Taking her apart

[Dritto]

So, as I decided in my previous thread I'm going to take my 400ex fully apart, mainly because it needs a repaint, but I'll also do a few mods and maintenance.
This is my first time taking a 400ex apart, I've only once taken another quad apart and it was a Blaster.


First off I'll do maintenance like checking valve clearance, checking bearings and the condition of various things.
Next thing I'm going to do is mods, like removing the choke and installing HID lights.
But there are somethings that I'm wanting to know about before I decide. And before I start, you should know that I don't like to sacrifice durability.


As high compression ratio for 4-strokes is very effective, I'm think of putting a 11:1 Wiseco piston with stock bore (Btw I'll put all the links below). Is this a great idea? Do I need to change anything else than the piston, or adjust the valve timing and spark timing? I know this mod will put more stress to certain parts, but will this affect durability much?
A thing that a lot of 400ex owners do, is to replace the camshaft with a Hotcam stage #1 or #2. What does it really do? Is it just like a sprocket mod, increase top-end but lose low-end? Why do so many people do this mod?
I also seen some replace the timing chain with a crf250 one. Why's that?
Manual or automatic tensioner. What benefits will I get with this?
I went on Sparks website and found a 39mm FCR Carb Conversion Kit. What improvements are achieved with this expensive kit?


Are there any other mods that I should consider through out the quad?
As this is my first time parting an 400ex out, do you have any tips for specific items to check, replace and look out for?

I'll appreciate every help that I'll get, please feel free to post anything.


Links:
Hotcam 1/2/3: http://www.hotcamsinc.com/ProductSearch.aspx?page=1
Wiseco 11:1 piston: http://www.wiseco.com/ProductDetail....008&AppID=1202
39mm FCR Carb: http://www.sparksracing.com/39mm-fcr...trx-400ex.html