OBR 5.5hp PROSTOCK Zenoah 4 Bolt 30.5cc Engine

Right after Baja Fest OBR had a huge sale on their engines. At first I was planning to go all out and buy the 27.2 full mod long rod engine. But the problem is the cost of those engines. I just cannot see myself drop over $500 for an engine, that is not including tax (they are located in CA). So I picked something a little more modest, with the option to upgrade later.

Here are some Dyno sheets:

Custom Mods

Just like all the other 2 stroke engine I had in the past I always epoxy a screen to the lower engine case to keep out the large debris from entering the flywheel area. I usually put the screen on the outside of the engine case because it was easier. But the problem with doing that is how messy it looked. But this time I actually took off the flywheel and glue the screen from the inside. It took a little more time to do it but the end result really pays off.

Cut part of a Hostile axle boot and used it as a seal for the carb's throttle shaft

Overkill RC billte coil spacer

GPM pull start cover