Poppet valve '99 Merc 150 - Page 2

C YENSEN · #11 02-22-2007, 01:50 AM

Sorry.....but before this thread gets totally hijacked......I am sorry but I am not an OB guy. I have no idea what that valve is supposed to look like. I am sure Skools, or MJ will be along shortly. ;D

C YENSEN · #12 02-22-2007, 01:50 AM

Sorry.....but before this thread gets totally hijacked......I am sorry but I am not an OB guy. I have no idea what that valve is supposed to look like. I am sure Skools, or MJ will be along shortly. ;D

Blue_Runner · #13 02-22-2007, 06:46 PM

I don't know what they look like either but I found this

Poppet Valve Kit for Mercury:

Blue_Runner · #14 02-22-2007, 06:46 PM

I don't know what they look like either but I found this

Poppet Valve Kit for Mercury:

Blue_Runner · #15 02-22-2007, 07:02 PM

More poppet research. Commentary on someone elses problem:

Quote:

Did you check the poppet valve and springs?? Double-circular cover on the lower starboard side of the block, held on by 4 (maybe 5) bolts. I believe you will find it helpful to remove the lower motor cover on that side in order to gain access. The poppet controls cooling water flow for hi-speed operation, is supposed to unseat and flow max water around 2500 rpm's (?? I think).
-John

Quote:

This sure sounds like the poppet valve problem. When that valve is working correctly, you can watch the temp gauge climb to about 3/4 at high idle speed. At around 2500 rpm when water pressure builds, the gauge will drop rapidly down to 1/4 when the valve opens up, and the temp will stay down there up to WOT. Your new water pump eliminated that as a problem source, leaving other things to look for. Other than poppet valve, the other possibility is some kind of blockage in the cooling passages. Pulling the heads off and checking the water jackets is called for there. With a motor that old used in salt, replacing the head gaskets is not a bad idea anyway. Because it is easier to replace or clean the poppet valve assembly than it is to pull the heads, I would look at the valve next. Not sure about the big blocks, but with the small block V6s, you have to remove the lower engine cowl to get to the valve assembly. Problems like this are a process of elimination. With a used motor of unknown history, replacing these components as you go through the elimination process leads to peace of mind and confidence in your power plant.

Blue_Runner · #16 02-22-2007, 07:02 PM

More poppet research. Commentary on someone elses problem:

Quote:

Did you check the poppet valve and springs?? Double-circular cover on the lower starboard side of the block, held on by 4 (maybe 5) bolts. I believe you will find it helpful to remove the lower motor cover on that side in order to gain access. The poppet controls cooling water flow for hi-speed operation, is supposed to unseat and flow max water around 2500 rpm's (?? I think).
-John

Quote:

This sure sounds like the poppet valve problem. When that valve is working correctly, you can watch the temp gauge climb to about 3/4 at high idle speed. At around 2500 rpm when water pressure builds, the gauge will drop rapidly down to 1/4 when the valve opens up, and the temp will stay down there up to WOT. Your new water pump eliminated that as a problem source, leaving other things to look for. Other than poppet valve, the other possibility is some kind of blockage in the cooling passages. Pulling the heads off and checking the water jackets is called for there. With a motor that old used in salt, replacing the head gaskets is not a bad idea anyway. Because it is easier to replace or clean the poppet valve assembly than it is to pull the heads, I would look at the valve next. Not sure about the big blocks, but with the small block V6s, you have to remove the lower engine cowl to get to the valve assembly. Problems like this are a process of elimination. With a used motor of unknown history, replacing these components as you go through the elimination process leads to peace of mind and confidence in your power plant.

phatdaddy · #17 02-22-2007, 09:46 PM

RMB, how d id you pull the lower cowling pan. I need to get to my steering arm to clean and paint.

phatdaddy · #18 02-22-2007, 09:46 PM

RMB, how d id you pull the lower cowling pan. I need to get to my steering arm to clean and paint.

randlemanboater · #19 02-23-2007, 10:24 AM

Quote:

Originally Posted by phatdaddy

RMB, how *d id you pull the lower cowling pan. *I need to get to my steering arm to clean and paint.

There are 4 bolts holding the 2 pieces together, 2 in the back inside the cowling, one in the front inside and one in the front outside, right near the pivot point. I had to remove the airbox to get the front inside one out, the rest were no prob. The it is a rasslin (wrestling for you yanks) match to pull the covers off of the rubber mounts, for each side pull straight towards the sides of the boat

randlemanboater · #20 02-23-2007, 10:24 AM

Quote:

Originally Posted by phatdaddy

RMB, how *d id you pull the lower cowling pan. *I need to get to my steering arm to clean and paint.

There are 4 bolts holding the 2 pieces together, 2 in the back inside the cowling, one in the front inside and one in the front outside, right near the pivot point. I had to remove the airbox to get the front inside one out, the rest were no prob. The it is a rasslin (wrestling for you yanks) match to pull the covers off of the rubber mounts, for each side pull straight towards the sides of the boat