Cam chain question


5 replies to this topic
  • exracer2

Posted July 08, 2013 - 06:22 AM

#1

I picked up a wr 426 in march of this year. When I first rode it, this bike would do 3rd gear roll on wheelies with ease. I notice the engine was quite noisie so I order a cam chain and installed it and checked the valves. The old cam chain was stretched real bad ,worst I have ever seen and surprise it didn't break. The engine also has a a Wiesco 13 to 1 piston in it and a decompression cam. After I put it back together the bike will not do 3rd gear wheelies as easy as before. The bike feels like my other wr400 and my yz426'. I am not saying its slow, It has just lost that little extra it had. Now could it be that the stretched chain gave me a better cam separation that enhanced the power? If I get an adjustable intake and play with the lobe separation I can find that lost power? Exracer2

  • 123devinzz1

Posted July 08, 2013 - 07:02 AM

#2

I picked up a wr 426 in march of this year. When I first rode it, this bike would do 3rd gear roll on wheelies with ease. I notice the engine was quite noisie so I order a cam chain and installed it and checked the valves. The old cam chain was stretched real bad ,worst I have ever seen and surprise it didn't break. The engine also has a a Wiesco 13 to 1 piston in it and a decompression cam. After I put it back together the bike will not do 3rd gear wheelies as easy as before. The bike feels like my other wr400 and my yz426'. I am not saying its slow, It has just lost that little extra it had. Now could it be that the stretched chain gave me a better cam separation that enhanced the power? If I get an adjustable intake and play with the lobe separation I can find that lost power? Exracer2


Are you running pump gas? 13/1 is stretching it on pump gas and it may have had high octane stuff in it from previous owner on your first ride.

  • grayracer513

Posted July 08, 2013 - 09:21 AM

#3

If it doesn't ping, octane isn't a problem.

The decomp cam you bought, was that for a WR or a YZ426?

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  • exracer2

Posted July 08, 2013 - 10:12 AM

#4

It did not have race gas and the cam was already in it. I just put a new cam chain in it. It will ping if I lug it but other wise it runs good, starts and idles great. It does warm up faster then my other bikes. It usually runs about 160 to 180 degrees. Exracer2

  • Krannie McKranface

Posted July 08, 2013 - 05:29 PM

#5

Your exhaust cam timing is off by one tooth (too close)

  • exracer2

Posted July 08, 2013 - 05:49 PM

#6

It's 13 pins and timing is set to hot cam marks.




 
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