Taffy

it's in the 2003 manual. they left it off ithe manual in 2002. a mistake

Taffy

husabutt

I believe that #20 in your diagram is the O-ring that tends to fall out of the engine case when you remove the side cover. The parts manual says its 17mm O.D. so that seems about right.

To find the O-ring that sits right behind the water pump impeller, that should be replaced when freshening up the WP seal, you need to look at the " Driving Shaft Counter Balancer" in the parts manual because the water pump shaft is first and foremost the counter balancer shaft. They are one and the same. That is a 10mm x 1.3mm O-ring.

I would strongly recommend that you remove the side cover and at least replace the O-ring (on the balancer shaft ) (its a hard to find size that will not be found in a universal O-ring assortment), the 17mm O-ring in the case, the water pump bearing / oil seal and then the water pump seal.

The water pump seal is such a tight fit that you are going to surely damage the seal if you try to bash it in without taking the side cover off. The lip of the seal is very fragile and it is difficult to keep the seal from being cocked from one side or the other when bashing it in. It will catch on a grove in the shaft and nick the seal lip.

Other than changing a spark plug and engine oil this is probably the most important maintenance item on a Husaberg. Do it right the first time and you will have a leak free weep hole. The weep hole can also leak oil that's why you should also replace the bearing/oil seal and O-ring.