The more mud that gets in the motor, the harder it is on the brushes. But the titan motors are really cheap to replace, around $15 i believe. I've ordered some slash's, and I have a pair coming as soon as I send the payment. I just spent $1000 on my crawlers last week, so I'm waiting until I recoup the budget to pay for the slash's. I will be keeping one stock and I already have a Novak GTV/Velocity 6.5 brushless system to run on LiPo for the other one. Go to the electric section and find the slash videos, or just go to my profile, click on "find all threads by charliestheman" in statistics, and find my slash video thread.