Old member.....new boat!

[inaforty]

We just picked up this 1991 V 20.
She is a lake boat with no bottom paint. Transom is solid but both deck hatches need coring. Hull has typical bumps and bruises. Bimini needs repair. 175 Mariner looks almost new. Compression is even across. I'm going to do a water pump, thermostats and carb cleaning.

Any advise on servicing the carbs on this mariner.
I've done Evinrudes and Yamaha but never Merc.

[phatdaddy]

looks great, i'd change the poppet valve also. and probably the fuel pump. i'd also change the lower unit oil. i'd recommend using oem parts, not sierra or other look-a-likes. when u do the water pump, get the kit that includes the housing.

[macojoe]

looks great! good luck!

[inaforty]

Thanks phat and joe ,
Didn't know that this engine had a poppit valve.

Thanks to FERM!
I have pm him with question that he has been kind enough to reply to and help me with my search for this boat

What a great bunch of people we have here on V20 board!

Maybe I can help someone someday like I have been helped here.

[bgreene]

Very nice - what's meant by " coring the hatches" ?

[phatdaddy]

poppit valve is located on the starboard side, under the cowling pans. easy to change, but the pans are a pia, sorta. i've found a 1/4 long extension with a swivel and the right socket helps(either 5/16 or 5 mm, can't remember). i think there is 5 bolts.

ferm or spare will give you the right info.

[Kracker Jack]

Originally Posted by bgreene

Very nice - what's meant by " coring the hatches" ?

I think he means to replace/repair the core ply wood in the hatches.

[pansof5]

what is a poppit valve

[THEFERMANATOR]

Originally Posted by pansof5

what is a poppit valve

It's part of the cooling system. When the RPM's come up above around 2000-2500, water pressure inside the engine gets high enough it pushes the poppet valve open which bypasses the thermostats to keep the engine cooler while running under a load. Many outboards run hotter at idle than they do when running to allow them to idle smoothly, but not overheat under load. Mercury used a poppet valve, and most of the others used a spring loaded t-stat that pushed open when water pressure went up.