Samurai Distributor Vacuum Advance

IS your vacuum advance like most Samurai Vacuum Advance Diaphrams? If it is then most likely its not working. You can check them by applying a vacuum to them and seeing if they bleed off.

The Factory Service Manual states on inspection:

Disconnect vacuum hose from vacuum hose 3 way joint, and connect vacuum pump gauge to its hose. Apply vacuum (about 400 mmHg). And then with pump stopped, check to ensure that vacuum pump gauge indicator remains at the same level, and release it. Check that generator base plate with generator moves smoothly. If plate does not move smoothly, replace defective parts.

The defective part most likely is your vacuum advance. You could be loosing precious power from an "already deficient on power" engine.