poppet valve question

[paulR]

hey don,new to this board.awesome site! can you show me a picture of this valve? is it just another thermostat in the lower part of the motor? why and how can i inspect it?2010 mercury 250 pro xs.serial #1B791586 motor has been flawless with the COCKTAIL and dfi oil.do i have a torque master LU? thanks.

[bloodman]

Heres my take on the poppit. Its a plastic valve on a spring that opens on pressure not temp. When you take off water pressure builds up in the block and forces open the poppit at about 2000-2500rpm allowing max cooling of the engine. The poppit is located on the lower right rear(starboard) side of the engine. You can look on lower right rear of block and see to bolt heads through oblong cover. This is the poppit. You need to remove lower cowl to access it. As long as you have the lower cowl off you should check the compressor screen which is on the opposite side of lower left side of engine. A hose that goes to compressor is attached and should be removed. The screen then can be unscrewed and comes out of engine. Clean it and replace. Don will give you more info, but thats a start

[taeheel2az]

What bloodman said.

IMHO, unless there's a symptom I'd just leave it alone.

When I did what you're talking about, I was careless replacing the poppet assembly, put it in with the lower cowl still on, got it a little out of line. and kinda forced it. Result was I knocked the robber grommet off the end, which fell down inside a water chamber. The motor would never heat up beyond mid 100s. In addition to risking the engine - I'd have likely blown it if I hadn't watched the SmartCraft gauge - I made a bunch of additional work for myself. Ah, well.

It should go in smoothly with little friction. It's easy to do it correctly, just keep my mishap in mind.

[EuropeanAM]

<table width="90%" cellspacing=0 cellpadding=0 align=center><tr><td>Quote, originally posted by bloodman &raquo;</td></tr><tr><td class="quote">Heres my take on the poppit. Its a plastic valve on a spring that opens on pressure not temp. When you take off water pressure builds up in the block and forces open the poppit at about 2000-2500rpm allowing max cooling of the engine. The poppit is located on the lower right rear(starboard) side of the engine. You can look on lower right rear of block and see to bolt heads through oblong cover. This is the poppit. You need to remove lower cowl to access it. As long as you have the lower cowl off you should check the compressor screen which is on the opposite side of lower left side of engine. A hose that goes to compressor is attached and should be removed. The screen then can be unscrewed and comes out of engine. Clean it and replace. Don will give you more info, but thats a start</td></tr></table>

+2

Paul... Welcome to BBC!

In the following link to the Parts Diaghrams for your engine, you'll see the Poppet Valve (Numbers 11-21). The compressor cooling inlet screen (#35) is shown on the other side of the adapter plate.

http://www.mercurypartsexpress...18256

One note: When chasing down cooling system problems- ALWAYS, ALWAYS start at the SOURCE: The Water Pump.

In fishing applications, water pump should be replaced ANNUALLY, or EVERY 100 HOURS, <u>Whichever occurs FIRST</u>.

Here's a link to some more useful information on recommended maintenance:

http://www.bbcboards.net/zerot...gines

BTW... your engine is likely equipped with a Verado-Style Gearcase. To verify... look at the leading edge of the gearcase, starting where it bolts to the midsection.

As you travel DOWN the leading edge (toward the "bullet")... there will be a 1/4" Jut-Out in the leading edge of the gearcase (on Verado-style models).

The Torquemaster, on the other hand, does NOT have this Jut-Out. It's also equipped with a 1-1/4" Propshaft, utilizies the Heavy-Duty (metal) prop hub, and has a torque tab "cast into" the Starboard side of the skeg at the trailing edge.