if its jumping in and out of gear, its probably an adjustment issue,but its always worth taking these apart to look, never know what you'll find. my bike mushroomed pawls constantly, the motor had built-in gear-reduction, so the shaft was on the right, and i only needed 1 chain from the motor to the hub, that setup is what killed so many pawls, the jackhammer effect of the engine not being dampened by another chain/jackshaft(kit), the rear sprocket with it's three ears and clip-ring-thing, had slight play(as they all do) and the front sprocket was on a splined shaft that had a little play, all of those things helped to slacken the drivetrain on exhaust-strokes, and slam the pawls into the face of the drum on ignition, about a 100 times each second...something to think about when motorizing any pawl mechanism... i had a couple sturmey archers from different eras on it(whatever i found for free to get it moving again).i could take it's last hub apart to show anyone if they care, the symptoms were starting when i took it off, i know the tips of the pawls will be mashed. i talked about it on another thread, everyone said they've never heard of such pawl/freewheel/hub issues.check out the thread, because a couple different people with shift kits threw in 2 cents, and im hoping to have a change-jar full of people's mechanical cents on shifting. it was utility bikes/shift systems. the other problem i fought was heat, because i welded a big sprocket on the original rear sprocket, and had a small one up front, the gear mechanism that transfers all your power to the hub itself, and rides on the axle(which is hollow, and has two slots that run parallel the axle ...its strength is greatly compromised by heat....) spun WAY faster then it ever should have, and upon taking apart the bike's first hub, found the cage that held the gears was bowed-outwards and had a heat-tint on it, i couldnt believe it held up at all. after that i filled them with gear oil, which leaks out slowly, and is kinda messy, but it was better then cookin them.