Hi, I am new to this forum, just picked up a 2001 DS650 a couple weeks ago. Right away I did the once over on everything, including carb, valve lash, and all the tuning and adjustment procedures. Yesterday I was the first day that I was actually able to drive it. It starts well, and took me a while to get the carb into adjustment. Whether it's driving or idling, after a couple minutes the fan will turn on, and then after a couple more minutes, it will start blowing coolant out of the rad cap. It wont drain the rad, but after a couple hours of driving the overflow can went to 0, and the rad is prob half full.
I am not sure if it is actually overheating or if there is something else going on. If it is indeed running hot, then I am not sure what could cause it. Pipes wern't red. The guy i bought from said that he had replaced the water pump at some point.... I am worried he might have done this wrong.... perhaps its running lean, although I dont think running lean would cause it to overheat that fast. Everything on the bike is stock with the exception of the muffler, which is a '48 ford tractor muffler, so I dont think re-jetting is required, but I am still a little unsure. Any help would be great. Thanks

 

Ok, here is an update. Just pulled off the cover for the water pump. Impeller is there, looks okay, but I started the engine and its not spinning! The water pump is a direct gear drive to the cam shaft is it not? Or is it switched to the thermostat? When I try and turn it by hand it wont turn, as if the gear is engaged, but wont turn with the engine running, what is happening here? Thanks.

 

Alright, final update... pulled the side of the moter, removed water pump assembly. The plastic gear that spins the impeller is missing about 40% of its teeth. I will order a new gear and that should solve my problem. Guess I didn't need help after all Thanks anyways!