I have been having some starter issues since dropping a new engine in. I think I have that sorted out now, but I have a question about the 90a relay used on the starter. The old engine was a 502 mag mpi and now is a carb 512ci. I was told that the 90amp relay that was on the original starter was an efi thing and is no longer needed. The relay I am talking about is #8 in the pic below. I have a new starter to put on, just need to know if I should put a new relay on as well or leave it off. Thoughts? Thanks guys

that is a fuse

Sorry, that's what I meant. Is it needed on a non-efi motor?

Does your motor now have a 50 amp breaker in harness ,up top

Yes it does

you really should keep that fuse in place. it protects the wire feeding the circuit breaker from the starter

Thanks Ned.

Even though you can certainly leave it there .Merc didn't use a fuse there on carb stuff .

The early 90's carb big blocks merc engines did not use this 90 amp fuse but started with all the EFi / MPI.

Next to set the record straight from Merc all CARB Mercruiser engines from 1998 to the death of the marine carb engine at the end of 2012 - that's the 4 banger / 4.3 / 5.0 / 5.7 carb engines all had this 90 amp fuse to the starter also. 1998 thru the end of 2012 All carb models from mercruiser 2 bbl / 4bbl and TKS carbs the 90 amp fuse was used at the starter to clarify.