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Streetbike Engine Break-in Procedure

Printed From: Brock's Performance
Category: Technical Articles and Information
Forum Name: Streetbike Engine Break-in Procedure
Forum Description: Instruction on how to properly break in you streetbike engine
Printed Date: May/26/2022 at 12:45pm
Software Version: Web Wiz Forums 12.01 -

Topic: Streetbike Engine Break-in Procedure
Posted By: Brock
Subject: Streetbike Engine Break-in Procedure
Date Posted: January/21/2003 at 6:36pm
The following streetbike engine break-in procedure is something that I have been gradually perfecting for the past 15 or so years. Every aspect of the process is traceable in some form or another, with many subtle changes occurring along the way. I have received help from other engine builders, most recently as a result of the introduction of after-market plain-bearing crankshafts and the special requirements associated with them.
In this area, I utilized the wisdom and guidance of Mr. Ray Bellucci. The "godfather" is pretty tight-lipped about his secrets, so I won't reveal exactly which aspect it is. You can be assured that I was greatly appreciative of his input, as I'm convinced you will be! 

This is the exact method that I currently use on all streetbikes, from my Team Suzuki Sport GSX-R600 SS to my Unlimited Streetbike Shootout 1500cc Bandit.

Start with regular Quaker State 10W-40 Motor Oil (20w-50 if you can find it , in the green bottle @ $1.25 per quart - no fancy stuff!) to full level in the view window. Remove the spark plugs and turn the engine over with the bike's starter until the oil pressure light goes out (This occasionally takes a while, a battery charger might come in handy). If the light does not go out, investigate the problem! Replace the spark plugs and perform a final safety inspection.

Do not start the engine until you are ready to ride the bike.  If you wait more than an hour, perform the first steps again. 

Make sure the bike is 100% ready to ride. Including: fresh gas, proper air pressure in the tires, double check the rear axle, and triple check the oil drain plug and oil related fittings (oil cooler, etc.). Additionally, ALWAYS use some type of air cleaner and an exhaust baffle. You can ruin your cylinder bore or not hear potential problems(not to mention it is the proper way to ride on the street!). Reset your trip meter and prepare to ride.

Start the bike, adjusting the idle to at least 1700 to 2200 RPM. Look for oil leaks. if you find a leak, turn off the engine and repair the problem. If everything looks good, IMMEDIATELY RIDE THE BIKE. You must gas-load the rings for them to seal properly - do not overload. Ride the bike calmly at first varying the engine RPM and watching for signs of trouble. If something feels wrong, it probably is - STOP THE BIKE AND TRAILER IT HOME. Within the first several minutes, it is not uncommon to have to readjust your idle back down as the rings begin to seat. 

Special Note: If you are serious about this procedure, you should have an oil pressure and a temperature gauge installed. This allows you to actually KNOW if there is a problem. I use a back-lit temperature gauge available from Yoshimura. Street and Competition sells a less expensive version made by Daytona. I made my own oil pressure gauge from parts purchased at NAPA. 

If everything seems to be going well, don't be afraid to get a little aggressive with the gas. Avoid full load, redline rpms. Keep the bike moving - you should avoid heavy traffic and excessive idling or sustained constant RPM on the highway. Try not to allow the bike to stay at any certain RPM for very long. 

Ride the bike for approximately 15 miles.

Return and allow the bike to cool completely (over night is best). You may want to remove the drain plug and allow the oil to drain during this time. Inspect the oil for any debris. Re-install the drain plug and replace the oil with fresh Quaker State - its inexpensive, easy, and very important. You may wish to re-check the torque on the head gasket nuts, but if you use stock or spring steel type gaskets, I have found it to be a waste of time. This is also a good time to check the valve adjustment and perform a compression and leak-down test on the engine.

Next ride, adjust the idle to its proper position and travel approximately 40 to 75 miles. Once again, avoid full load, red line, and long-term high RPM running, but you can be fairly aggressive if conditions allow (this depends on where you live - I am not endorsing breaking the law!). Then allow the bike to cool again. If there are no signs of oil leaks or trouble, I consider the bike ready to race and install a new filter in conjunction with my favorite race oil (check with YOUR engine builder for type and quantity). A bit of personal input for budget conscious riders: I have found that the Quaker State out-performs (on the dyno and race track) all other non-synthetic motor oils that I have tested.

This procedure should be considered a general guideline, not the 
final word. If you feel that these requirements are excessive for your machine, adjust the mileage accordingly. Use your best judgment - it is YOUR engine. Remember, Pro-Mods normally don't receive any break-in (unless you count the burn out), and some engine builders put engines through their paces immediately on the dyno. On the other hand, factory recommendations are far less aggressive, even though most machines today are pre-tested before delivery to the dealers. 

I also use a procedure known as heat cycling, but I have found this to be time-consuming and unnecessary for most street applications.

This entire process can be duplicated on any rear wheel dyno. 

I hope this clears up some of the mysteries in this high-performance world of ours!


Posted By: Brock
Date Posted: May/31/2006 at 5:45pm


Be sure to read my street engine break-in procedure:">

Most areas, after initial start-up, apply to your new ZX-14 (and most 1996 and newer engines), especially the part about not being afraid to get on it! I'm not saying to stomp the hell out of your new bike (like I did in my Diary… J), but there are numerous reasons to get close to red line every once in a while if you want to extract the most HP out of your new ride.

It is important to gas-load the rings for proper seating, BUT…

In the “Old Days”, the rings were harder than the cast iron sleeves. Seating took MUCH LONGER because the entire surface area of the liner had to conform to the harder surface of the ring faces. These days the bore coating is
nickel/silicon carbide based; it takes diamond embedded stones just to hone it! The bore is harder than the ring faces which means only the small surface of the rings has to conform to the bore. I believe this occurs in the first minutes of operation. Your rings were most likely seated at Kawasaki or on your ride home.

I feel it is MORE important to NOT allow a large carbon build-up in the cylinders above the rings. This carbon can scratch your rings and cause high RPM ring “flutter”. We have seen some of the most gently broken-in engines make the LEAST power on the dyno and spray engine oil from the breather when we finally allow the engine to reach high RPM operation. During high-Revs, many variables allow the rings to rise higher in the bore:  rod stretch, piston rock, natural bearing clearance, oil type, flex, etc… just to name a few.  This is the reason we are so specific about measured assembled clearance with our Top End Kits:">

If these items didn’t exist, we could set all engines at zero and be on our way, but they do exist in every combustion engine, so we must compensate accordingly.

If the rings collide with a thick carbon layer, the above mentioned problems can occur. Some bikes recover nicely, but some don’t make the correct power until the damaged rings are replaced. Of course, some build up is normal, but occasional high RPM operation helps prevent damaging thick build up.

Most break-in these days relates more to moving parts in the transmission and drive train in addition to bearing surfaces. Too much load too soon can cause problems. We see very little bearing scuff these days, but it can happen. This is why I have NO PROBLEM using a fully synthetic motor oil much sooner in the life of the engine than in the past. In fact, we actually break-in some big stroker engines on full synthetic because we see more bearing issues than problems with the rings seating, especially with aftermarket billet crankshafts.

I would have NEVER performed a full load tuning session on the dyno with my brand new ZX-14! I know better, but I wasn’t afraid to be aggressive under real-world operating conditions. The good news is that today’s engines are built to withstand these factors with only VERY timid operation from ‘grandpa-type’ riders and extremely poor pump gas being the main culprits. There is very little an operator can do about fuel selection, but the riding is easy and fun.

Of course I would never suggest anyone break the law or put themselves or anyone else at risk on the street, but I can (and will) suggest that you find a drag strip and go play!




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