I bought a used 2000 DRZ400E in December 05 and set it up street leagal for Arizona, but ride mostly off-road two track with some single track. It runs strong but I've had problems with it boiling over into the overflow tank with some coolent ending up on the rear wheel when going slow on single track 1st gear trails or running up hill on two track roads that are washed out to the point that I have to run in 1st or 2nd gear. above about 15 MPH it runs fine with no boiling over problems. The cooling system has no leaks, however the left side radiator has been dented in the side in the middle of the core about 1/2 inch and the three outside columns pushed togehter. I've tried Red Line Water Wetter, but it made no difference.
When I searched the DRZ400 forum on TT I saw fixes that included: changing to a KX500 cap, installing a fan and Thermostat like the S model, and Jetting. Have any of you on the forum experienced cooling problems after minimal radiator damage similar to what I have? What order would you suggest trying the above mentioned fixes? What would you recommend for jetting for an E model operating at 5000 to 7500 feet elevation (I'm in Prescott, AZ).
Any thoughts or suggestions on what I try next would be appreciated.