I don't suppose anybody has a 4B, or potentially a 4 or 4A ECU they want to sell?
Very rare and the only places that have them want extortionate money, so much so that its more appealing to rewire the engine and modernise the ECU..

Big difference between a 4. 4a and 4b, I take it it must be for a project, not a spare on existing twin engine deal or anything? I may have a regular 4 I would sell, Ill check and comment back on here IF I do, Smitty

Simple single engine boat, does have a TAC module though,no O2 sensors.
I'm not sure on the difference between a 4 and a 4A, don't need the CAN on the 4B though.

Suspected injector driver failure on a 4B.

Upgrading to a 6B and new harness isn't looking too expensive.

If you happen to find one it wont be cheap, dinosaur technology thats trippled in price, Ill text a bud of mine to see if he has one

I have managed to get hold of a 4B from eBay for a £500 which isn't too painful so long as it works! Now to get a map loaded onto it...