One day while dynoing to extract the last little bit of power from a Gazelle 60 TAG engine, a surprising power increase was noted when one simple change was made...
The dyno session was started with a 10 tooth driver whose teeth had that tell-tale hook shape that indicates tooth wear. After a few runs to stabilize temperatures, a few more runs were made to gather data for changes made one at a time to gauge relative performance of each. When that was all done there was some time left before the mandatory dyno noise curfew. So on a whim we changed the worn drive pinion for a new one with the same number of teeth.
The next run right out of the box the engine showed 2 tenths to 4 tenth more power across the rpm range! We couldn’t believe it!
There must have been something wrong. So thinking the engine was still cool and making more power because cool engines usually make more horsepower, several more runs were made to verify that the engine was well into the operating temperature range. Well, it was not a fluke. The worn drive pinion was soaking up almost half a horsepower at some rpms!
It turns out that the largest single power gain achieved that day was caused by simply replacing the worn drive pinion on the clutch with a new one. Imagine what that can do for your son’s or daughter’s lap times!
Whether they drive a kart powered by a Gazelle 60cc, a Yamaha KT100, Rotax FR125, Parilla Leopard... No one can afford to simply throw away horsepower. When your pinion gear teeth start to feel sharp to the touch or get that "Matterhorn" hook shape, it's time to throw out the O-Pinion!
The dyno session was started with a 10 tooth driver whose teeth had that tell-tale hook shape that indicates tooth wear. After a few runs to stabilize temperatures, a few more runs were made to gather data for changes made one at a time to gauge relative performance of each. When that was all done there was some time left before the mandatory dyno noise curfew. So on a whim we changed the worn drive pinion for a new one with the same number of teeth.
The next run right out of the box the engine showed 2 tenths to 4 tenth more power across the rpm range! We couldn’t believe it!
There must have been something wrong. So thinking the engine was still cool and making more power because cool engines usually make more horsepower, several more runs were made to verify that the engine was well into the operating temperature range. Well, it was not a fluke. The worn drive pinion was soaking up almost half a horsepower at some rpms!
It turns out that the largest single power gain achieved that day was caused by simply replacing the worn drive pinion on the clutch with a new one. Imagine what that can do for your son’s or daughter’s lap times!
Whether they drive a kart powered by a Gazelle 60cc, a Yamaha KT100, Rotax FR125, Parilla Leopard... No one can afford to simply throw away horsepower. When your pinion gear teeth start to feel sharp to the touch or get that "Matterhorn" hook shape, it's time to throw out the O-Pinion!
