Mercruiser Distributor Cap

[20pilot]

I found a crack in my distributor cap on my mercruiser 350. Could someone please identify the cap? The only markings say Delco-Remy, not part number or anything. I have never seen one with the box on the top. I don't have any model number on the engine, it was just a rebuilt 350 with aluminum intake manifold edelbrock 2506. Any help would be greatly appreciated.

Thanks

 

[Fun Times]

Hi there, do you have an over all photo of the top of your engine showing the distributor housing with cap removed, and the ignition module?

That style cap is not normally used. What year would you guess the engine to be? Boat year is?

 

[Bt Doctur]

that's a auto style cap, and if you have the auto dist you must change it out

 

[grewvin1]

Go to Google Delco Remy images and you will see this cap it would appear this might be an automotive dis. someone has put in or the engine is out of a car or truck. I've never seen this style in a boat but always can learn something new in 60yrs.

 

[Scott Danforth]

it MAY be a DUI (Davis Unified Ignition) which is based on the HEI, and they do offer a marine version, however I thought all their marine caps were blue. Most likely it is an automotive cap. if you see a vacuum canister on the distributor, it is automotive and needs to be changed to a proper marine distributor.

 

[Bondo]

it MAY be a DUI (Davis Unified Ignition) which is based on the HEI, and they do offer a marine version, however I thought all their marine caps were blue. Most likely it is an automotive cap. if you see a vacuum canister on the distributor, it is automotive and needs to be changed to a proper marine distributor.

Ayuh,.... Agreed,... If it's got a vacuum dashpot, it's gotta go,...

 

[20pilot]

No Title

Thanks for the help guys. I want to put a marine one on, this is just what was used when I purchased the boat. Here is a picture of the distributor/intake.

 

[Scott Danforth]

that is an automotive distributor and it needs to be replaced. can you take a larger photo, I do not see the J-tube on the carb. your carb may not be a marine carb either.

while at it, check to make sure the core plugs are brass and not steel. also check the starter and alternator for a tag or sticker that says SAE J1171 (marine certification). lets make sure the whole motor is not an automotive motor simply dropped in. While the block, heads, and crank are the same (and in many cases many other internal parts). the external components need to be marine.

 

[JustJason]

That's a GM HEI automotive distributor. If you need to find that exact one, go to the autoparts store and have them look one up for a mid 80's chevy car, like a caprice. Otherwise, that system is not designed to work in a marine enviorement, not certified, and really not safe. I would replace it with a Delco Voyager system, which is marine certified.

 

[Blue Mist 97]

Davis (DUI) does have a marine distributor. Cap comes in 4 colors and clear. Part # M12720 with color code at the end (BL,CL,BK,YL,RD) for big and small block motors (max 7K RPM). Drop it in, hook up one wire (two if you use the tach lead) and ready to go. $319 shipped from the manufacturer thru Summit Racing. Also, if you have some mods on your motor, Davis will curve it for you per your motor specs.

I just put one in my big block. Very sweet and easy to install. Also, installed a set of their live wires. They come in colors also.

Link: http://performancedistributors.com/product/marine-dui-distributors/

 

[Scott Danforth]

Davis (DUI) does have a marine distributor. Cap comes in 4 colors and clear. Part # M12720 with color code at the end (BL,CL,BK,YL,RD) for big and small block motors (max 7K RPM). Drop it in, hook up one wire (two if you use the tach lead) and ready to go. $319 shipped from the manufacturer thru Summit Racing. Also, if you have some mods on your motor, Davis will curve it for you per your motor specs.

I just put one in my big block. Very sweet and easy to install. Also, installed a set of their live wires. They come in colors also.

Link: http://performancedistributors.com/product/marine-dui-distributors/

correct, DUI has a marine distributor, however what is in the picture is an HEI. the carb may be automotive as well. since the OP has stated he just bought the boat with a "rebuilt motor" the fear is that the PO dropped in an automotive motor with a shiney new intake. did the PO also use automotive starter and alternator?

 

[Blue Mist 97]

No Title

Agreed on the possibility of that motor being a ?drop in? automotive motor and everything that you stated should be checked. Obviously, the vacuum pot is one warning sign. Makes sense, if PO dropped in an auto motor, he probably didn?t use any marine parts.

The picture on the Performance Distributors website may be a generic photo, however, you really can?t tell the difference from the outside or that picture. The one you get is the marine version HEI, and is virtually waterproof and vibration proof. Marine distributor says ?Marine? right under the bold D.U.I. on the coil.

Here is an actual pic of the DUI marine version.

 

[achris]

HEAD GASKETS and water pump!!!

If that is just a car engine that's been dropped in, and I suspect like everybody else it is, then the head gaskets will be steel and need to be replaced as well. Also the engine circ pump will need to be changed. The car pump have a steel backing plate and a pressed tin impeller and the marine units have a SS backing plate and a cast brass impeller....