How To Tune Up 4.3 Mercruiser Engine

Learn how to tune up the 4.3 Mercruiser engine in your boat. In this video we show you how to replace the spark plugs, spark plug wires, distributor cap and rotor too!
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[@HomeOwnerRepair]

Buy Tools Needed For The Job
👉Buy 4.3 Mercruiser Tune Up Kit: amzn.to/450iINx
🔧BUY Anti Seize Threat Lubricant: amzn.to/3L9S3WZ
🔧BUY Neiko 3/8 Inch Socket Set On Amazon: amzn.to/3kUuGpN
🔧BUY Ratchet Wrench Set: amzn.to/3mKWIFh

[@bobbreit5244]

I was a marine mechanic 30 years ago and just retired and bought a boat. The 4.3 is a nice system and I appreciate all the heads up on the work I need to do.

[@jacobhurstt651]

Thank you for this video

[@HomeOwnerRepair]

Thanks for watching!

[@gutterclear1051]

Thanks for posting this i am finally starting to do my own work ! Just noticed yesterday while on water one manifold (port) is running cooler to the touch than the other ...on plane temps are great ...come back down to idle and they climb again a bit .I am thinking the impeller is shot or I have a block in the manifold .
Anyway the tune up videos will help my out alot as i have the same motor !

[@HomeOwnerRepair]

This happened to me last year. It is recommended that the impeller be replaced every 2-3 years from what I was told. I had an issue when I was moving the engine was cool and when I was at idle it would heat up. This is a classic bad impeller symptom. I had it replaced last year and now it runs awesome. Nice and cool at idle and at speed. Hope this helps you out.

[@AchikSarih]

Merci beaucoup ❤❤❤❤❤❤

[@HomeOwnerRepair]

Thanks for watching.

[@gibbsremovalsltd6590]

Great video thank you, I will be doing this. I have the same problems with heating up on idle but when running temp is fine. I did notice as you look at the engine on the right hand side is a cap with fluid in? Mine seems very low what is the fluid that should be in there? I know it’s not oil but don’t know what it is?

[@HomeOwnerRepair]

I believe you are referring to the power steering fluid. It's the black bottle on right with the pulley. If you're running hot on idle it may be the impeller that needs to be replaced. Same happened to mine.

[@andrewtobias6207]

I have the same engine setup and for the life of me I can't find out where to put the outdrive reservoir. Can you send some images or post a video of how yours is mounted? Thanks!

[@justinmahley3872]

I have the exact same boat. My motor runs great when throttled up but it keeps stalling out at idle. Got any tips

[@kylehassell6476]

Great video! Pulling the engine to replace a broken engine coupler and will be changing starter, plugs and plug wire. Mine is a 94 4.3 Mercruiser. Is AC Delco recommended by factory? Or can I use a different brand?

[@HomeOwnerRepair]

The AC Delco is a good starter, if there is a different brand that fits your application you should be fine to use it as well.

[@AchikSarih]

Merci beaucoup ❤❤❤❤❤

[@HomeOwnerRepair]

Thanks for watching.

[@HomeOwnerRepair]

Thanks for watching.

[@JamesConnelly-lj2gj]

I just wanna tell me where the black wire comes off the distributor does it go to the kill switch on the port bank heat stranger

[@HomeOwnerRepair]

I currently do not have a wire diagram that shows it's position.

[@traviswagner9822]

Thanks for not making complicated. What year is your engine

[@HomeOwnerRepair]

Mine is a 1989

[@troyniehus8497]

Is your motor a cold blooded thing to start? I replaced plugs, wires, distributor cap and rotor still a cold blooded thing. Also just put a new prop on as old one was chewed and broke, how fast can you go top speed?

[@troyniehus8497]

​@@HomeOwnerRepairalso I have 89 crestliner phantom with the 4.3 mercruiser alpha 1 also.

[@gogreen1963]

Thanks for the great video. Hoping to finish by this evening.

[@STAT303954]

Hey I have the same engine as you.... can you do a video on adjusting the valves?

[@HomeOwnerRepair]

I will keep this request in mind in the even that I need to perform this repair.

[@gibbsremovalsltd6590]

Sorry lol my engine runs at just over 4rpm at the moment but goes up to 6rpm is there a way to get it up to 5/6rpm for more speed

[@HomeOwnerRepair]

There might be a carburetor or linkage adjustment that may need to be done if the idle is too low.

[@colenoble3512]

Can you make a video on changing the thermostat

[@HomeOwnerRepair]

I'll keep this in mind for a future video. Hope this video helped you out with your 4.3 Mercruiser.

[@floridagirl386]

I cant even get mine to start. Ive found a wire that goes onto the starter, looks corroded? Can you verify via email? Im trying to not get scammed by the mechanic & doit myself

[@HomeOwnerRepair]

If you found a corroded wire you may want to clean up the connections at both ends.

[@floridagirl386]

@@HomeOwnerRepair ok it has a glass fuse? Inside of it

[@williamgares06]

​@floridagirlxoxo5225 that's the 90 amp fuseable link. Just replace it.

[@floridagirl386]

I got my boat to start & run!!!! Never got scammed by any mechanic & am so thankful for youtube!! I've done the carb, lower shift cable, pulled the stern & then lower unit a couple times, drain all liquids & she's been on the water many times!!! Waiting for my starter to get here (have to cross stud start it lately lol) but eventually I will rebuild the entire engine when I'm comfortable. What a fun thing to learn. Trial & error. . But mostly fun! Thankful for youtube & men. Mostly men lol😂😂❤

[@user-nd6ub4zz6e]

What happens if you mix up the wires

[@nicholasm2239]

The wrong cylinder will fire at the wrong time, your valves might not be open, you're getting ignition not at the right time of the cylinder stroke. Basically it's really bad on many levels. Go read about how a 4 stroke engine works.