There is a cross-reference to a Honda car (late 90s Civic I think) t-stat that will fit the ST1100. Since there are a lot more Civics than STs around Stant and several other aftermarket companies make t-stats to fit. Someone here can probably produce the Stant part number.
One can buy "fail-safe" type t-stats for many cars, maybe they are available for the late 90s Civic too. MotoRad (
http://www.motoradusa.com/index.html) makes these fail safe ones. I looked up the number for a '98-'99 Civic Ex and got this:
Fail Safe Thermostat 7328-170 170 degree. O.E. Recommended Temperature
You'll want to confirm whether this is the car and engine the ST1100 shares a t-stat with to be sure first.