My TM has been very durable and after 3 gallons of 30% nitro still has good pinch and makes great power. It's very easy to tune and stays in tune. It's also quite a but more powerful that the 3.3 trx. I just had mine apart converting it to bump start only and the bearings were in perfect shape with no sign of leakage from the front. Great drop in replacement but it is rather pricey.