My son came home on leave from the Navy...for a week. He really wanted get some riding in before going back to the Carrier for another typical Navy Cruise...so he bought a used 2004 Honda CRF450. It was a race beater is my guess and we replaced the wheel bearings, Chain & Sprocket, air filter, oil & oil filter etc. Oil come out really dark as the prior owner didn't change it often enough..my guess.. but it was clean and so were the oil plugs. Overall it looks healthy. AND he got some ride time in. So it has served its purpose I guess. And he loves it to death.
Couple of questions.
1) It starts, idles and runs really strong. A really snappy power band and doesn't use any oil or have any other bad habits...but it does have what sounds like a valve rap at LOW idle that emanates from the very top of the motor, almost the valve cover and emanates loud thru the frame. A stethoscope probing shows the motor to be real smooth & quiet right until you get to that top part of the cylinder head/valve cover area..I can't decide if its a valve or a cam chain slap. The rap goes completely away as soon as the RPM's pick up. What typically needs maintenance on those things up there that will "rap" at idle when out of adjustment?
2) The power is SO abrupt, almost explosive. He loves it..I think he would be better with a better transition from no throttle to explosion! Any idea's how to calm that monster down a bit? Its perfect for a track but rough in the woods.
3) What else should we look at on those '04's to get ahead of the wear & tear maintenance curve?
4) How much difference is there from the 04's to 07's?
Couple of questions.
1) It starts, idles and runs really strong. A really snappy power band and doesn't use any oil or have any other bad habits...but it does have what sounds like a valve rap at LOW idle that emanates from the very top of the motor, almost the valve cover and emanates loud thru the frame. A stethoscope probing shows the motor to be real smooth & quiet right until you get to that top part of the cylinder head/valve cover area..I can't decide if its a valve or a cam chain slap. The rap goes completely away as soon as the RPM's pick up. What typically needs maintenance on those things up there that will "rap" at idle when out of adjustment?
2) The power is SO abrupt, almost explosive. He loves it..I think he would be better with a better transition from no throttle to explosion! Any idea's how to calm that monster down a bit? Its perfect for a track but rough in the woods.
3) What else should we look at on those '04's to get ahead of the wear & tear maintenance curve?
4) How much difference is there from the 04's to 07's?