After noting that the level of the antifreeze in my rad overfill bottle gradually decreased after my 2003 600 Sportsman was run for awhile I investigated and found that the antifreeze was leaking into the base. This presents a problem as I don't know where to look first. A reply to an earlier post indicated that one guy discovered a cracked cylinder on his bike. I was going to start at the head gasket and then the water pump seal. Do I have to take the engine out of the bike to get the head off as this looks like quite a job? Does anyone have any experience at this??
Thanks in advance.

 

You do'nt need to pull the engine. The water pump seal is not your culprit. There is a weep hole under the water pump housing. Coolant leaks external. Coolant would have to pass thru a sealed bearing to enter the crankcase.

 

Your problem is most likely the water pump mechanical seal. To check follow the hose that from the radiator to the bottom of the engine, this is your water pump. Look under the pump and you should be able to locate a hole which is slightly under 1/4" in dia. This is the water pump weep hole. Touch your finger on to the hole to see if engine coolant is present and if there is your seal is leaking. The mechanical seal will most likely leak a very small ammount coolant but not enough to drop the level in the overflow tank enough that it needs to be topped up.
Let us know what you find.

 

I have the drain plug for the base oil out of the machine and the oil drained into a container that I couldn't find any antifreeze in but after after a few days sitting with the plug out there was a very small pool of leftover oil with definite drops of antifreeze in it on the floor. The pool lined up perfectly with the drain. I will look at the weep hole for the waterpump though. Thanks