In the past a .26 engine installation in a TMax required many modifications and upgrades. Now, with the OFNA/Picco 26MAX (4.27cc) engine you have the first direct .26 TMax© 2.5cc engine replacement in the industry. The Picco 26MAX uses your existing Traxass clutch assembly, manifold, pipe & EZEE-Start System. This is not a simple .21 conversion, but a real .26 engine specifically engineered as a True Direct Replacement for your T-Max engine.