heres how to break in your engine faster

GoldenMotor.com

masterx1234

New Member
May 7, 2009
51
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grayson Kentucky
What's The Best and quickest Way To Break-In A New Engine ??
The Short Answer: Run it Hard !

Why ??
Nowadays, the piston ring seal is really what the break in process is all about. Contrary to popular belief, piston rings don't seal the combustion pressure by spring tension. Ring tension is necessary only to "scrape" the oil to prevent it from entering the combustion chamber.

If you think about it, the ring exerts maybe 5-10 lbs of spring tension against the cylinder wall ...
How can such a small amount of spring tension seal against thousands of
PSI (Pounds Per Square Inch) of combustion pressure ??
Of course it can't.

How Do Rings Seal Against Tremendous Combustion Pressure ??

From the actual gas pressure itself !! It passes over the top of the ring, and gets behind it to force it outward against the cylinder wall. The problem is that new rings are far from perfect and they must be worn in quite a bit in order to completely seal all the way around the bore. If the gas pressure is strong enough during the engine's first miles of operation (open that throttle !!!), then the entire ring will wear into
the cylinder surface, to seal the combustion pressure as well as possible.


The Problem With "Easy Break In" ...
The honed crosshatch pattern in the cylinder bore acts like a file to allow the rings to wear. The rings quickly wear down the "peaks" of this roughness, regardless of how hard the engine is run.

There's a very small window of opportunity to get the rings to seal really well ... the first 20 miles !!

If the rings aren't forced against the walls soon enough, they'll use up the roughness before they fully seat. Once that happens there is no solution but to re hone the cylinders, install new rings and start over again.

Fortunately, most new sportbike owners can't resist the urge to "open it up" once or twice,
which is why more engines don't have this problem !!

An additional factor that you may not have realized, is that the person at the dealership who set up your bike probably blasted your brand new bike pretty hard on the "test run". So, without realizing it, that adrenaline crazed set - up mechanic actually did you a huge favor !!
 

Shadeslay

New Member
Feb 25, 2009
119
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Arroyo Grande, Ca
From what I've read that's the best method for racing bikes. Reason being they tear them down often and it's too time consuming to break them in the traditional method. I will say also from what I've read. Breaking in motors now doesn't require near the amount of time it did even 10-15 years ago, because of the precision achieved now, older motors required more wear to seat properly. Of course how much precision involved in these HT motors is debatable.

Not saying this method works well or doesn't for HT motors, but the article was targeting well made motors.
 

skinnydog1_2007

New Member
Mar 12, 2009
19
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53
melbourne australia
Does this apply to the 80cc china engines as well. They seem to be quickly built already Ive replaced quite a few bolts the clutch cable snapped engine mount bolts at the rear broke/snapped off ect only had the motor for 2 months. They seem poorly made. I was reasonably gently with it for the first 5 tanks of fuel taking it easy not going over 20klms p/hr or so That was painfull I could have pedaled faster than 20klm. Anyway that's what zbox australia recomends with their engines who I bought it from. At times on the bush tracks could not help my self gave it a real flogging " Gee that was fun" I guess what was said about racing bikes could be true but what do they care if the motor blows up later in the long run they have sponsors to give them a new engine
(STILL CONFUSED)????
 

Bikeguy Joe

Godfather of Motorized Bicycles
Jan 8, 2008
11,837
252
63
up north now
Run in your engine with different throttle settings and amounts, and don't be afraid to let it sing.

Do not, run it too slow with too much of a load on it.
Do not run it down long hills with no throttle, you'll starve it for oil.
Do not use too much oil- I know the "instructions" say 16:1, but that is B.S. 24:1 is good.
Make sure the fuel to air ratio is correct.
 

city of angels

New Member
May 24, 2009
470
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tucson az
i have been using sinthetic oil with my new motor and so far no problems u could buy this oil at the home depot the oil is made by ryobi it the botle say exact mix i was using 20:1 for the first two gallon of gas and now i am using 32:1 and so far no problems
 

Clotho

Member
May 25, 2008
304
2
18
what is the best kind of oil to use for break in?
Anything but synthetic. The reason being is that synthetic oil does offer superior lubrication and this can prevent the rings from achieving a proper seal. After the rings seal synthetic is fine and even desirable.

Here is some information that supports this thread. About 3/4's down the page he says No Synthetic Oil as well.

Break in Secrets

There is actually 2 stages of breaking in a 2 stroke bicycle motor in my opinion. There is the first 40km or so that are crucial. This is where the rings are seated. The other break in point comes many hundreds of kilometers later. At some point you will notice that the engine is running smooth and strong. Stronger than when it was new. This is the second break in point and you want it to happen many hundreds of kilometers later. On my last motor I think I noticed this at about the 700km mark. The longer it takes to reach this point means the longer the engine is likely to run before it will require rebuilding.
 
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xlite

New Member
Jun 18, 2009
735
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ny,ny
I agree synthetic is a mistake for breakin and also bad for storage based on experience with Rotax aircraft engines. My favorite is Walmart outboard oil for everything.

IMO it's better not to baby the engine after the first few miles if you want good performance. I also notice that 2 stage breakin phenomenon.
 

Bikeguy Joe

Godfather of Motorized Bicycles
Jan 8, 2008
11,837
252
63
up north now
DO NOT USE OUTBOARD OIL FOR AN AIR COOLED ENGINE.

Get the all purpose stuff in the lawnmower area if you are uying you oil at Walmart or K-Mart.
 

Shadeslay

New Member
Feb 25, 2009
119
0
0
Arroyo Grande, Ca
Break in Secrets

There is actually 2 stages of breaking in a 2 stroke bicycle motor in my opinion. There is the first 40km or so that are crucial. This is where the rings are seated. The other break in point comes many hundreds of kilometers later. At some point you will notice that the engine is running smooth and strong. Stronger than when it was new. This is the second break in point and you want it to happen many hundreds of kilometers later. On my last motor I think I noticed this at about the 700km mark. The longer it takes to reach this point means the longer the engine is likely to run before it will require rebuilding.

I've been thinking the same way. So I decided to try each method myself, I figure these engines are cheap enough to experiment on. Which is why on my newest engine I'm trying a combo of the break in that thread for the first bit, then vary the throttle like the other method. At 1k miles I'll tear each down too see for myself.
 
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matt167

New Member
May 20, 2009
420
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usa
DO NOT USE OUTBOARD OIL FOR AN AIR COOLED ENGINE.

Get the all purpose stuff in the lawnmower area if you are uying you oil at Walmart or K-Mart.
yanno, I have a new bottle of TCW-3 outboard oil.. I don't really remember why I bought it ( couple years old ), havn't had a 2 stroke boat in years.. anyway, it's supertech brand and on the back of it, it says it can be used with lawnmower type air cooled engines which I know is totally bogus as not only do I know better, spec sheets off the internet say diffrently.. doesn't make sense to put a bogus label on the bottle when it could destroy the engine and that company 'could' have to pay for a replacement
 

xlite

New Member
Jun 18, 2009
735
0
0
ny,ny
yanno, I have a new bottle of TCW-3 outboard oil.. I don't really remember why I bought it ( couple years old ), havn't had a 2 stroke boat in years.. anyway, it's supertech brand and on the back of it, it says it can be used with lawnmower type air cooled engines which I know is totally bogus as not only do I know better, spec sheets off the internet say diffrently.. doesn't make sense to put a bogus label on the bottle when it could destroy the engine and that company 'could' have to pay for a replacement
It will not destroy your engine. I have been using that on 2-sroke bike engines at 50:1 for over 6 years and never had one seize or wear out early. One of my engines has 14k and is just now losing compression.
 

xlite

New Member
Jun 18, 2009
735
0
0
ny,ny
DO NOT USE OUTBOARD OIL FOR AN AIR COOLED ENGINE.
Get the all purpose stuff in the lawnmower area if you are uying you oil at Walmart or K-Mart.

Joe, do you have first hand experience that is true? Mark Smith, top ultralight expert in the US, recommends it for Rotax full size airplane engines and I have been using it and other TCW3 formulations on my bikes and planes for years with excellent results. Is there any credible evidence anywhere that it causes wear or seizure?
 

chrisme

New Member
May 30, 2009
423
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0
Maine
air cooled 2-stroke engine run hotter than water cooled ones. So the outboard oil isn't meant to get as hot and is more efficient at lower temps.
 

Mike Hunt

New Member
Jun 9, 2009
184
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0
Toronto, Ontario
how can i tell if oil is synthetic or not? ive got a bottle of motomaster 2-cycle engine oil sitting in my shed, but it doesn't specify on the bottle if its synthetic or petroleum based.
 

chrisme

New Member
May 30, 2009
423
0
0
Maine
if it doesn't say, it is probably regular. Also, if it doesn't say and it is really old you probably shouldn't use it anyway...
But I always thought 2-stroke oil was all blue... Untill I got some synthetic which is sort of a gold brown colour. Sort of like fresh engine oil.
 

Dan67

New Member
Jun 23, 2009
8
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0
Columbus, Ohio
I have a new build. Gas ratio: 20/1 80cc. It seems to me this sucker gets really hot, really fast, with only a small amount of riding. Is this normal?