Hi Mickey. The eBay advert advises the following. "These advancers are designed to increase performance and improve throttle response particularly in the low to mid range as well as the starting of the bike. Bikes are designed to run as well as possible using the worst fuel available in the world and so have slightly retarded ignition to help with this. As we have relatively good fuel we can afford to run the bike with these 4 degree advancers fitted and have the bike run a whole lot better". Seems to work. Cheers, Rich.
The maximum is 4 degrees.
I thought they weren't recommended for the higher compression R1 engines. Might be wrong though, but thought I read it on Ivans' site.
IMPORTANT NOTE:Remember! This is an R1 motor. Ignition advancers are not recommended unless you have significantly raised the compression!http://www.ivansperformanceproducts.com/fz1.htm