ignition unit

[newrider]

will a cdi box from a 1980 xs11 work for a 1979 xs11? original part number TID14-01 2H7-10, 1980 part number is TID14-04 4R0-10.

THANKX

[TopCatGr58]

Hey NEWRIDER,


A True 80 TCI would work cause it also would have the same prefix, 2H7. However, the one you stated was an 80 is actually an 81...note the 4RO prefix, it has the centrifugal advance incorporated within the TCI, but still needs the vacuum advance.

The 2H7 series is plain, and needs both the centrifugal and vacuum advance. There was a recent thread, and it's since been made into a tech tip, on how to replace the early TCI's with a couple of GM HEI ignition modules fairly cheaply, but requires a "LITTLE" wiring ability!
T.C.

[newrider]

will using the '81 box on the 79 motor do damage?

[TopCatGr58]

If you don't lock the mechanical centrifugal advance mechanism, I would imagine that the 4RO box in comination with the action of the cent. adv. would generate too much advance, and make it run poorly if at all. You will need to either remove the weights, or find a way to secure them and the timing plate so that it would not turn/slide when the weights are spinning. The timing plate does still need to turn/rotate with the action of the vacuum advance module, though!
T.C.