valves chattering (any ideas??)

[400ex00]

i just reset my valves to a .004 and .006 setting and still no luck on getting the chatter out. this all started after installing my stage 1 hotcam. does anyone have any ideas on what could be causing this. ive already missed 1 weekend of riding and i dont want to miss another.

[swamprider7]

My friend has a raptor with a stage 1 hotcams and his makes valve clatter noise also. It is because it is a higher lift than the stock cam which cause the valves to slap back into place harder than a stock cam.

[Juggalo]

how does the stage 1 perform?i have one sitting here that i have not installed yet, i was just wonderin what you thought of it.

[400ex3]

The noise you're hearing is VALVE FLOAT. Even if the manufacturer says you don't need high performance springs with their cam, you will still need them. It's a safe bet that you need a spring kit with ANY aftermarket cam that is more aggressive that the stock one. If you don't do this, the valve seats will eventually be damaged, and the valve stem can actually fatigue (after extensive use this way) to the point that the head pops off and drops into the cylinder!!! No need to say what happens then....:eek:

I have found the extra clearence that hotcams recomends will be making some extra noise as well. I have tried to set the valves between the stk setting and hotcams and it did quite it down a little but it was still noticably louder than stk.

Mine did also slightly float the valves at the rev limiter etc but that has stopped with the new springs etc.

You may also just want to re check that they didnt losen up too.



how does the stage 1 perform?i have one sitting here that i have not installed yet, i was just wonderin what you thought of it.

Well from what I have seen the (not so) hotcams are pretty good on moderately modded 400's.

I think the stage2 would be better for a motor with higher comp to help the bottom end and also better for mx or top end. The stage1 would benefit a stk piston with other mods and a motor that would be more for trail or xc etc, but there isnt as much a diff from the 1 to 2 as they advertize and its almost splitting hairs and I dont see any major diff so dont pay a lot to what I said above. I believe the useage thing to be correct but there just isnt enough change in the cams to seriously worry about it.

Since I have been running one for a couple months now maybe I could help you decide what you want to do if you have more questions etc.