a proper puller for that. The universal 3 arm pullers aren't recommended. They pull on the edges of the flywheel and I have heard that this can bend the flywheel. You'll also need a new gasket for the flywheel cover.

As for changing the cam, it's not hard, but you have to be very careful setting the cam timing. There were times when I opened my 400 up when the timing marks on the sprockets seemed impossible to line up properly (due to stretched chain, new sprockets etc.) I bought a degree wheel to be sure, but the easiest way would be to set your engine to TDC and look at the timing marks before you change anything. Better yet, take a few digital pics of the timing marks. They are supposed to be level with the valve cover mating surface, but I don't think I have ever seen the marks on my intake and exhaust line up perfectly.

There are many great theads here on setting cam timing, and some folks count the pins in the chain. Now that I have a degree wheel I don't have any worries, but counting pins would also be a good idea. You can do a search for the proper number of pins between cams.

Finally, setting the valve clearances can also be a little tricky, and you'll most likely have to get a few shims from your dealer. If you're not mechanically inclined, it might be worth the coin to have the work done at the dealer, or it may be a great time to become mechanically inclined. It's always a good idea to know what's going on in your engine.

Cheers

Frosty

  • William1

Posted April 08, 2009 - 02:37 AM

#3

Cam chain swap is a one hour job, tops, very easy to do. Setting valve clearences is easy, an additional hour, at most. A good wrench could easily do both in about an hour. If your shop is hitting you for three hours just to set the valves, I'd look for a different shop.

As frosty says, you have to have a flywheel puller. They are cheap, about $20.00. You will also want to have access to an impact gun to loosen and tighten the flywheel nut.
When you pull the cam caps off, do it slowly and carefully. You want to keep track of the half moon bearing locator 'rings'. Have a magnet nearby.....

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  • flyer05

Posted April 08, 2009 - 09:47 AM

#4

Just did the same thing. Not bad at all, just like what was said, get a good puller and you'll be fine.
Good luck

  • bluebreadtruck

Posted April 09, 2009 - 04:22 PM

#5

very easy. just use a steering wheel puller you can buy at any auto parts store, Its nice having a new timing chain because the cam marks line up spot-on and much easier to time!

  • bluebreadtruck

Posted April 10, 2009 - 05:38 AM

#6

one other thing, once the flywheel is off, you will need a torx bit to remove the 3 bolts holding the stator, then a 10mm to remove the chain guide.




 
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