tabernac.... I have the same problem and have researched. There are a few good links here if you search it.
If it's just the governor seal which is likely (can be taken off with an allan wrench, 4 bolts in total). The seal is about 12 dollars with post from BC to Quebec. Call Rocky Mountain Imports at 1-800-921-4JDM
There is also an o-ring kit best got from the UK if its more than just the one seal. The o-rings are quite generic and could be found from napa or lordco or a plumbing store?...but the gov seal is unique!
I just ordered both, but won't get to fixing it for a month. Here are the links for the o-ring kit from UK.... if need i may have extra o-ring kit early FEB.