RSGP125 BUILD3

Suzuki GP125 engine strip down

Here are some more internal photos of the GP engine as I pull it down. I ended up drilling most of the phillips head bolts which hold the casings together as they were corroded down the thread. What a stupid idea it is to use a phillips head, honestly.

This last photo is of the tiny GP gearbox assembly. I wanted to show it to give you an idea on how a motorcycle gearbox works (although similar to a car) in translating the up and down movement of the gear changer to a change in gear. When you push up or down on the changer, a mechanism spins the grooved barrel in the top of the photos. In those grooves are the gear selectors which move left and right depending on the groove. The selectors move the gears on the input and output shafts which engage with each other to drive different combinations of gears and therefore ratios.

RSGP125 BUILD1

I spent some time at Tim’s (a fellow F4 racer) place on Anzac day talking crap about bikes and figuring out how we can get some economies of scale going on with our GP125 builds. Being the good bastard he is, he gave me some… ummmm… used GP125 cases and a test bed GP100 cylinder for some time on the grinder before jumping into mine. THANKS TIM!
I started undressing her the other night and took some photos along the way:

Factory Suzuki GP125 crank case as provided by Tim

Tim’s degree wheel for port timing

Port side

Factory timing marks

Starboard side