I just added 4 brand new stock size 25 inch Titan 589's to my 99 Eplorer 400, and i know they are like 5pounds heavier a tire then stock, and I noticed a huge difference in acceleration. I have a pipe installed and k&n air filter and yet it so sluggish. I only drove it for 4min, does it take time to break them in, like clutch spring or belt or whatever, i just dont get why it made a huge difference when they are still stock size? The weight for front tires are 22lbs and rear are 26lbs a piece. Thanks for the help.

 

I had the same power loss when I installed my 589's on the rear of my Magnum 500. It is due to the extra weight of the tires. Its like the difference between rolling a hula hoop and a cement hoop of the same size. Which one would you want to roll? The hula hoop is lighter and therefor rolls easier. The stock dunlops are the best if you want more power.

 

will a clutch kit or just changing the spring help at all? What spring do I change it to? Where can i get it? how much?