After a ride I shut the engine off and the radiator fluid shoots out the overflow cap. There is a tinny hole in the cap and inner plug to allow this, but it happens often. If leave it run at an idle for a while and let the fan cool the fluid down it does not happen as often. Any ideas what is wrong?  

it sounds like the cooling fan isn't doing a very good job.
i think the best advice is to let it idle for a few minutes before shutting it down.