[xpd153]

Recently I experienced starter relay problem at Futura. And I fixed it.

Then  I checked RC27's starter relay today.

At off, there is 5.5M ohm between B and M terminal.
At on, there is 1.7M ohm between B and M terminal.

I decided to dump this starter relay even RC27 did not have starting problem. I was not satisfied with sound of the starter.
I ordered cheap compatible parts to China. Because Futura has no problem and time is on my side

For the reference, I described about pin assigments of control terminal.

                            FUSE
                         1            2
                         3            4
                  -----------------------
                   |                         |
                   |     M           B   |
                   |                         |
                   |                         |
                   ---------------------

1 and 2 are NC
3 = 12V
 4 =GND
 
 For testing, you need regulated DC supply.

[robvangulik]

I assume that picture is of your actual contacts?
Looks clean enough, the problem lies usually in dirty contacts, I've also seen rust inside the relay.
I still have the original relays on all my Honda's, all work as they should, even at their advanced age

[xpd153]

The control terminal connector sealed its coupling.
However, B&M teminals have just rubber covers. But it may be ok.

I think true problem exists inside. At off, resistance should be infinity ohm. At on, it should be zero.

At this point, I think cheap new Chinese parts is better than 32 years old genuine parts.

[robvangulik]

Starter relais/solenoids aren't really factory bound, I fixed a friends' Yamaha once with the relay from a lawnmower