Is it worth routing this to the air box if your going to be riding in deep mud and water? If so is there a special way of routing it?

i've never changed mine from the std set up tom and regularly ride in deep water.bare in mind thats the route the fuel goes if the bike is layed on its side,probably not a good idea having fuel flowing into the airbox!

Thats a good point considering the amount of time my bike spends on its side

I kept having grief with mud bunging up the breather on the standard setup causing the slide to stick in the 'fully up' position due to the vacuum (often resulting in the rider and bike to end up in the 'fully lying down in the mud' position).

I stuck longer tubes on and routed them up by (but not into) the top of the air box.

I've since heard of folks putting a slit in the tube about and inch or so long to avoid this vacuum problem, but I'm too lazy to try it as I've not lobbed it due to being stuck on fuul throttle since.

I had lots of problems with a KLX dying in long stretches of deep water when the breathers became blocked.
The bike would slowly cut out as if it had run out of petrol. As soon as it was clear of the water it would restart. Although I have had no problems with the CRM I have put a Tee in on the breathers so that the breather goes up as well as down. A big bonus was the car windscreen washer tube and connections I had bought for the KLX ,which did not fit, were perfect for the CRM.
I'd not heard of bikes sticking on full throttle, now that is