Spark Plugs
All About Plugs: Install, Performance, Heat Range, etc:
What to the numbers on my spark plug mean? NGK Part Number Designation
Reading your plugs:
Note: Reading plugs to help determine tuning state (rich/ lean) has be come more difficult with the wide use of ethanol in the gas we use. Best way to determine tuning state is to evaluate how you think the bike is running, and to know what the full setup is on your carbs (PMS, jets, needles, shims, other carb mods, etc). The tables in the section on Performance (Link to Tuning - Carb Jetting) compared to your settings, and perfomance should go a long way toward telling you if your set up is correct. When in doubt, post your concern to the forum and get the experts' help.
http://www.dansmc.com/Spark_Plugs/Spark_Plugs_catalog.html (Click blue number for close-up) from Jr. (emijun1983)
Autolite and NGK
Here is a cross reference for NGK to Autolite plugs: These numbers and brands are here for reference only.
Yamaha recommends the BPR7ES in your V Star 1100
NGK AUTOLITE
BPR7ES (5534) = 62 STOCK PLUG
BPR6ES (7131) = 63
BPR6ES (7131) = 64
BPR5ES (7734) = 65 HOTTER PLUG
Note: The R means it is a resistor plug - in a pinch you can get by without the resistor, unless you have or plan to run electronics.
From Cobb - website I found to X-REF stock NGK plugs to the Iridium equivalent...
http://www.sparkplugs.co.uk/pages/technical/NGK-iridium-cross-reference.htm
Other Information
Watch Your Plugs - Jack Phelps
Servicing Spark Plugs - Motorcycle Cruiser Magazine
Spark Plug Wires
The spark plug wire ends can come apart. Here is a picture of the sequence of all the pieces inside the spark plug end. These may also need to be cleaned from time to time.