mtnmanseth 0 Posted December 12, 2014 I came across this great article covering piston mechanics and replacement basics while researching my top end project: http://motocrossactionmag.com/news/the-tortured-life-of-the-piston-in-your-trusty-but-rusty-bike Share this post Link to post Share on other sites
Bagstr 288 Posted December 12, 2014 Now This a great Topic! Up there with " How to Set-Up your Suspension". Although,, I feel a need to call BS.. Esplain for me how a street motor goes forever on a piston and rings. And 2, why not my EXC? Bags According to this logic my 250 hr piston is toast. Share this post Link to post Share on other sites
PbdBlue 46 Posted December 13, 2014 Modern 4 stroke dirt bike pistons have really short skirts. When they wear the piston will start to rock in the bore and eventually bad things will happen. That said most mfrs way understate the lifespan. 250 hours is no problem if you're not racing. Just remember it's way cheaper to replace a piston proactively than after disaster strikes. YMMV. Share this post Link to post Share on other sites
Spaugh 1 Posted December 13, 2014 Dirt bike pistons wear out faster for a few reasons. 1. You can ride the rev limiter and the wheel spins, do this on a street bike and you will die. 2. Dirt bikes have 1 piston instead of 4. 3. Most important - dirt bikes eat dirt. WAY more dirt makes its way into a dirt bike engine than a street bike. Dirt accelerates engine wear. A LOT Share this post Link to post Share on other sites
