From riding through the Winter there was quite a bit of mud in the radiator fins, any ideas on how to get it out without damaging the fins?
There are tools like THIS
one, made for straightening the fins. Would probably work for cleaning too.
I usually let the hose do the cleaning when I wash the bike. I try to get as much as possible from the back of the rad first, with the water pushing the dirt out the front. Once the water looks clean, I'll hose it off from the front.
But be careful with anything you use as a guard for the rad. It may not look like much, but even the stock guard restricts a good bit of air flow.
Just try it with a house fan. More than likely, if you take the front grill off, you'll get ALOT more air blowing.
IMO, the best type of guard would be something like dirtbikes have. Vents.
In all the mud and rocks kicked up infront of my KLX, I've never had a rad blow out due to flying debris.
Although, your 650 dualsport probably has a screen, doesn't it?