Mercruiser 4.3 LX V6 Winterization

[@ShaunPaget]

1st time boat owner going to winterize this week. Best most to the point explanation I found. Thank you.

[@Schneids15]

No problem. Thanks Shaun.

[@fyrftr422]

Excellent video, short and precise! My goto to refresh memory every year. I just wish I had your room beside my engine. 😂

[@Schneids15]

Haha thank you! Yes exactly why I chose this boat to film. Most are not nice like this to work on.

[@ryanlee7895]

I watch this video every October thank you so much

[@DavidLavallee-lu6iy]

Me too

[@mattvest6095]

Thanks so much for this video! Just got my boat this season, and it ran great so I want to make sure I get it properly winterized. It was almost impossible to get to the port-side engine drain plug because my engine has seats on both sides. Your video helped me to locate that plug and make sure that I got everything properly drained. Thanks again!

[@elgol71]

THANKS you just saved me a $150 and a two weeks waiting list on the local shop , my 4.3 is identical to the one on the video really easy and well explained . thanks again..

[@Schneids15]

Glad i could help. They are very very simple

[@denniservin2218]

I loved this video, I have the same '96 4.3 LX, but in my 22 years of ownership, I've never had the hoses off. After I loosened the 1st 3 hose clamps, those hoses remained solidly, stubbornly, like glued on. So, I resorted to my usual process of pouring 4 gallons of RV antifreeze into a funnel to a garden hose to the clamshell flush muff on the intake to the sterndrive, while the engine is running. Not elegant, probably not as thorough, but it works.

[@Schneids15]

That works. Definitely not as thorough and does not remove the rust from the block but yes it does get the job done.

[@daddio3190]

Great video. Straight to the point....I think i have a problem though, water initially came out of the block plugs but antifreeze never did. And i put two jugs in it. Seemed to hold the majority, a little came outta the disconnected hoses. Am i screwed? 🤷

[@tmiii3]

Thanks again. Used as a refresher. I noticed I have these spring loaded ball plugs at top two thermostat housing hoses.( part of thermostat Maybe?) They are very rusted can I discard them as you don’t have in yours. Can’t figure out how to post a photo for your reference. Thanks for the help!

[@tayloreke]

Added to my saved videos for next year, just spent 350 bucks to have this done. I could have done this.

[@larrywalden626]

So have you saved money this year and done it yourself?

[@onestallfab]

Great video thanks. Very helpful as I bought a boat late season and I’m scrambling to winterize.

[@Schneids15]

Glad i can help. They are very straight forward.

[@frankletizia7835]

I going through now . Did your boat freeze or no ? I just bought 1 now got do it.

[@onestallfab]

No, we have not got that cold yet. Sure have to stand on your head to do mine!

[@Schneids15]

There is s select few that i can film. Most are head standing fun.

[@tmartin1167]

I did the muff antifreeze fill. Should I drain the fluid from exhaust and block? I see some people leave the antifreeze and some drain after. Thanks

[@Luigi-pk8mk]

On an I/O with the impeller in the drive I would put the drive all the way down, and disconnect the raw water intake line at the thermostat housing. Point it down in the bilge to drain. Then fill it with -100 AF till it comes out the drive water intakes. You can also just bump it over with the starter just a bit to get the AF fully in the impeller. Reconnect the hose. With the drain plugs I like to coat the threads of the metal ones in OMC gasket sealer or Permatex aviation and put them back in so they don't get lost. I had a plug leak just slightly on my OMC Cobra 4.3 and it leaked salt water RIGHT on the starter solenoid. Made it a rusted mess because the manifold drain was right over the solenoid.

[@Future_memory]

Once you flush with antifreeze and put hoses back on, do you refill with antifreeze or leave it dry ?

[@Schneids15]

I leave them dry.

[@Future_memory]

@@Schneids15 good idea !

[@johnmatthews1634]

Agree on the great video comment . My 1st question is around the type of antifreeze and where to purchase in Ontario Canada. Thank very much. 2nd question, Have you heard of running the engine in a drum with appropriate amount of antifreeze. Pro or con? Thank you

[@Schneids15]

Hey John, running in a barrel or on muffs with antifreeze can be done. However if you don’t want to worry do it this way. As far as antifreeze home hardware, Canadian tire etc is all fine. Some will say for plastic pipes only etc. Don’t worry about that. The system runs dry itself but we dump the antifreeze in to be sure there is no water in it.

[@brainbuster3089]

If you want to put some extra time in, you can fog the engine as well as drain/replace that lower unit oil. I like to hit the outside of the engine with a little wd40. That will keep built up moisture in the engine compartment from developing mold on the engine. Don't have to douse it, just enough to coat.

[@Schneids15]

Yes all good idea’s. We always Fog, gear oil, stabilize disconnect batteries etc. I like the WD40 idea. Also a good idea is to prop open the engine hatch for storage to let it breathe.

[@jondudas2349]

awesome video thank you. first timer here. question, am i just pouring the antifreeze through all the lines as you did and leaving the drain plugs out and the hoses unattached? i dont pour anything in there after all the water has drained out and it is showing antifreeze and leave it in there and reattach the hoses? so more or less i am just flushing the hoses/cooler/lines ?

[@Schneids15]

Yes drain everything and the antifreeze is just a flush to verify everything has drained out.

[@svenlindahl5607]

Very excellent video. Thanks for putting it together

[@buster3108]

Did you have to put the plugs back and the hoses back on the manifold and fill it full of antifreeze for the winter or just run flush it and leave it and not put nothing back together to store for the winter thanks

[@Luigi-pk8mk]

PS if you have a newer Vortec V6 (intake has 8 bolts instead of 12) there is a drain plug on the front face of the intake manifold, left side as you fact it, will be behind the serpentine belt.

[@tyler2011oc]

Older video but helpful. Do you close everything up and fill the engine with antifreeze or is flushing the engine and draining the antifreeze enough?

[@abwildoutdoors]

So If I turn it over - a burp!, should I put a little rv antifreeze then burp it; to get some antifreeze in the lines and impeller?

[@johnman9898]

What about fogging the carb, treating any fuel in the tank and the out drive gear oil?

[@shortwavesurfer7222]

What about fogging? Oil Change recommendation? Stern drive oil change?

[@therighteouscapitalists8821]

Thanks for this. It was a huge help in the fall as it was my first season with a fairly modern boat for which I can find videos like this (I previously had a 1970 I/O Cobra). Now it is time to put her back in the water. Do you have a video for that or is it as easy as putting all the hoses back, putting her in the water, and turning the key? Thank you!

[@strada21_]

Hello great video !ok I have a question,, is it needed to winterize in arizona where it doesn't get minus degrees of cold ??

[@Schneids15]

As long as your climate is not going to freeze there is no reason to drain it.

[@davidqi8073]

some questions after watching: you just need use the coolant to flush the hose, and don't need to fill is up. right? When you drain the water and flush, how did you dry you boat after that? does the water out from the drain hole? Thanks

[@Schneids15]

Hey! Yes coolant is just a precaution as a flush to be sure the engine is drained. It will run out the plug yes.

[@davidqi8073]

Thanks for your reply. Really help me as a new boat owner

[@rev.jimwalton9383]

I really appreciate your video...awesome job. Just curious though...some guys talks about putting antifreeze in for the winter...if you do, you use just standard antifreeze (like auto)....or do you just leave everything open as some guys also say "air doesn't freeze"? Thanks

[@Schneids15]

Hey, so use RV plumbing antifreeze. Non toxic. Also using this method technically you need no antifreeze. The antifreeze is just a visual aid that the water has gone through the system.

[@leonelfrydman5422]

Thank you sooo Mach. Can I use windshield water?

[@Schneids15]

Never thought of that. Can’t see why not.

[@leonelfrydman5422]

Or antifreeze from radiator?

[@Schneids15]

I would not recommend that. Don’t do that. Horrible for the environment. Just get some plumbing antifreeze.

[@aleksandarpopovic7090]

I really appreciate your time explaining it.

[@Schneids15]

It was worth it just for your comment. Thanks Aleksander.

[@aleksandarpopovic7090]

@@Schneids15 i did today 4.3 mercruiser winterizing and i am scared that it is not done properly as i used camco canister and run fresh water up until termostat opened and then switched to the rv -50 antifreeze. Waited up until maybe 4 gallons of antifreeze went through and then i did fogging. I did open 4 spots and pink water went through kind of want to do it again i will put white plate to make sure is pink once it comes out. 40$ extra dollars for antifreeze but i want to repeat the process and will Fogg it again. Fuel stabilizer is in it and 75% of fuel in the tank.

[@Schneids15]

This is why i pull the hoses then put the antifreeze through. Those camco winterizers can cause big problems.

[@aleksandarpopovic7090]

@@Schneids15 totally i spent 100$ for the kit and antifreeze and then realized that i have water then today i went again and bought expensive one without alcohol and put 5 gallons and did exactly what they said and once i opened the plugs it was water so i drained the system and put 2 gallons of antifreeze through all the hose i saw like alllll. Now i see pink if I failed as i am doing it first time totally accepting my fail did it the best to my knowledge. If the block is ok in the spring i am certified marine mechanic:)

[@salvatorezarrelli625]

How did you get the antifreeze past the thermostat to clear all the water out of the block?

[@lifeofbrian7994]

excellent video. Simple and all you have to do.

[@robertrussell6350]

I have a question so the 4 hoses in the front the 2 top manifold and then you said the bottom that goes to the water pump do you pour water in there before you disconnect it and put it in the top?

[@erikhamilton4866]

You leave the antifreeze in the block and risers during winter right?

[@JohnHoppenstand]

Do you close the plugs back off and then fill it with coolant??

[@Schneids15]

No I simply give it a little slosh so I can see the coolant come out the plugs to verify no blockages. The system stays empty and dry. “Air doesn’t freeze”

[@manuelpalinckx245]

Thx, I'm a newbe and this video was great. real easy to do

[@TheBojaboja]

Great video, two questions: Do you run the engine for awhile to make sure thermostat is open prior to doing this, and how much antifreeze do you use for this process, 2 jugs or ?

[@Schneids15]

Hey Jared. One jug. No need to run the engine and open thermostat as you are pouring the fluid around it. Does not matter if open or closed

[@TheBojaboja]

@@Schneids15 thanks for the reply!

[@robertrussell6350]

@@Schneids15 i have a question for you buddy please when you can

[@useldave6868]

Great video!!! You saved me 300 bucks

[@matthewgolz6268]

Best video yet , thanks.

[@skipwangner3149]

water pump is not in the back its in the front, does it need attention as well?

[@Schneids15]

Water circulating pump is in the front correct. Water impeller pump is in the drive.

[@druschli9547]

Question: on the right side of the engine, there is a container behind the pulley. What kind of oil needs to be refilled there?

[@Schneids15]

That sounds like your power steering pump. ATF is what they come with from factory.

[@druschli9547]

@@Schneids15 thank you for the answer

[@paulhaines5755]

Nicely done! I have same engine. I do it pretty much the same way. I consider it thorough. Never had an issue in 20+ years. I also like to spray my hoses with WD40 before I put them back on. Skipped it one year and hoses were harder to get off (or so I thought) - maybe just the placebo effect! What is your opinion on these antifreeze tanks that you hook up in-line with your ear muffs? I bought one but I hesitate to use it. I think it'll be great for my wave runners but I hesitate on the boat.

[@Schneids15]

Great idea with wd40. You know what the ear muffs do work however i would not sleep for the whole winter worrying about if i did my boat that way. Drain it the way you are used to. Your block will not freeze then. You have a good method. Josh

[@itsme_Willow]

Third time watching. Thanks again.

[@Schneids15]

Hey thank you! I am glad I am helping so many people😃

[@KevinLynch-p1t]

How do you change an impellor in a 4.3lx mercuriser

[@larrycottle396]

Rv / marine antifreeze is only used for the fresh water (drinking water) not for engine There is no corrosion protection with rv / marine antifreeze

[@anthonymurphy1624]

Thinking about buying a 2000 trophy boat with a 4.3 mercuicer, 21 ft walk around, the boat weights around 3000 pounds with fuel, please share your thoughts, ease of maintainence, horse power for a boat that size, is a good engine,

[@Schneids15]

A 4.3 will have no problem with that boat. On the mid 2000 models they had some exhaust manifold issues but that boat should be pre that for sure. That being said the exhaust manifolds would have been replaced by now anyways likely... great motors. Very reliable. I have some with over 2000 hours on them. Many from the 1980s still running excellent still. You won’t win any speed records on top end but you should see high 30s in the mph range and it will pop out of the hole just fine

[@anthonymurphy1624]

@@Schneids15 great info. Your the best

[@markgamble8377]

Great.have same engine.this year be my first time winterization.

[@dmudder5529]

Thanks for video, just got same engine. Rv antifreeze vs auto type? What about engine fogging, or do you have a different video.

[@Schneids15]

Yes rv because it is non toxic. Engine has glycol in it, deadly stuff. Yes fog it. Pull the spark arrester( air cleaner) and fog through the carb.

[@LevRage]

Great video...Great Job! Did you remember to throw some antifreeze down the out drive hose? I usually do that until it starts running out of it.

[@Schneids15]

Yes you could do that for sure. I never have put any down the hose. It’s not a bad idea but I have never had one issue in 10 years doing it without.

[@davidqi8073]

Why the thermostat hose inside has springs and my left side manifold hose has a ball size plugs? Thanks

[@Schneids15]

Springs are to form the hose and prevent it from collapsing. If talking the balls that are spring loaded going to manifolds that is so exhaust gas does not push in and go into your cooling system. Only water can go out

[@tspecht610]

Hi. Any chance you can tell me what the propeller size is on this? I have a 1993 Maxum 1800 sr that has the 4.3 that looks identical to this engine so I was guessing your propeller would be the same. I bought a boat that had the propeller all chewed up so I wanted to purchase the correct size and pitch. Thanks.

[@Schneids15]

Hey. I can’t guarantee size because every boat is different. Look on the sides of the prop between the blades or close to the hub on each end and it should show some numbers. You will need to find the pitch and the diameter. It will likely be around a 14 1/4 diameter and a 19P for pitch

[@targabill]

I do it the same except I like to crack open the engine and manifold petcocks and let a little pink out and leave most of the antifreeze in there as it has anti-RUST properties in the antifreeze...

[@brendonhenderson4468]

There are only the 2 actual drain plugs on this one correct?

[@Schneids15]

2 on block, 2 hoses or plugs on the manifolds

[@scotthorman7188]

Great video! It helped me find the two engine block plugs I was missing. Do you winterize the outdrive at all?

[@Schneids15]

Make sure there is no water in the gear oil. I drain and re fill every fall.

[@scotthorman7188]

@@Schneids15 Okay, I'll do so. Thanks!

[@waynebassett8362]

My motor is squealing I have a merc. 4.3. I'm sure it's the belts can you point me in the right direction it's my 1st boat. And I'm clueless

[@Dmski]

Do you know where I can find the owners manual for this engine? Or do you know what fluid to put in that reservoir with the big red sticker "See Owner's Manual" in your thumbnail?

[@d.francis3437]

Any tips for getting the power steering cooler hose off? Mine won’t budge.

[@Schneids15]

Try a flat head screw driver. Sometimes twisting the hose and prying on far end with flat head screwdriver will crack it loose.

[@d.francis3437]

Thanks for the quick response. If I can’t get it off, can I take off the hose at the thermostat and pour antifreeze in it and it will go out the back of the boat?

[@srwven]

Another option if you have mufflers is to warm the engine up, warm hoses usually come off a little easier. Also, lightly use a pair of pliers around the hose where the bracket was and twist back and forth a little. Key word gently as you don't want to damage the rubber. I have done this on numerous auto hoses with success every time.

[@drcoffee5588]

(A little late, but for future visitors) Use channel lock pliers, grip the hose on the nipple and rotate the hose on the nipple. That breaks the seal without damaging the hose. Then you can pull it off.

[@rebeccawilhelm5303]

Thanks for sharing a good video! I winterized my boat similar to how you have some months ago but just realized that I forgot to fog the engine. I really hope this isn’t too important. It’s the first time I winterize myself and I assume it has been managed properly in the past by the previous owners. Do you think the engine is damaged now?

[@Schneids15]

You will be just fine. There is many engines that do not ever get fogged in there whole life and are all fine.

[@rebeccawilhelm5303]

Appreciate your quick reply! (Y)

[@pennewell96]

Fogging isn’t really something you have to do but it doesn’t hurt

[@briangobat6608]

Show me how to change a starter on a Mercruiser 4.3 V6 Alpha One. 1990 Bayliner please

[@helenasantos6796]

Thanks for the video. But its a 205 hp or 190hp??

[@Schneids15]

Unsure what it is. All 4.3 gm are the same though. The HP differences don’t change the winterization process.

[@kacjames]

4.3 LX is 205 and 4.3 195

[@paullota7129]

do you run up your engine or do you do it while engine is cold ??

[@Schneids15]

Engine is fine cold with this method.

[@flak9]

Have you ever had to replace a starter on these? I've got the same engine. Trying to determine the best way to get the starter off.

[@Schneids15]

Either 9/16” or 1/2” wrench. They are a pain depending on the boat. Have to have lots of patience and slowly turn wrench by quarter turn each time. Can be a very frustrating job.

[@leonardotherapydog7677]

I know I'm late with this reply but I replaced my starter last year. Totally sucked! Horrible place in the boat. Must have taken me 4 hours of swearing and scraping my arms up hanging upside down to get at the screws. But I got it done and the boat runs great now. Great video! Are there only 3 drain plugs on this motor? I can't find any more.

[@andresvelez5806]

Hi, i have the same engine but I'm having trouble trying to get it started. It only turns on when was full throttle. When i go back to neutral it turns off. Have you ever had this problem? Thanks

[@Schneids15]

Hey Andres, yes i have. It sounds like the engine is flooded. It could be a sticking carburetor needle valve. Will it ever run normal? Black smoke?

[@andresvelez5806]

@@Schneids15 yes the engine runs. After a while on i get black smoke. So i turned it off.

[@Schneids15]

The black smoke is just your engine running rich. Take your “ air cleaner” off the carburetor and see if your choke is sticking. The “butterfly” flapper on the intake should be straight up and down once warm. If the choke is stuck it could be running the engine too rich and causing this.

[@andresvelez5806]

@@Schneids15 the butterfly flapper is the ways you said.

[@Schneids15]

I would assume you need to get your carburetor rebuilt. It could be your needle and seat not sealing properly and flooding out the engine.

[@david-m-creations799]

Good job Louis..

[@chrishatton9235]

Please keep making videos

[@techwile-fotografiaslubnam3026]

Thanks a lot! 👍👍

[@dougprice1573]

Curious if after putting the plugs back in and the power steering hose back on if you dump in some RV antifreeze and leave it in?

[@Schneids15]

Hey Doug, i leave all plugs out and hoses off all winter. I reconnect in the spring. However you could re connect them and leave the system dry for the winter. Lot’s of people have had that rv antifreeze actually freeze and that is why we leave them empty.

[@drcoffee5588]

I see videos of the AF freezing, but I believe it does not expand as water does, so its actually safe to leave in. It can help stop rust over the winter.

[@frankletizia7835]

I have power steering. I did not see the hose to it were you said drain it. It is 4.3. Lx

[@Schneids15]

There is no cooler? Follow your power steering cooler lines back to the motor. It is rare to not have a cooler.

[@kristoffscuba5466]

Great video and I have used it to winterise my 4.3 for two winters now with no problems. I have one question that I wondered if you could answer, by pouring the antifrezee into the hose like you do at 3min31 in the video, are you relying on the engine being warm and the thermostat being open to allow that coolant into the block? I've never been sure if that is the case, and to be sure I pour coolant in my engine like you do there, but I also put that hose back on in its normal postion and pour coolant down it so it goes down to where the water pump is at the botom of the block. Just wondered if the way you do it, the engine needs to be at full operating temp to ensure coolant enters the block?

[@mikeboston421]

when you pour af into the big hose in normal position it goes into the block where you want it to go, if you pour in the top with hose flipped all it does is go through into and through the intake hose and transmission cooler, kinda useless, so keep doing the af into hose in reg position if you want to get antifreeze ie af through the block

[@evanbushong4291]

Bro is the antifreeze necessary?

[@Schneids15]

It is just a precaution.

[@markholterman6108]

So you are only flushing with antifreeze, not actually leaving it in?

[@Schneids15]

Correct. The Antifreeze is just a precaution. A lot of people just drain them and leave them. But the antifreeze gives you more certainty.

[@jleongrae6354]

wow great video

[@OscarHernandez-vn4ek]

Great video, thank you sir.

[@Schneids15]

Thank you. More to come soon for summerization.

[@1957kwick]

So you just leave all the stuff disconnected until you’re ready to use the boat again or what

[@Schneids15]

Yep

[@larrywalden626]

@@Schneids15 is there any reason why you can’t put in all plugs and fill the areas with pink antifreeze, put hoses all back on and leave it in there all winter?

[@Schneids15]

No reason you can’t. I was always taught air doesn’t freeze and leave them dry. There had been multiple occasions of pink antifreeze actually freezing according to what i was taught in school.

[@ecvtroy]

Appreciate the video. Nice to see it done with my exact motor. Just one question, do you leave the plugs out and the hoses disconnected all winter or do you put it back together?

[@MoJoTec67]

Also wondering this same thing

[@carllange3432]

put it back together. especially if you have brass plugs in the cast iron block. being exposed to the air the threads in the block will rust away over time. then you will have to oversize and rethread the drain hole.( a real pain in the ass in most applications i've seen). better yet, while you still have good theads in the block locktite 1/4 in x 1/8 in reducers (brass) into block then get 1/8 in brass plugs for the brass reducers tread rusting away problem gone!

[@kristoffscuba5466]

I spray the threads in the manifold and block with wd40 or a light oil to stop the air corroding them, and leave the plugs out. Two reasons. 1, you never know if some water might want to come out via condensation (unlikely but can't hurt to give it a way out), and 2, if you put the plugs back in whist the engine is warm, when it cools you might have one hell of a job getting them out again as those plasitc ears on them snap relatively easy. Better to leave it until you are ready to put the boat back on the water and put the plugs back in hand tight whilst the engine is cold. You know then that they have sealed well and you know you can get them out again.

[@WrstlrZ28]

This is very helpful for the motor but I have one question. Do I need to drain the outdrive of any antifreeze or do they drain themselves in the down position? I have a 1986 Four Winns Santara 215 with this 4.3 LX in it.

[@Schneids15]

No you do not. The line that you pull off on the power steering cooler is the one that comes from the drive and will drain back itself. I usually give the motor a tiny 1 second crank on the starter to give the impeller a slight turn so it will drain water that is possibly caught between impeller fins. Not required though.

[@WrstlrZ28]

@@Schneids15 Was not expecting such a quick response. You are the man! I just bought my first boat from my father in law. He's having a mechanic winterize his new boat for $300. I would like to do it myself and save some $$$! I live in Indiana and we are expecting overnight temps to fall below freezing, so I have to get this done tonight. Hoping everything goes as smooth as this video!

[@Schneids15]

It very well should. If not shoot me a comment. Have a small flathead or pick because the lines will need pryed off most likely. Be sure to physically see pink coming out the holes. Be sure to poke the holes that water comes out as it will be rusty likely. Indiana, right on. I have a couple buddies near Indy.

[@AngelSanchez-wv5cq]

@@WrstlrZ28 dou need to put the plugs and then fill it with antifreeze

[@stephengeronimo3110]

don't forget to fog the carb

[@larrycottle396]

Never use every antifreeze also use automotive antifreese

[@danstonge91]

You forgot to drain the intake manifold

[@Schneids15]

How do you drain a Intake manifold?

[@krisnolasco]

Greast

[@marchallaert7372]

Great tutorial. Thank you!