I'm wanting to lay out my plans and any advice on the build like things I've missed or parts I haven't ordered that I'll need. I've got a baja warrior 196 clone no mods installed on motor just finished break in and torque converter installed. I ride ridges through the woods. I've ordered the stage 1 kit with a billet flywheel from OldMiniBikes. I'm not very experienced with small engine 4 strokes at all. I was an aircraft mechanic so I'm able and have plenty of tools available. I plan on removing the governor. And installing the exhaust and maybe trying the Jets that came with the kit. When I went to buy a billet rod there's about three different ones from OldMiniBikes. How do I know which one I'll need? And do I need a new piston head as well?
Hi Edd. I am far from an expert, but went through a similar conundrum myself a few months ago. I can answer some basic stuff.
1. The Arc billeted rods come in different lengths to account for different piston and heads (and even varying tolerances among units, since quality control on these engines are not super high)
There is a ton of info on this side from people much more experienced than I. That being said, the first thing to do is pull off the head to get a look at the piston. Once the piston is exposed, turn the crank until the piston is at TDC. Now see if the piston face sits flush with the block at TDC. It will likely be a bit short or "In the hole". If it is flush, a STOCK length rod is usually the most appropriate. If it sits low, you can use a micrometer or even stack feeler gauges up to determine the distance between the piston face and the block at TDC. A common one is 6256 Billet Rod, HF Predator +.020 3.328 (which means it is .020 longer to compensate for a "short" piston/rod).
You can do a ton of work on the head to increase performance, but that is better described in other threads.
Good Luck!