Front end slippage

Is the bike rolling or the back tires spinning faster than the fronts?

The tire speed can't be over 10kph (6mph) difference between front & rear for it to ingage ..

Nope, from a dead stop. Typically what he does is run in 2WD until he gets stuck or starts spinning. He lets off of it...shifts into 4WD...and gets back on the gas and waits for it to engage.

its fine. you have to almost be at an idle before the front end kicks in which is a good thing because you wouldnt want the front end kicking when the rear tires are spinning 20mph because thats how stuff tears up and makes us hondas look like polaris cough raveer cough cough

that is very true if the rear-end is spinning like a mad man and then all of a sudden the front end catchs you talking about a dusted diff that would definatly do it

Nope...This happens when he is starting from a full stop, and engine idling. I saw him try to crawl over a log. He pulled up to it in 2WD, stopped completely, switched to 4WD as it was idling and attempted to climb over it. The back tires started spinning, and continued to spin for 5 to 10 seconds before the front kicked in and pulled him up over the log. I'm thinking it has to be something electrical...maybe a bad sensor or bad connection???