Thanks phat, one more question, I have seen switch boxes on Amazon,2 for 59,00 but they have a ground wire and I think mine are grounded to the block when you install them so I am Leary about getting them cause they have a ground wire and the Mercury ones do not have a ground wire ,it's grounded to the block when installed, what do you think?
The ones on Amazon are from CDI.

That s more of a Spare or Ferm question. I would not buy used ones, no matter how cheap.

As far as the grounds, I think mine grounded through the mounting bolts

Phatdaddy, they are brand new 2 for 59,00 from Amazon , they are not quick silver they are from CDI an off market brand but the only thing that I see is that they have a ground wire and the quick silver ,Mercury brand does not have a ground wire . The boxes ground by screwing them into the block. They say they are a replacement and the price is wwhey cheaper

I used a CDI switchbox on a 40 hp i had worked great.

So have you definitely determined it is only running do 3 cyl
One box is for the port side and the other for starboard.

Sounds like you are still not sure what your issue is

Mercury switch box 275.00 each CDI 59.00 for a pair Amazon

CDI makes most OEM replacement electrical parts on these old engines now. The part that concerns me is Amazon is running over with counterfeit parts. They label them as good ones, but you get knock offs when they show up. I only buy from reputable sellers for that very reason.

Hey fermanator, I see you live in Florida,when you move to nj you are going to be my outboard mechanic. You will make a lot of money here. Not to many good outboard mechanics here.