Mercury/Mariner Tohatsu ECU 20HP EFI Four Stroke.

Part number: Mercury: 8M0135817 & Tohatsu:  3RS-06401

20HP ECU to fit EFI models:

Mercury Mariner serial number: 0R833820 and up.

Tohatsu serial number: MFS20E.

If you are in any doubt whether this part will be suitable, please contact us first BEFORE purchasing.

Thank you for looking.