Breaking in a brand new 15-20hp 4stroke

TinBoats.net

Help Support TinBoats.net:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

scoobeb

Well-known member
Joined
Aug 29, 2011
Messages
875
Reaction score
1
I have been researching this for a long time and i was just wondering what people thought of the moto mans way of breaking in a 4stroke engine?It seems to make a ton of sense as when we buy a new car we never take it easy so why go easy on a new outboard.Yes i know we are not going to maintain 6000rpms driving a car like when we run a outboard but to set the rings it makes perfect sense to break it in hard.

One thing i think some people don't realize is the companys put these motors through some harsh tests before even leaving the plant to begin with already and never hurt these outboards.I belive if they were worried about taking it easy in the beginning they would never run up the rpms in the plant but they have to to test them out.I'm sure they run them hard for quite a bit of time also so they are probally in the breakin process already.

Anyone ever try this or even think about trying it?I'm by no means saying it's right it just peaks my interest and wanted to hear if anyone had anything to add to it.It would just seem like you want to condition the motor the way your going to run it which is usually hard most of the time.

Really looking foward to some feedback on this,thanks.
 
Key to breaking in any engine is do not let it idle for the first hour minimum. Best way to break in a 4 stroke is let it idle at 2500 rpm for 30 minute. And no wide open throttle first hour. Hard to do with a boat motor tho.
 
I never said i wouldn't follow the manual,the biggest thing i feel about the manuals though is i belive their so outdated and have never been updated at all.I never said the manuals are not correct but they have been the same for 2strokes and 4stroke as they say do exactly the same for both.A 2stroke and 4stroke yes has rings that need to be seated but the 2 engines are so different thats why i never understood why they shouldn't be broke in different or should they be broke in the same?

Not that it's a big deal but most manuals also say to use whatever brand oil the motor is,like merc oil or yamaha etc....which to me is a marketing thing as you can use any oil you want as long as it's approved for cars you can use it for a 4stroke outboard.I know many people who use nothing but car oil for thir outboards with thousands of hrs and never one oil related issue.Now i have been told that full synthetic oil is not recommended because it causes the outboard to run cooler then like say dino oil and it can never get to full temp operation.Then almost 75%of the people i know that have 4strokes use synthetic so i guess it's just preference.

One is a basically car design engine and the other has been around forever.This has just peaked my interest thats all.If you take time and read what the website says,meaning what motoman says he makes very valid points and makes perfect sense thats all i'm saying.
 
I followed the owners manual when I broke in my 60 merc 2 stroke to the letter. Haven't had any problems from it at all, but I've never had it over 4500 rpms either, just never saw the need to go that fast in my boat. Mfg'rs know what the internals will look like when the break in is done differently than recommended, and may not cover any damage, years ago probably would, now its another whole story imo.
 
I have known a few people that have taken their 2stroke and 4stroke right out of the box and just went hard no breaking it in at all and have never had one issue.Maybe breaking in an outboard is for the manufactures peace of mind like if there is going to be and issue with the motor they figure your going to take it easy in the beginning so limited to no damage would be done if that happens.I have always been told the most important thing on a boat motor is setting the rings right and the way to accomplish that is running it in as hard as possible.

I have actually been told that by a few marinas i have gone to for yrs and their pretty trust worthy people to me.Now please don't take this wrong because i never said it was the right thing to do it's just what i have been told by a few marinas.I bought a brand new 9.8 nissan 2stroke like 13yrs ago when i knew very little about outboards and i just took it out of the box and checked the lower unit oil and followed the double oil breakin instructions but as bugpac said it was to hard to follow the breakin scedule.I just didn't have the patience to do so.I went hard balls to the walls out of the box and still to this day the motor has perfect compression and has never i mean never had one issue,could be luck i guess.

I know a ton of people who have done this and never had a problem so i can't see them all being lucky.I think to set the rings you need to run it hard.They say you need to vary your rpms to break it in right but if we think about this we end up doing that all the time anyway as we have to slow down in no wake zones and usually vary it when were heading to our fishing holes to.At least most people i know do that.So i ask could the breakin of an outboard be over rated?

How can a etec be no breakin but every other motor is that makes no sense to me.I know the computer feeds the outboard a ton of oil so it's getting it's double oil from that but it still has rings right?What makes a etec so different from a say normal 2stroke even know were talking 4strokes.The only different thing i see is that the computer on a etec feeds it the proper oil it needs as with a classic style 2stroke we need to add double oil to our gas tanks.Is the internals on a say 25hp etec so different then say like a 25hp 2stroke yamaha?Now i know the etec is a dfi motor and the computer is more advanced but i'm talking like the internals of the motor that make it go like the rings,pistons etc.....

I'm just curious as this stuff really peaks my interest.Any info would be great,thanks.
 
I've heard of the "balls to the wall" theory for years, and read numerous comments the same as yours, no problems at all. if it works for you, thats all that's important.
 
I may try the balls to the wall method again as i have heard a ton of success with it as you said.Once i get my outboard i will give updates.I'm still debating on the 20hp merc and the 20hp suzuki.It's a tuff decision.It's going on a 1436 lowe jon boat rated for a 20hp.It's a 2003 boat but it is built like a tank.
 

Latest posts

Top