Anyone else want to feed their bike a little more air without removing the lid entirely? I've found that with the 130 main my bike is a tad rich, as evidenced by the very black/sooty license plate. However if I remove the lid its lean at 3/4 throttle. I could probably raise the needle up a notch and it would take care of it but instead I decided to hack open the airbox lid.
However I didn't want to just start cutting into the stock lid as I want to "tune" the air opening. Its easy to open it up farther, not so easy to put the material back on.

So I took some spare polystyrene (styrene, ABS, has many names) from my RC model parts bin and copied the stock lid, and then hogged out the air opening. The stock opening is 32mm X 86mm which gives a flow area of 3666 square mm. My new opening is 63mm X 82mm which gives me 5166 square mm, or 40% more area. I haven't run it yet, I'll be testing it on my way to work in the morning.

Anyway here's a couple pics.





For material it cost me ~$1 as the sheets are $2 at my local hobby shop and I only used half a sheet of the 0.08" thickness. I cut it out on my Ryobi variable speed jigsaw and it ate it like it was butter. Then I sanded/rounded the air inlet and made sure there were no square edges as I'm not sure what kind of suction that bike can pull. Had I just made a square hole and if the bike pulls enough vacuum it would just split the **** through the corners, you alleviate that by rounding the corners. I could go in detail on stress risers etc etc but I'll leave that for the office.

 

Hey Josh, nice job. Good old ingenuity at its best. Maybe you should start selling them.

 

P.S. what kind of laptop is that?[8D]

 

It's a roughly 4 or 5 year old Compaq Presario 2200, gets the job done for what little I use it for.

For anyone thinking of following my lead, with the .08" sheet you will need 1-2 washers under the bolts or else they'll just bottom out in the mounting holes and not tighten down on the lid. I ended up using 1 1/16" washer on each one to snug it down.

 

Awesome, Frankenstein strikes again.[8D]

 

Here's mine -- it's not pretty. That's the crankcase breather filter.

 

I just took the snorkel out like you reccommended... and its running good, 128 main... This may sound kinda funny, but if you really wanna "tune" the air intake... just take off the old lid.... and just cover the whole opening with duct tape, and cut out the size ya wanna try, that way you can try a bunch of different sizes, until you get it right.... duct tape is even a good babysitter.....

 

Yeah but with duct tape I don't get to play with my power tools

 

Best airbox lid mod I did was putting a shelf under it...man that opened it up

 

I noticed that it revved quicker from down low but not much different on top end. I'm thinking I need to raise the needle a notch and drop to a 128 main, ugh pulling the carb out is such a pain. At least I can get the needle just by taking off the tank.