Wow I sure got lucky.

5 replies to this topic
  • bushy

Posted June 26, 2004 - 03:10 PM


Bike has new intake valves after having the chain jump a bunch of teeth on the intake cam and valves hitting the piston. I get the bike together, starts 3rd kick, and it rips. It sounded very crisp and strong while riding it for 3 hours, so I thought it was safe to take it out on the trail. I trail ride it for another two hours, then stop the bike to take a break. When I start the bike back up, there is a HORRRID tickslaptickslap sound from the engine. I shut it off imediately, and the kickstarter would not buldge. Great, the piston bent the valves again. I wasnt going to push this pig home, so I pulled the valve cover off on the side of the trail (thank god for brining tools), and sure enough its off timing. I fix the timing, and to my luck it has the same compression as before. Starts right up, and I thought it be too good to be true. When I stop and start the motor again, it makes the same terrible noise as before. When I turned the motor off and kicked it over with the decomp pulled in a few times, it starts right up. Weird, but I rode it home anyway. So I pull off the valve cover again, and its off timing. Thats even weirder, how did it run with a tooth or two off time on the intake side? It still has full compression when I timed it back right.

I'm guessing its the timing chains fault becuase it does look a tad loose and probally hasnt been replaced in 5 years. The tensioner is working fine too.

  • Satch0922

Posted June 26, 2004 - 03:18 PM



just to be safe I would put a chain and tensioner on it.

  • bushy

Posted June 26, 2004 - 03:35 PM


Sorry, forgot to mention I was going to order a new chain. Whats really the point of replacing the tensioner as well?

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  • Satch0922

Posted June 26, 2004 - 03:43 PM


tensioner have and do fail. They don't cost that much.

  • sirthumpalot

Posted June 26, 2004 - 04:26 PM


Check the drive sprocket while you're at it, that's typically the first sprocket to go (the small one on the crank).

  • crf450f

Posted July 01, 2004 - 04:41 AM


I agree, get's more wear, since it's spinning faster than :thumbsup: the 2 top gears.

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