JD Themed GT2A-S, 4 stroke

Finally getting back to doing some work to my bike. Changed the saddle a while back and added a layback post from sportscarpat with a 25.2 to 27.2mm shim. This weekend I did the AGK airbox mod to the stock box. I bought a sheet of UNI fine foam, something like $11 shipped from Amazon, the black square is my stock filter, so this is enough for roughly a gazillion filters.



Oiled and put in place in the stock box:


Then hollowed out the internal fins and punched out some breathing holes into the cover:


The invisible part is I drilled out the jet to a 72 bit as per AGK's writeup. Took it for a ride and the throttle response was defintely a bit peppier, and it's not starving for fuel at the top end anymore, it will roll up to 8300 rpm, which I backed of of quickly since red line is 7800 on these. BUT, it's not starving at 7800 anymore, so that's sweet. Next up I need to do a proper plug chop on it to see how it's behaving, but it feels pretty good, so I'm hopeful I may be able to drop down to a slightly smaller gear soon.

Here it is with it's big brother:

Thanks! It's been pretty solid. I commute to work on it on nice days, I've got about 250 miles logged on it this year.

If I could rewind and do it all over again, I'd still pick the 4 stroke. However, I'd buy just a bare motor and buy the rest of the parts separate. Once I got the CDI worked out on the motor, the motor itself has been solid. It's never so much as hiccuped, starts first pull every time and idles clean, I think I have somewhere around 500 miles on it total. It's the rest of the original kit accessories that have given me grief, all the aftermarket parts I've used have been great.

It's been a long time since I've checked in here or updated this thread. I just read through all of it again. I had a lot of fun working on this bike and a lot of frustration induced learning, followed by a few thousand happy miles with no major issues on this build. I just sold it last week to a guy who's wanted it for 3 years and I'm having a hoot of a time watching him update the build and make his own mark on the bike. I hadn't been riding it much, I started working on and riding full sized antique motorcycles so I could more reliably commute distance on 2 wheels. Been doing motorcycles for like 6 years now but it all started with this bike. So thanks for the ride folks!