I just changed thermostat and poppet valve on a friends Mercury 100 hp 2 stroke, someone had been there before, it had no thermostat and the 2 middle bolts had been snapped and glued in with silicone, couple of helicoils sorted that problem. The engine now runs better than ever, it used to smoke real bad and would,nt idle and rev up and down on its own.
Hi Striker, i really enjoyed your video and i would like to perform the maintenance by myself. Is it possibile for you to share with me the maintenance manual? Thankssss
i have a merc.150 efi , where is the poppet valve located at, i cant see it must be behind sevweral other parts i just cant see i think on starb. side low, may have to take off cwling
So are these thermostats directly in relation to the pisser? My 95 25HP will pee on and off, my guess is the thermostat only allows it to pee when it’s up to temp. Is this correct?
The telltale (pisser) should always be pissing as long as the motor is running. You may have mud bugs in the telltale or even a failing water pump. Water pumps should be replaced every few years, although I didn't do mine for like 6 years.
Oh, and also if you run it on the ear muffs it won't pee steadily, which is why I use a 55 gallon drum cut in half filled with water every spring. If it's not peeing steadily in the lake, you have a problem.
My change didn’t go well. The bolt above and below the diaphragm snapped. Water was getting past the diaphragm and out of the weep hole which is why I was changing the diaphragm. I would recommend anti seize on the bolts when replacing the cover to prevent a huge pain in the ass down the line.
This is a good tip. The blue loctite is recommended all throughout the manual but I don't believe they said anything about it for these bolts. They should.
grease is better. Many anti seize lubricants contain coppers and other metal alloys that will react with the engine metals. Sounds Ironic but, regular marine grease will work better in most cases. if you want to use an anti seize make sure it is a marine grade and does not have copper. Try researching "anti seize or grease for marine bolts" on forums like Thehulltruth.com
@@ReelTeaseFishing I use the silver anti seize, and not the copper. Both are available in the stores, the copper is generally for higher heat temps for dry use, like exhaust applications. Any locktight would NOT be advised for this particular application.
It depends on the serial number of your motor, the mercury website has a parts catalog you can look it up in. www.mercurymarine.com/en/us/parts-and-accessories/parts-catalog
I have a 2000 Elpto that I just got a 140 ° thermostat for to replace my old one. I got the thermostat, with rubber gasket, the big gasket that seals it all up and also a flat washer came in the package. Can you tell me where this metal washer goes ? Thanks, Tim
The shiny flat washer with the small hole in the middle is for the poppet screw, if needed. It flattens the poppet diaphragm. If just changing the thermostat, just throw it in the tool box. I recommend the "Thermostat Kit" I referenced earlier, change it all out while you are in there. Always test your thermostats, both old and new, on the stove in hot water with a thermometer, looking not only to open near temp - you want ALL THE WAY OPEN. The one I last replaced was not opening all the way.
Isn't 18 ft/lbs the recommended torque for the cylinder cover? The five thermostat cover bolts are 24 ft/lbs according to the Seloc manual. This for my 2002 90 hp 3 cyl but the cylinder cover is identical.
Just doublechecked. Page 4-56 of the Mercury service manual (part# 90-830234R3) says "Thermostat/Poppet Valve Cover Screws - Torque to 18.lb.ft (24.5Nm)"
I need to install my front cover and want to make sure I’m torquing to spec. 2003 mercury 90 hp 2 stroke. Mine are all common M8 bolts for the cover and therm cover. So is it 24 or 18 ft lbs?
I have to add something else. The diaphragm on my poppet assembly was placed in backwards. It didn't seem to fit right that way and that's why I came back to look at yours. I will not be going back to my last mechanic.
Also known as the "Sender", or "Sending Unit". They send ohms back to the gauge that vary with water temperature, and only work correctly with a paired gauge designed for that range of ohms. If your motor does not have one, there is probably a brass plug in the hole.
@@striker1211 my thought process is, it wasnt shooting water out of that port before and now it is and im certain it was never plugged. is there a chance i could have a PRV/poppet valve stuck open or a blockage somewhere?
Do you have a good place to find the thermostat gasket (black circular gasket)? I have a thermostat but can't seem to track down the part number online. Accidentally got a thermostat without the gasket. I plan to replace the thermostat and poppet soon. I have a 98 merc 115 elpto 2 stroke.
I'd recommend getting the serial number of your engine and looking it up in the parts catalog: www.mercurymarine.com/en/us/parts-and-accessories/parts-catalog . The closest thing I could find was part 27-62386 which is available on amazon, but it could vary since I don't have your serial number.
What does the poppet valve do I took my thermostats out and BOTH are in the OPEN(HOT) position when COLD I don't know how that could happen I'm soaking them in vinegar.
the poppet valve is part of the cooling system. Its a water regulating system. think about it like this. at low RPM's, or in idle there isn't as much pressure in the cooling system so the poppet valve stays shut. (Garden hose with thumb on the end to increase pressure/distance.) When the outboard is at higher RPM's the impeller is in higher RPM's too, this increases pressure & begins to open the poppet valve. Once enough water is going through the system to keep the engine at proper temp, the poppet valve opens completely. (Thumb off garden hose). Once the poppet valve is completely open it dumps any excess water out of the cooling system as to not over pressures the cooling system. (bypass) subscribe to us :)
The thermostat regulates water flow at idle (low water pressure). The poppet regulates cooling when the block pressure exceeds 6 psi. It is important to have a functioning thermostat, if the piston heats up faster than the cylinder wall you can get a cold seize and the motor will need a rebuild. Also, if the poppet is stuck open the water will not be able to build up pressure in the block at low rpm, and you could over heat. Additionally, if the poppet is stuck closed you could over heat at higher rpms since the cooling water is not allowed to circulate from the block.
You people are killing me unless you live in Minnesota and the lake in frozen you don’t need thermostats on a outboard they run cooler and that’s what you want in these old 2 strokes unless yours is computer controlled u don’t need them
Just got a new boat and water come out of the weep hole when revved up so I found your video. Should make this process much easier. Good video!
Where did you order your manual from
I just changed thermostat and poppet valve on a friends Mercury 100 hp 2 stroke, someone had been there before, it had no thermostat and the 2 middle bolts had been snapped and glued in with silicone, couple of helicoils sorted that problem. The engine now runs better than ever, it used to smoke real bad and would,nt idle and rev up and down on its own.
Guy throws that pinky out there like HaY'ee ova here bois''' 🤣
The wire on the top right is that for the temp gauge
Yeah, I have a video on the temp guage on my channel as well
got the exact same boat and motor good video
Hi Striker, i really enjoyed your video and i would like to perform the maintenance by myself. Is it possibile for you to share with me the maintenance manual? Thankssss
Are you seals gone on the poppet valve?
Did you get new poppet valve complete or just the diaphragm
It's been a few years but I am pretty sure I took this apart to check the thermostats operation and reused everything but the large gasket.
i have a merc.150 efi , where is the poppet valve located at, i cant see it must be behind sevweral other parts i just cant see i think on starb. side low, may have to take off cwling
So are these thermostats directly in relation to the pisser? My 95 25HP will pee on and off, my guess is the thermostat only allows it to pee when it’s up to temp. Is this correct?
The telltale (pisser) should always be pissing as long as the motor is running. You may have mud bugs in the telltale or even a failing water pump. Water pumps should be replaced every few years, although I didn't do mine for like 6 years.
Oh, and also if you run it on the ear muffs it won't pee steadily, which is why I use a 55 gallon drum cut in half filled with water every spring. If it's not peeing steadily in the lake, you have a problem.
My change didn’t go well. The bolt above and below the diaphragm snapped. Water was getting past the diaphragm and out of the weep hole which is why I was changing the diaphragm. I would recommend anti seize on the bolts when replacing the cover to prevent a huge pain in the ass down the line.
This is a good tip. The blue loctite is recommended all throughout the manual but I don't believe they said anything about it for these bolts. They should.
grease is better. Many anti seize lubricants contain coppers and other metal alloys that will react with the engine metals. Sounds Ironic but, regular marine grease will work better in most cases. if you want to use an anti seize make sure it is a marine grade and does not have copper. Try researching "anti seize or grease for marine bolts" on forums like Thehulltruth.com
@@ReelTeaseFishing I use the silver anti seize, and not the copper. Both are available in the stores, the copper is generally for higher heat temps for dry use, like exhaust applications. Any locktight would NOT be advised for this particular application.
Anyone know what that brass bolt and wire above the top right cylinder is??
Great video what's the poppet valve part num
It depends on the serial number of your motor, the mercury website has a parts catalog you can look it up in. www.mercurymarine.com/en/us/parts-and-accessories/parts-catalog
What's that part # for the gasket
It's 27-430068.
I have a 2000 Elpto that I just got a 140 ° thermostat for to replace my old one. I got the thermostat, with rubber gasket, the big gasket that seals it all up and also a flat washer came in the package. Can you tell me where this metal washer goes ? Thanks, Tim
The shiny flat washer with the small hole in the middle is for the poppet screw, if needed. It flattens the poppet diaphragm. If just changing the thermostat, just throw it in the tool box. I recommend the "Thermostat Kit" I referenced earlier, change it all out while you are in there. Always test your thermostats, both old and new, on the stove in hot water with a thermometer, looking not only to open near temp - you want ALL THE WAY OPEN. The one I last replaced was not opening all the way.
Isn't 18 ft/lbs the recommended torque for the cylinder cover? The five thermostat cover bolts are 24 ft/lbs according to the Seloc manual. This for my 2002 90 hp 3 cyl but the cylinder cover is identical.
Just doublechecked. Page 4-56 of the Mercury service manual (part# 90-830234R3) says "Thermostat/Poppet Valve Cover Screws - Torque to 18.lb.ft (24.5Nm)"
Thanks, I guess the 90 is different, double checked myself this AM.
I need to install my front cover and want to make sure I’m torquing to spec. 2003 mercury 90 hp 2 stroke. Mine are all common M8 bolts for the cover and therm cover. So is it 24 or 18 ft lbs?
I have to add something else. The diaphragm on my poppet assembly was placed in backwards. It didn't seem to fit right that way and that's why I came back to look at yours. I will not be going back to my last mechanic.
How did you get the thermostat to open at 120 degrees.
I can pnly get pot of water to 100 degrees
its in Farenheit (120 is about 48c)
Hi
Okay thanks
That explains why and doesnt say that well online
Thanks mate
That Helps
Nice video
would a older engine 1985 mercury 2 stroke 90 hp i cant find it the thermosthat
Whats the brass sensor? To the top right of the spark plug, looks like its connected by a thin wire to something
Also known as the "Sender", or "Sending Unit". They send ohms back to the gauge that vary with water temperature, and only work correctly with a paired gauge designed for that range of ohms. If your motor does not have one, there is probably a brass plug in the hole.
could for the love of god someone tell me what the brass fitting above the top spark plug is? i have cooling water spraying from here. have no idea.
It's a temperature sender unit. I have a video on it as well, just search my videos for temperature.
@@striker1211 thank you so much. could i just silicone this off or one way or another block it off its spraying water all in my cowling.
@@striker1211 my thought process is, it wasnt shooting water out of that port before and now it is and im certain it was never plugged. is there a chance i could have a PRV/poppet valve stuck open or a blockage somewhere?
Do you have a good place to find the thermostat gasket (black circular gasket)? I have a thermostat but can't seem to track down the part number online. Accidentally got a thermostat without the gasket. I plan to replace the thermostat and poppet soon.
I have a 98 merc 115 elpto 2 stroke.
I'd recommend getting the serial number of your engine and looking it up in the parts catalog: www.mercurymarine.com/en/us/parts-and-accessories/parts-catalog . The closest thing I could find was part 27-62386 which is available on amazon, but it could vary since I don't have your serial number.
youre supposed to line the groove of the thermostat, inline with the groove of the housing to allow proper waterflow.
What does the poppet valve do I took my thermostats out and BOTH are in the OPEN(HOT) position when COLD I don't know how that could happen I'm soaking them in vinegar.
the poppet valve is part of the cooling system. Its a water regulating system. think about it like this. at low RPM's, or in idle there isn't as much pressure in the cooling system so the poppet valve stays shut. (Garden hose with thumb on the end to increase pressure/distance.) When the outboard is at higher RPM's the impeller is in higher RPM's too, this increases pressure & begins to open the poppet valve. Once enough water is going through the system to keep the engine at proper temp, the poppet valve opens completely. (Thumb off garden hose). Once the poppet valve is completely open it dumps any excess water out of the cooling system as to not over pressures the cooling system. (bypass)
subscribe to us :)
The thermostat regulates water flow at idle (low water pressure). The poppet regulates cooling when the block pressure exceeds 6 psi.
It is important to have a functioning thermostat, if the piston heats up faster than the cylinder wall you can get a cold seize and the motor will need a rebuild. Also, if the poppet is stuck open the water will not be able to build up pressure in the block at low rpm, and you could over heat. Additionally, if the poppet is stuck closed you could over heat at higher rpms since the cooling water is not allowed to circulate from the block.
You scared me with that big torque wrench I just knew there's a snapped bolt or pulled threads coming.
Probably rust because it’s stainless into aluminum. They react for some reason
You people are killing me unless you live in Minnesota and the lake in frozen you don’t need thermostats on a outboard they run cooler and that’s what you want in these old 2 strokes unless yours is computer controlled u don’t need them
I'll leave mine in because I don't want to have to think about water temperature lol. It's like a $20 part.