82 40hp - Poppet valve squirting

[java230]

I have an 82 40hp 2 cyl 2 stroke. serial # 6141414

Its squirting water out of the poppet valve ( I think?! Thats waht the dealer had it listed under in his computer). What would be causing this? I just changed the powerhead to mid section gaskets, so i dont think its exhaust pressure in the water system. But i have no idea why i does it. Did it before the change. Doesn't do it on muffs, just in the water.

Is it just a bad valve? Could it be stuck? It has been in salt a fair bit. Impeller is nearly new, and it pees well, water is slightly warm coming out.

Its circled here.

Please help! I need to get this fixed before the weekend if at all posible.... TIA

 

[Chris1956]

Re: 82 40hp - Poppet valve squirting

Well, That is a poppit valve, and it should not be leaking. Look for an oring to replace, or maybe a gasket. The note on the parts list says an Oring is used w/o a thermostat. Do you have a thermostat?

 

[java230]

Re: 82 40hp - Poppet valve squirting

I don't believe it has a thermostat.

 

[java230]

Re: 82 40hp - Poppet valve squirting

Can i get rid of the whole thing or will that not allow the cooling system to build enough pressure at idle?

 

[mercurymang]

Re: 82 40hp - Poppet valve squirting

I had water coming out of mine and the diaphragm was compromised. I'm pretty sure that whatever is in there should be replaced with working components.

 

[java230]

Re: 82 40hp - Poppet valve squirting

I had water coming out of mine and the diaphragm was compromised. I'm pretty sure that whatever is in there should be replaced with working components.

Was it easy to fix? Im hoping to be on the boat all weekend....

 

[mercurymang]

Re: 82 40hp - Poppet valve squirting

No, but that's because I had a 30 year old poppet valve and broke off studs when trying to gain access. I'm thinking yours should not be that complicated. Is yours leaking out of the top?

 

[java230]

Re: 82 40hp - Poppet valve squirting

No, but that's because I had a 30 year old poppet valve and broke off studs when trying to gain access. I'm thinking yours should not be that complicated. Is yours leaking out of the top?

Yeah leaking out the top. Squirting a lot really. Ordered a new diaphragm.

Unfortunately I think mine will be breaking also.... It's an 82 motor that's seen salt. And I just replaced the head cover gasket and all 10 of those bolts snapped on me.....

 

[Texasmark]

Re: 82 40hp - Poppet valve squirting

In looking at that "coil mounting housing" I think I see 2 vertical holes, one larger than the other.......stats that I am aware of, are of a smaller diameter than poppets.

I know absolutely nothing about this engine but a little common sense here surely is in order.

Why would you have a poppet if no thermostat? What do you do with the water before the PO pops off? What if you just putt around all day and don't get to the higher rpms where the PO opens? You over heat your engine due to no flow if you ask me. What I think I see is a casting made for both. The stat controls the water flow as a function of temp at the lower rpms, and at the higher rpms, where volume is increased and a warm engine are not a concern, it allows additional volume to supply adequate cooling.

So, was there originally a stat too and might it be a consideration when replacing the popoff?

Just asking.

Mark

 

[java230]

Re: 82 40hp - Poppet valve squirting

Mark,
My understanding is that the poppet opens as water pressure builds with rpms. It opens to a larger passage to allow more water to flow and pressure to not build too high. To me it kind of does the same thing as a stat but is operated by pressure instead of temp, and changes the volume of water flow.

I don't believe i have a stat..... But I cant be sure until i get in there. It doesn't come up on the dealer computer with my serial number.

 

[mercurymang]

Re: 82 40hp - Poppet valve squirting

Looking at a parts diagram for your motor, it lists one. Looks to me like it sits right underneath the poppet.

 

[java230]

Re: 82 40hp - Poppet valve squirting

Where does one find this diagram? I can't find it.

 

[mercurymang]

Re: 82 40hp - Poppet valve squirting

Mercury, Mercruiser, Force, etc. - CYLINDER BLOCK AND THERMOSTAT - MERC 40

 

[java230]

Re: 82 40hp - Poppet valve squirting

thank you

 

[jslu]

Re: 82 40hp - Poppet valve squirting

Can i get rid of the whole thing or will that not allow the cooling system to build enough pressure at idle?[/QUOTE]

java,

if you follow the trail of these engine blocks at **********, you will see the blocks are essentially all the same relative to engine cooling passages in the blocks up until 1989.

In 1984 the HP rating of these engines was was changed from 40 to 35, difference being 40 HP rated at the crankshaft and 35 HP being rated at the prop shaft, essentially no change. Also in 1984 the thermostat and poppet valve and associated pieces were removed from the design for these blocks. A different cover and "O" ring are used. I have a 1989 35 HP that runs just fine without a thermostat and have converted a 1982 35 HP to operate just fine without a thermostat. I prefer "no thermostat" config, more reliable, less chance for overheat issues.

John

 

[mercurymang]

Re: 82 40hp - Poppet valve squirting

you can but more than likely it would be a bad idea. your motor will run too cool.

 

[Texasmark]

Re: 82 40hp - Poppet valve squirting

Can i get rid of the whole thing or will that not allow the cooling system to build enough pressure at idle?

java,

if you follow the trail of these engine blocks at **********, you will see the blocks are essentially all the same relative to engine cooling passages in the blocks up until 1989.

In 1984 the HP rating of these engines was was changed from 40 to 35, difference being 40 HP rated at the crankshaft and 35 HP being rated at the prop shaft, essentially no change. Also in 1984 the thermostat and poppet valve and associated pieces were removed from the design for these blocks. A different cover and "O" ring are used. I have a 1989 35 HP that runs just fine without a thermostat and have converted a 1982 35 HP to operate just fine without a thermostat. I prefer "no thermostat" config, more reliable, less chance for overheat issues.

John[/QUOTE]

Problem I see with no stat is that any water outlet prior to the top of the top cylinder at low rpms can prevent the top cylinder from being completely covered and I don't think that's a good idea, even at low rpms.

Yes the poppet is pressure regulated. My '02 90 triple has both. The stat opens at 143F. At 2500 rpms the manual says that the water pressure forces open the much larger poppet and the volume of water is greatly increased. I know that to be the case.

On my first outing after purchasing my current boat, I was operating at low speeds initially and got an OT warning. Not knowing what to do, I figured if I was getting hot, some ram water would help the impeller produce water pressure. So I firewalled it and after a minute or so, the alarm quit. I didn't hear it again till I was coming back to the no wake zone where I slowed and sure-nuf it sounded.

Got home put the stat in a pan of water and it didn't open. New stat and problem disappeared.

Mark

 

[java230]

Re: 82 40hp - Poppet valve squirting

I don't have an alarm. Everything is salty. May replace the stat at some point...


But new diaphragm and no more leaking all weekend.

 

[Mercniac]

Re: 82 40hp - Poppet valve squirting

I have the same motor, 1982, 2 cyl 40 hp, I think I'm confused, my motor had a small leak at the poppet valve cap, I removed the cap and the t-stat, t-stat looks pretty bad, I would prefer to remove the t-stat permanently but after reading the above I still have 2 questions, can I remove it without any adverse effects ( overheating, etc.) and how do I convert it, what parts, a different cap? Etc.
Thanks

 

[java230]

Re: 82 40hp - Poppet valve squirting

I have the same motor, 1982, 2 cyl 40 hp, I think I'm confused, my motor had a small leak at the poppet valve cap, I removed the cap and the t-stat, t-stat looks pretty bad, I would prefer to remove the t-stat permanently but after reading the above I still have 2 questions, can I remove it without any adverse effects ( overheating, etc.) and how do I convert it, what parts, a different cap? Etc.
Thanks

From reading above, I don't think its wise to remove the T stat, because of the flow mentioned above. However, i think it would cause it to run cold, in cold conditions, rather than hot.

Now on the flow part, I think that is much more regulated by the poppet rather than T stat. Hence as RPMs increase, and water pressure increases, it opens to a larger passage to keep water pressure down and allow more flow.

If you do end up removing it, let me know how it goes. You can buy the vent less cover and o ring at a merc dealer i believe. Or just remove it all and leave the diaphragm.