[jonathan180iq]

Pod filters require the removal of the air box. In doing so, you are eliminating some of the low end torque and baffling of intake noises that are created in the air box. I'm not sure what the air box theory is called, but it has to do with vaccums being created. This will also require a home made vent for the crankcase gasses, as they are no longer able to piped back into the air box. If you are looking for a little more juice while cruising, or on the top end, this mod should be pretty beneficial.

In doing so, the stock jetting will need to be adjusted to meet the demand for more fuel. A factory jet kit, usually supplied by an aftermarket company, comes in what are called "stages". They have stages 1,2,&3 depending on the mods done to a bike. For something like an air filter and a slip-on exhaust muffler, you're looking at stage 1 or 2 jet kits. These things contain several different jet sizes, needle clips, tapered needles and idle screw settings, depending on some R&D done of a specific bike. These kits usually sell for around $80. However, for us, we don't even get the option, as there is no jet kit available for the GZ250. This is why I am attempting to show you guys that you ca achieve the same results by yourself. It will require tweaking on more than one occasion, but that happens even with a factory jet kit.

I'll be using a "T" adapter which will connect the crankcase vent hole to an escape tube on one side and a small automotive crankcase breather on the other. The breather will keep out contaminants while the draintube will be a catch for the oil blow-by.

I'm not sure how these mains relate to the European model. In my service manual, there was only one bike that used a larger main jet than the 120. I don't know what model it was, but it called for a 122.5 main.

Also, it seems that there is a secondary tube that injects air into the carb. It's the seemingly useless black tube that runs along the top of the throttle side of the carb. That hole will be plugged.

I'll be removing the air box this evening and photos will be updated sometime tomorrow.