6265 - Full Mod 28.5cc G290RC 4 Bolt Long Block

This engine now comes with a TR/OBR billet crankcase at no extra cost. This is a brand new full mod Zenoah 4 Bolt 28.5cc G290RC long block. This is a great way to pick up a full mod 4 bolt engine and save some cash. To use this long block you will need a flywheel, coil, covers, carb, clutch. All of these items can be removed from your stock engine and installed on this long block. Our long block comes with a complete 4 bolt Zenoah crank case with bearings and seals, stuffed crank, full mod top end. All long blocks come assembled as shown in the picture. With the higher reliability of these new 4 bolt Zenoah engines we were able to get more power with out sacrificing reliability. We put all of the knowledge that we have picked up from years of dyno and field testing and came up with a monster. The following port work has been done:

1. Deck cylinder for higher compression with out using a thinner base gasket
2. Reshape piston
3. Lighten piston
4. Relieve piston to prevent seizing
5. Modify intake port for better flow
6. Adjust intake duration to our specs
7. Resurface all ports
8. Modify transfer ports for better flow
9. Enlarge and reshape exhaust port
10. Adjust exhaust duration to our specs
11. Re-bevel all porting and stock bevels to prevent damage to the piston and/or cylinder.