new owner of MPI 502 mag; serial number? puking oil?

Fun Times

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The plastic arrestor would help narrow down a more round about year. My 96 454 MPI has the metal one. I recall telling myself years ago that the plastic was 1997 - late 2000 before switching to the 496/8.1L in 2001.

Also it's possible that it's the same original carbureted block but someone bought and installed just the MPI hardware back in the day. There was a lot of that going on back then with claims of getting close to an extra 5 MPH. Others removed the stock MPI system to add big carbureted blowers on their engines and sold the MPI hardware to help cover the costs.
 

bbender785

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couple pics i grabbed the other day to hopefully help:



is this the fuel cooler that was referred to above?:

 

bbender785

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thanks again for the input, good to know. sounds like a friend of a friend of a friend who is a well-respected local marine mechanic is going to give everything a once-over for me sometime next week, i'll report back with what we come up with.
 
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bbender785

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Have him brush up on his knowledge on the PCV hoses routings with this engine model before get's to your boat. Something doesn't look exactly right to me for some reason. I can't pin point it for you though.

as shown in my earlier pic in this thread both breather tubes had PCV valves and were T'd together and run into the intake manifold, but i have since corrected it to have one go the the flame arrestor without a PCV, just an elbow.

i did run it this weekend, and found that about 4000 rpm sustained is when the oil starts coming out. i got a slight whiff of it and got out of the throttle immediately, and checked under the sundeck afterwords and it did slightly haze the flame arrestor and the mirror on the bottom side of the sundeck. changed the oil with some 15w-40 last night, and the oil that came out of it felt pretty thin, so we'll see if that helps.
 

bbender785

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finally did some full throttle passes since changing the oil in June, and while it still blows some oil, it is much improved since the PCV reroute and 15w-40 oil. i wasn't able to connect with the aforementioned mechanic, hopefully yet this fall we'll get together. i'll probably pull the motor this winter and have it gone over anyways, since i'd like to redo the bilge.

i still need to figure out how to find the serial number on this thing.
 

alldodge

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I would suggest removing the PVC valve all together. Connect the hoses together with a Tee and have the open end of the Tee position under the arrestor. This is how mine is and I don't have much issue at all with oil. It does appear your engine is wore more then mine.

Edit: There should be a S/N plate above the starter
 
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bbender785

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Edit: There should be a S/N plate above the starter

i looked for that earlier this year per your reccomendation in your first reply to this thread, with no luck:

..as far as the serial number, i don't see said plate anywhere around there either; is it something stuck on the block or is it like an axle differential tag where its connected by a single bolt? that was the first place i looked, and after not finding it found the forementioned merc document about it being stamped onthe block. i'll look again.

i need to check the starter ground anyways, so i'll give it a look yet again.
 
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