Wow, where to start.
ok, first, don't be intimidated by lifting the tank and propping it
on the wand Triumph so thoughtfully provided.
Next, a service manual would be very handy
for some of these projects.
The decibel popping on deceleration is because you're not tuned exactly right.
Rich or lean can both be corrected one of several ways,
starting with the most expensive to the least.
1) tuneboy, around $600.00
2) dynojet PC 3 or 5 around 3-5 hundred depending which you go with
3) Dobeck EFI controller around $150.
4) tuneECU free except for the $16. cable.
a quick, easy, handy, cheap improvement is to get and install
is a Gi-Pro w/ ATRE.
It eliminates the 7% restriction from the factory,
plus gives ya a nifty gear indicator.
a Stebel air horn is the first improvement I did.
Fairly cheap and easy install.
Good luck on all your projects guys.
If I can help in any way, shoot me an e-mail.
My e-mail is firstname.lastname@example.org
and I check it every couple days.