Whats the proper way to shift from 2wd to 4wd.
what I have read on the internet is you can shift on the fly, but my manual says I must come to a complete stop before going to 4wd.
2009 brute force 650 SRA
got the same bike and had a few issues with this as well. the answer IMO is to slow to below 15 mph and flip the switch. the main thing your looking for is for all four wheels are moving at close to the same speed. i got stuck in a mud pit in 2wd and tried to switch it to 4wd. the clanking sound that proceeded from my front diff didnt inspire alot of confidence. my brother makes the mistake of flipping the switch while he's nailing the gas which is a good way to grenade the front diff.
I keep mine under 20 mph. If your stuck and which it I would stop and then switch it and slowly bring up tire speed to no more than about 5-10 mph until it shifts into 4x4. You may have to this a few times.