Break in of a 2stroke outboard

[nwcove]

Re: Break in of a 2stroke outboard

boater, i think you have the right idea, you did the research, got the opinions, break it in, keep an eye on what the plugs look like (post pics of plug condition....just for other guys/gals to have a benchmark) and your motor should last for many years!

 

[JimS123]

Re: Break in of a 2stroke outboard

Forum gossip and written articles are opinions and only as good as the person who wrote them. Taking advice from someone on the internet is very risky. Listening to the guy at the marina is even worse, because most of them have no practical experience (like running at idle for an hour.....LMAO....boy I'd steer clear of that guy).

The Owner's manual should be the guide. Doesn't matter if it was written 20 years ago. If it came with the motor its what the manufacturere knew best at the time.

 

[aerobat]

Re: Break in of a 2stroke outboard

basicly when you keep clear of the two extremes- one the one hand just WOT it out of the box all the time and on the other hand idle it at the dock for hours when new , your rings will seal properly. just ride it "normal" like said and do not care much attention what seals inside the engine. thats the idea of evinrude etec story- of course also an etec has to break in but the best way to do it is to just treat it like the other time and not to specially avoid high loads and rpms . the engine protects itself by giving more oil for some first hours and etec markets the whole thing as " no break in is necessary"

from the motorcycle scene i also indeed heared about some guys who run their new bikes VERY hard ( as long you can do it at public streets with a big bike...) and they report best results, but i would be careful. jims statedit good- when you follow some internet or marina hints from "experts" and something goes wrong nobody will solve the damage for you.

again- idling it at the dock will create no real pressure at the rings and they tend to polish the cylinder wall instead pushing hard against it to seal . the result is a suboptimal compression and power. you can not invert this when once happend. and the crucial time window is small .

floor the engine whole the time will create much combustion pressure and push the rings hard against the cylinder wall ( which is very good) to let them seal perfectly , but you risk that locally , at the still microskopic rough points of the wall such a heat builds up that the oil film at this location breaks and you scratch the cylinder . the whole idea of a hard break in developed in nowadays since the machining technology is better and the cylinderwall is less rough when new and better heat resistant oils are available. breaking in an engine hard with honing technologies and oils of the 50-60?s would surely be asking for trouble.

when you can make sure that the oil film resists the local heat running an engine hard out of the box might truly be good but it is against the manufacturer recommendation.

most recommend to change loads and rpms without using full load. they do it to keep clear of warranty issues. a lazy broke in engine may not develop its full potential but will keep on run. a hard broke in engine with a sratched cylinderwall may be an warranty issue.

i personally broke every new engine in by giving it hard bursts of power and rpm but kept out from staying at high loads for a longer time -to on the one hand seal the rings and on the other hand avoiding a buildup of hotspots on the rough cylinderwall places. when you think about it its a using the engine at different loads and rpms and that basicly what the manufacturer recommends.

 

[boater1234]

Re: Break in of a 2stroke outboard

Do you think adding a bit more oil then double will give it a better protection on the breakin or it won't matter how much oil you use?Also when you say hard loads do you mean like heavy loads as in weight in the boat or wot all the time.I have a ton of 100%full synthetic tcw3 pennzoil i am going to use after breakin,i wonder since the theory behind synthetic oil is the engine runs cooler with it if it would help with this situation as far as the heat buildup on breakin.I have always been told to never breakin an engine with a synthetic but it almost seems like a myth anymore as so many engine makers are putting synthetics in from the start.

Any thoughts on that aerobat?

I do kinda what you say,i hit the throttle all the way to wot then let off to like 3/4 and vary the rpms up and down.I never hold wot for more then a min or two+i only go to wot a few times the hole time i'm on the lake breaking the engine in.The motor seems like it has some good power to me.It's actually a 9.9hp 2stroke yamaha from the marina and as we all know it's a detuned 15hp.I just went to my marina and got the part installed it needed to get back to a true 15hp,the only difference between the 9.9 and 15 is very little.It's a different reed valve change that sits behind the carb and nothing else.Actually it's the same reed valve that is in the 9.9 but the reed valve is wide open so it can get the full air intake to make that extra 5hp or so.Unbelivable how that little part makes a whale of a difference.Well hope to hear more on the subject.

Also jim i know a ton of marinas know nothing but the marina i go to knows their stuff and has been in business for a long time with the same people and i 100%trust what they say,almost everytime i have a problem or question about a specific outboard they are spot on with the answers.The yamaha tech they have there has been with them for a long time and knows his stuff blindfolded.There about the only marina in the state of fl i would trust to get my stuff done.

 

[boater1234]

Re: Break in of a 2stroke outboard

Anymore help on this last question?

 

[ondarvr]

Re: Break in of a 2stroke outboard

Anymore help on this last question?

Yes, don't over think it, read the manual and follow it somewhat closely...or do whatever you want and report back.

 

[Sea Rider]

Re: Break in of a 2stroke outboard

If you use more oil than recommended 25:1 for break in purposes, the engine will smoke worst than a complete indian tribe and probably will foul plugs faster, stay with recommended break in mixture. Some guys at marinas don't know where they are standing and will have their own personal tech opinion, better is to stay away from them. Some engines updates just need next model carb gasket, cam swap which are the fastest and cheapest to update, other needs complete carb swaps, reed valves, which turns more costly to update. The difference between a 9.9 to same updated 15 is slight more final speed, but better torque for faster out of the hole issues and pushing heavier boats.

Happy Boating

 

[aerobat]

Re: Break in of a 2stroke outboard

Do you think adding a bit more oil then double will give it a better protection on the breakin or it won't matter how much oil you use?Also when you say hard loads do you mean like heavy loads as in weight in the boat or wot all the time.I have a ton of 100%full synthetic tcw3 pennzoil i am going to use after breakin,i wonder since the theory behind synthetic oil is the engine runs cooler with it if it would help with this situation as far as the heat buildup on breakin.I have always been told to never breakin an engine with a synthetic but it almost seems like a myth anymore as so many engine makers are putting synthetics in from the start.

hey !

i would stay away from excessive over-oiling since you just foul the plugs and soot up the engine with carbon. give just the manufacturer break in mixture, not more. also- the "non synthetic" hints are for four strokes and even here its an old myth. like you say most manufactures go for synthetic out of the box and no more oil changes after break in are needed. a two stroke burns the oil so use a good one up from first ride. with "hard load" i mean not the boat weight but the engine load. so... after warm up to operating temperature dont be afraid on a new engine to push the lever full to the wall and let the engine rev up maximum rpms. BUT than after 30 seconds or so back off again and ride with medium speed varying the rpms and load. then you can again WOT it for a minute and then back off again with the lever. when i understand right you did something similar to this on the previous engine and you see the good results on your own.

most manufacturers ( i know fior sure ) do a short run of the engine before delivering and they dont forget to floor it for a short time for initial and very important ring seal. the customers just do not know that their engine already saw some shots of WOT before they get it. but the costs would be too much to fully break it in so you do the rest of the job.

 

[boater1234]

Re: Breakin of a 2stroke outboard

Re: Breakin of a 2stroke outboard

Thanks guys for all the great tips and posts.I think i will just do what i'm doing for at least 2 full tanks of gas which would be 6 gallons total.After the 6gallons i will still do double oil for at least one or 2 more tanks [3 to 6 gallons of gas] but i will do more wot then i'm doing now.After i'm done with all the breaking in and double oil i'm gonna switch to a full 6 gallon gas tank and then use my 100%full tcw3 pennzoil.

The thing that still makes me wonder is they say you can run these motors at a 100:1 oil ratio which is extremely lean.Alot of people think it's a epa thing for cleaner air.I have been told by most people to run it at 50:1.Does anyone know the real truth to this topic.Is it really a epa thing or can you really run these outboards at 100:1 all the timewith never having a problem.The motor won't sit for more then a week or two at the very most and i have heard a ton of people say that is why johnson went from 100:1 back to 50:1 because alot of people would let the motor sit and then when it came time to use it again there wasn't enough oil on start up to lubrcate the engine or something of that nature.That will never be a problem here as we can boat all yr around in fl.This is about the last thing i will need to find out if someone can tell me what the real facts are.I mean it's a big difference from 100:1 to 50:1.I just want to make sure if i go to a 100:1 it will be safe to do.I have heard from some people here that actually having more oil will give you more power.In other words running at 50:1 has more benefits to it then 100:1,is this true?Maybe the middle is good at 75:1 so you can get the best of both worlds.Thanks for any help.This is all i need to know to have peace of mind,i want to make sure that i don't burn this outboard up.

 

[JimS123]

Re: Breakin of a 2stroke outboard

Re: Breakin of a 2stroke outboard

"ton of people say"...."lot of people"...."a guy told me".

All crap.

Follow the owners manual.

The worst mistake I ever made was listening to the Yamaha guru on a forum. His IMHO differed from the owners manual. Nuff said.

 

[boater1234]

Re: Break in of a 2stroke outboard

Well i think i'm gonna run the motor on a 75:1 ratio as most people i have talked to run it at a 50:1 oil ratio.The manual calls for 100:1 which seems way to lean in my opinion and several others i have talked to.So i will just go in the middle at 75:1 to be safe.

 

[JimS123]

Re: Break in of a 2stroke outboard

Well i think i'm gonna run the motor on a 75:1 ratio as most people i have talked to run it at a 50:1 oil ratio.The manual calls for 100:1 which seems way to lean in my opinion and several others i have talked to.So i will just go in the middle at 75:1 to be safe.

That's exactly what I did based on the comments from the Yami "expert" on the Yami forum. When I finally went to 100:1 based on the fact that my dealer chastised me for 75:1, that's when the engine first started running good.

 

[boater1234]

Re: Break in of a 2stroke outboard

So what your saying is your yamaha ran the best on a 100:1 ratio.I wonder why that is.That is weird because i would think all the modern mercs or suzuki's etc 2strokes like 2000 -2006 when they were last made would be also able to run on a 100:1 ratio as they can't be built much different then yamaha.But most of the brands say 50:1 except yamaha,i wonder why?Oh well i am running at 25:1 now on the breakin and it runs great so i can imagine if i ran it on a 100:1 ratio it would run extremely smooth and quiet.

 

[MOETOROLA]

Re: Break in of a 2stroke outboard

I know this is an old thread, but I though you guys might be interested in how they break in 2-stroke aircraft engines. Lots of information bout it on the web. For example one site has a specific thermal break in schedule completed in just over an hour with double oil. Example: 1st thermal cycle, 5min/1500rpm then 5min/1500~2000rpm slowly raising rpm during the 5 min, then 2min idle cool down and then 10 to 15min engine off period. Ill skip to the last thermal cycle number5, 5min/1500rpm then 5min/6000 to full throttle slowly raising rpm during the 5 min, then 2min idle cool down and then your finished. After that fly it like you stole it. After the thermal break in you half the oil mix by half of the recommended mix for 10 gallons. then after that go to normal mix. Totally different break in period then our outboard break in recommendations.