Do I have thunderbolt IV or V?

[Nextelbuddy]

1996 mercruiser 5.7 serial 0F760044

attached is a picture of my distributor and it looks like there is only 1 module with one plug on the back of the distributor.

just trying to find out so i know how to handle timing of the engine when i go to do that.

thanks for the help!

i did try using https://www.mercruiserparts.com/bam/subassembly/31770/1939/40 by searching based on my engine serial but nothing i see necessarily says thunderbolt name specific. it just shows ICM modules and knock modules in the parts catalog.

 

[alldodge]

You have a TB5
The difference between TB4 and 5 is the module (item 26), the distributor is the same

https://www.mercruiserparts.com/bam/subassembly/31770/1939/40

 

[Nextelbuddy]

You have a TB5
The difference between TB4 and 5 is the module (item 26), the distributor is the same

https://www.mercruiserparts.com/bam/subassembly/31770/1939/40

May I ask how you knew it was TB V? was it looking at the picture or the engine serial number?

if I have TB V, that means I have both modules 26 and 28 correct? looks like #26 is whats on the distributor, where is 28 located? i looked near my manifold riders and didnt see anything on them like i have seen in other pictures i online.

 

[alldodge]

Without looking up the part numbers, I saw the knock module. The TB4 doesn't use module. That was the quick and easy

Not all TB5's also had the knock module installed. Now that said, your motor could have been changed back to a TB4. The TB4's are marked as such on the face, and they only have one connector

https://forums.iboats.com/forum/eng...-mercruiser-thunderbolt-ignition-systems-work