Mariner 200hp Relief valve

japdip

Cadet
Joined
Aug 24, 2008
Messages
6
Hi all,
i just bought a boat with a 200 hp mariner (1981, #5875429) and have a problem. The PO had a leak at the "figure 8" relief valve plate and had someone look at it who then removed the cover and guts if any, then lost it. This is how I purchased it. I had a 175hp sportjet block with the same figure 8 cover so I thought it would be an easy swap. No so clear now. The engine block on the boat is original to the midsection, but it does not have any connetion at the top of the block. The sportjet had a connection at the top of the block, but there were no springs or diaphrams behind the cover and the cover has never been off. I have read all the posts I could find, but cant come up with what the proper configuration should be for this engine. Do I buy all the components that fit behind the cover and install it without the relief line to the block, replace the cover without any parts behind it or what? Thanks for your help.
 

Dukedog

Captain
Joined
Oct 6, 2009
Messages
3,439
Re: Mariner 200hp Relief valve

Your '81 block is what is known as "first generation block". It is different in several ways from later year V6's. What your seeing is called a poppit. '81 had a round cover using two bolts and NO hose to top of tha block. Figure 8 or 4 bolts for mounting came on later blocks. So no hose is necessary. You can order a poppit assy. using your serial number but will need a dia. showing what goes where. Might be hard ta find exactly what tha parts book will show but basically all years 2.0, 2.4, 2.5 V6 poppit "internals" are tha same. Its tha 2 bolt and 4 bolt plates that are tha difference............

And yes, you need a poppit on a stock cooling system for it to do its job.......
 

japdip

Cadet
Joined
Aug 24, 2008
Messages
6
Re: Mariner 200hp Relief valve

Thanks for the reply, I'm still a little confused. The engine IS a 1981 (1st generation?), but it has the 4 bolt - "figure 8" cover and no block hose.
 

Dukedog

Captain
Joined
Oct 6, 2009
Messages
3,439
Re: Mariner 200hp Relief valve

If it does have tha 4 bolt pattern it still won't have tha hose to tha top of tha block. The hose bib (may or may not have it on tha figure 8 cover) tied into tha hose coming from tha heads to tha tattle-tell if it does. Tha hose from tha TOP of tha block deal didn't come in existance till '89. Is that a little better explained? Sorry for tha confusion.................
 

oldman570

Lieutenant Commander
Joined
Mar 25, 2011
Messages
1,615
Re: Mariner 200hp Relief valve

Check web site of Crowlley Marine as they have diagrams and part niumbers for your motor online, and a ph# listed there. They should be able to get you the parts needed if no one else can.
Oldman570
 
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