2000 yz426 engine? slapping noise
Posted April 13, 2008 - 05:51 PM
Posted April 13, 2008 - 07:10 PM
just read you post again do you mean speed or rpm in nuetral, the jd jet kit will stop the stalling prob. you have it did mine.
Posted April 13, 2008 - 07:15 PM
Posted April 14, 2008 - 06:22 AM
Posted April 14, 2008 - 09:34 AM
In the first case, it could be just the usual cacophony of noises that these engines are notorious for. But there could be a problem, too, so it's a good idea to compare it to another 426 to see how much it sounds like all the rest or not. If it's a 2000 model, it could have a loose nut on the primary drive gear, which would let the balancer drive gear rattle on the key that holds it. If that's the case, it's fairly urgent that you fix it, but your parts bill will be about $10, including a gasket, not counting coolant.
If you here the noise under a load, it's more likely the rear chain slapping the swing arm. Normal, and nothing to worry about.