Updated: Dec 17, 2019
For those of you who don’t know me or my history, my name is Steen. I grew up in Northern New York Approximately 7 miles from the Canadian border in a town called Malone. As you can imagine there's not exactly that much going on up there. To fill my boredom in as a child my parents had purchased me a Suzuki LT 50. I rode this quad until the wheels fell off. My mother has always been a huge influence to me, owning and riding many motorcycles since I was born. My mom had owned a Sachs p-1 from when she was young. This moped made its way into my life after unearthing it in our garage. This is the first bike that I learned how to clean a carburetor on. This moped also provided a platform for me to learn the basics of mixing gas and general motorcycle maintenance, to keep it rolling. When this moped was the difference of drooling on a hot summer window versus having fun, I was sure to do everything in my power to keep it running.
From my moped days I graduated into a Dt-80 a Yamaha enduro, Suzuki lt-125 quad, into a Yamaha TW200, then a DR350. At this point things started to get pretty serious. I got my motorcycle licence the day after my auto license, and started racing motocross. From my extensive history of owning bikes you could say I learned a thing or two but nothing compared to what was to come. My first motocross bike was a 99 KTM 125SX. Needing an entire rebuild upon purchase, this is where I first experienced the inside workings of a motor, and how meticulous one must be when building a high performance engine. After building the motor with the assistance of my best friend who happened to be a professional tech, I headed into the world of engine break-ins. Break-ins are like the oil talk of the motorcycle industry. Highly controversial and truly one of the most prized dead horses of the industry. The reason I provided my moto history is the information I am about to present you with will go against the grain of most everything you’ve ever been told. What makes it even more controversial is it’s coming from a woman. However, a woman who has logged well over 148,000 documented miles on two wheels and has performed more than 239 engine rebuilds. Ranging from highly modified Honda XRF/CRF 50s to Honda CRF450s which is the bike that ended my racing career and has left me here, 8 years later sharing my knowledge through blogs, while icing my knee from my second knee reconstruction surgery. TL;DR Quit pussy footing around with your break ins. Ride it like you stole it.
This article is for FOUR STROKE APPLICATION ONLY, if you have found a similar bomb proof method for two stroke application I would be extremely interested.
Being a woman of urgency I was always a bit in a rush and was always looking for the fastest way of getting back to riding. This has not always benefited me, but when it came to breaking in a motorcycle it certainly did! This method was presented to me early in my career and I have NEVER had an issue with a motor failure to date. Piston ring seal is what this is all about. Most individuals think that the spring tension in the rings is what scrapes the cylinders wall of oil and seals the combustion chamber from contaminating the bottom end lubricants. However if you've ever done a top end rebuild with a upside down ring and you’re lucky enough to have it start and run, you’ll see that spring tension simply is not enough to scrape the oil from the sides. Your bike will be billowing smoke and you’ll wonder if they sent you the right over sized piston kit!
So how do the rings seal? As you may know rings have a up and down. Up side often times has a small taper from the outside of the ring towards the center. As the act of combustion happens thousands of PSI (Pounds per square inch) forces its way down to try and make its way past the ring. As it does this the taper in the ring acts as a wedge and applies this extreme force to into outward pressure on the cylinder wall wiping the oil from the walls and sealing the combustion chamber. If you were to examine a piston ring in a exploded view or even enlarged 100’s of times you’d see that the ring is far from being concentric, and has many imperfections. This is where cross-hatching of the cylinder walls comes into play! The cross hatching wears away at the rings during the usage of the motor to form a perfect seal and happy “mating” between cylinder wall and piston. Now this cross hatching is only temporary, lasting approximately 20 miles from it’s first start. If the rings aren’t forced against the wall to use the abrasive properties the cross hatching the rings remain their lumpy self. Once this happens there is no solution but to replace the rings and re-hone the cylinder to properly force the rings into the cross hatching with some WOT!! (Wide Open Throttle)
HOWEVER, Not just WOT will make a proper break happen. Deceleration of the motor creates a vacuum under closed throttle conditions. This vacuum pulls oil and metal shavings that are left behind during the break in. During the closed throttle position, particles suspended in the oil blow out the exhaust , rather than accumulating in the ring grooves between piston and rings, keeping rings from wearing too quickly. You may notice that the engine will puff smoke during closed throttle position. Unlike valve guide leakage which is normally the culprit of this style of oil usage, this will happen only for the first few times. Oil puffs will settle down once the rings have completely established a proper seal between wall and cylinder. So easy there backyard Jerry! This isn’t something you want to be performing in your garage! Settle down and read on! Since most individuals don’t own a dyno nor plan on owning one, I’ll describe the proper break in for the street application. FIRST THINGS FIRST WARM THE DAMN ENGINE UP!!!! Just in case you missed it WARM UP YOUR ENGINE! Wind resistance is a great way to load the motor up. This wind resistance is also very effective in cooling the motor, eliminating “cool down” periods, that most “break-in” sequences call for. Our main goal here is to load the engine in 2nd-3rd-4th gears. The proper way to load the motor is to do short burst of heavy accel and decel. You don’t need to be going 120 mph for this to happen but it might be easiest to perform on back roads. This way you don’t have to worry about traffic following too closely with your erratic speed changes, or stop and go traffic preventing you from properly heavily loading the engine. Another thing to be aware of is riding on the highway. Once you’re at a cruising speed you’re light on the throttle and not properly loading the motor. This break-in shenanigans should be constantly practiced for the first 200 miles. Keep in mind this is not a nut-flex fest of rev limiter bouncing and super high RPMs. This is a conscious active effort to keep the engine loaded under continuous accel and decel. The break in process generates plenty of heat as you could imagine. Metal on metal grinding on itself creates a home among each other. That’s why we want to avoid ultra high revs. High RPMs = High Heat Now let's talk about some of the variables.
Oil - Avoid synthetics for break in!
Hop off your “best oil to use” soap box. In this situation we simply don’t give a hoot how great synthetics have become or if your Uncle Doug chugs a quart for holiday dinner tricks... Conventional oil works just fine and that's what we will be using for this application. Synthetic oils contain polymers to prevent wear and will actually fill in little tiny cross hatches and scratches preventing a proper break in from happening. How do I know this? If you put a synthetic in an oil that is not approved for motorcycles you will find that your wet clutch will “fill in” with these polymers. Thus preventing the abrasive properties of the clutch from grabbing and making the bike move. Some will argue the opposite. Saying newer synthetics will not do this. However you can search for hours and find no definite results as to a yes or no scenario. I think I’d stick with the hard facts that have been experienced rather than the endless online oil speculations.
While we’re on the topic of oil...Let’s talk about oil changes during break-ins.
As you can imagine, during the break-in process plenty of metal shards and flakes are generated. The best solution is to change the oil within the first 20 miles. What we want to prevent is that loose metal from embedding into the transmission and oil bathed bearings within the engine. What does an oil change cost VS a new top end. It’s minuscule. Cheap insurance in my eyes. If you can’t afford to dump your oil in 20 miles should you really be investing in rebuilding the top end? Just do it. Proof in the puddin'
Below are two different pistons from the same style bike. Both assembled at the factory with no radical variables except for the "hard break in" vs "soft break in".
As you can see the results are extremely drastic. One showing heavy blow by the first couple rings and the other looking seemingly unused besides some very light piston scuffing on the skirt. If you don't believe this photo feel free to check out MotoTuneUSA's Piston museum which all use this method and look impossibly clean! Here. There are many other methods for break-ins and other methods including this same style break in on the track and dyno. Since most of my readers are garage warriors I keep my content to that which might be more relative to them. This is one of many options for you to consider. I am by no means saying this is the only way to perform a "proper" break in. It's just something that works flawlessly for me on four stroke motors and I would like to share in my success! If you have questions or statements about this method or any other specific mentioned in this article, PLEASE feel free to e-mail me so I can keep myself and readers updated. Or you can join our community forum HERE for similar conversation and questions among others.
Hey guys! Steen here, working to bring Moped/scooter content to you in unique and thought provoking ways! If you would like me to write about something specific please reach out to me @breakthecyclemotoworks on IG. Either way, thank you for reading! Please remember this is a one woman show, if you found this blog, or any of my writings helpful or funny, please consider simply clicking an ad that you find interesting or becoming a patron on Patreon (See link below). I will have exclusive content up there soon, along with some videos to keep the wheels turning. Even if its only a few cents a month, I will eventually be able to afford a cup of coffee per day! Again thanks so much for reading! You guys are the best! <3 -Steen
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