Does your starter relay Click click click? or does starter turn slow? You can gently hook up jumper cable to your battery to your cool truck and try to see if teh starter cranks freely. REMEMBER do not keep on the starter- you will fry the brushes. . The CRF 450X does not charge fast or put out alot of amps as your truck and yes you can just hook up the bike to a trikle charger, ie "battery tender". If you use a larger charger it might over charge the plates and fuse them together. a CRF 250X battery is a little less amps available it will fit(all they had in Holister-CA), I replaced mine and I did not have to, it was fine I had a burnt armature in teh starter, what a bitc* in removong, you need a small shallow skinny socket to get the one close to teh head. I bought mine in IDAHO, it was freezing there and mine had a flat spot in teh starter from day one, it woudl hang, the service dept. di dme a big favor and got it under warranty for me, gee you know it says teh CRF 450R/X are race bikes no warranty, well, it was a defect. I let mine set over 4 months and the fuel was bad, ALWAYS take a 17 mm socket wrench and drain teh fuel every time! these dont all have a screw to drain the fuel. go figure- there is a drain line tubing, no drain. FRESH gas is a must. temp does seem to be an issue s to reason to rejet or change anything unless you are in high altitudes ie 5000 AGL read Colorado KEEP OIL Changed and check valve clearances. I did mine @ 600 miles, and they are still in tolerance ( lucky me) I do change oil alot, it will serve you well that way. look into a "Billy Who funnel" and measure how much oil you remove and be sure to replace same amount. These high compression motors need best fuel around, NOT race gas From the Captn Bill