[breimers]

Tools needed.
1. Continuity tester.
2. Two jumper wires.
3. Fully charged 12 volt battery.
4. Starter Switch Relay
Click on picture to see exploded view.

[breimers]

Make sure you have good 30amp fuse in the starter relay.

Step 1. Hook black jumper wire from 12 volt negative post of battery to green/red wire of terminal.

Step 2. Hook red jumper wire from 12 volt positive post of battery to yellow/red wire terminal. when you hook this wire up, You will hear a click. This clicking sound is the contacts in the starter relay.
SAFETY WARNING. Once starter relay is activated, only takes a minute and it will get extremly HOT. Remove red jumper wire as soon as test is completed.

Step 3. Use your continuity tester on the large terminals of the starter relay.
B is battery and M is starter motor.

There should be continuity between the large terminals while the battery is connected, and no continuity when the battery is disconnected.
Walla thats a simple way to test a starter relay on a RC51 honda

Thanks for looking and more self help tips coming from BReimers.
If you would like to see a specific post send me an email. I may be able to help.