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Difference in HP500 Ignition Modules by year...???
Can anyone tell me the difference in the factory Mercury Ignition modules for the HP500 from 98 to 99.
The 97-98 are listed with a part# of 848821-2 which superseded to 840130a05, but the 99 is listed with a part number 840130A4. Does anyone know the difference between the two and if they are interchangeable? Thanks! 97-98: http://www.mercruiserparts.com/Show_...RU+0L001772%29 99+ https://www.mercruiserparts.com/Show...CAL+COMPONENTS |
I am not 100% on this.... I was on the quest for one years ago. All I knew was that I needed the module that had V8-HP on the module. I shopped around for one and i saw them mounted on different brackets or not at all. Perhaps part number changes due to mounting? Mine is mounted on my distributor but the one i got was on a bracket. I just took it off...
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Well I got off the horn with Merc Racing. They answered all my questions. But for reference if anyone wants to know, here it is:
The 840130A05 (more expensive) is a kit that contains the same module as the 840130A4 (which is updated) but comes with a harness adapter to work on the older 500 harness, this is the added cost. The GEN+ (99) harness was built to suit the newer module from the factory. In my case the engine harness is being replaced, so I can run the newer 99 Harness and the 99 model 840130A4 module (without harness adapter) on my 98 engine. |
I'm doing MSD boxes and just pulled my modules out this weekend. Oddly one engine had 848821-2 and the other had 840130-3 along with the slightly different harness setup to accomodate them. As far as I know both were original motors but the engine serial numbers on the build sheet from the factory are way off. I asked Formula about this a few years ago and they said it was not uncommon if they didn't have 2 identically produced merc hp500 motors in inventory when thw boat was built. In my case it sounds like they used one 1998 motor and one 1999. There is a second module labeled AZCA 16168749 that was in there also which was identical on both motors - anyone know what that is?
Originally Posted by SmurfOnABoat
(Post 3938146)
Well I got off the horn with Merc Racing. They answered all my questions. But for reference if anyone wants to know, here it is:
The 840130A05 (more expensive) is a kit that contains the same module as the 840130A4 (which is updated) but comes with a harness adapter to work on the older 500 harness, this is the added cost. The GEN+ (99) harness was built to suit the newer module from the factory. In my case the engine harness is being replaced, so I can run the newer 99 Harness and the 99 model 840130A4 module (without harness adapter) on my 98 engine. |
Originally Posted by Joe308
(Post 3982770)
There is a second module labeled AZCA 16168749 that was in there also which was identical on both motors - anyone know what that is?
16168749 Knock Module (454 PFI & TBI) $ 57.90. http://www.pdfio.com/k-2304233.html |
Ok so I assume that if eliminating the stock merc thunderbolt ignition with msd neither of these modules is needed?
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