Modern Street Bike Break-in: UPDATE 2012 - Event Date: January/01/1900

Guys,

Be sure to read my street engine break-in procedure, especially if you built your own engine: https://forums.brocksperformance.com/forum_posts.asp?TID=6&title=streetbike-engine-breakin-procedure

Otherwise, most areas of that old article (after initial start-up) applies to your new Sportbike... especially the part about NOT being afraid to get on it!

I'm not saying to stomp the hell out of your new bike (although, "ride it like you stole it" has worked for many riders - and was the recent advice from one of the top sources available,) but I will say that there are numerous reasons to get close to redline -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 remember:

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 few minutes of operation. Your rings were most likely seated at Kawasaki/Suzuki, etc...  before you ever 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, and flex just to name a few.  This is the reason we are so specific about measured assembled clearance with our Top End Kits: http://brocksperformance.com/content/Instructions/OTHER/BBP-MAC.pdf

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.

FYI:  Once the rings collide with a thick carbon layer, the above mentioned problems can occur. Some bikes recover just fine, and some don't ever make the correct power until the damaged rings are replaced. Naturally, some build up is normal, but occasional high RPM operation helps prevent the 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 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 fully synthetic because we see more bearing issues than problems with the rings seating, especially with after-market billet crankshafts.

Of course, I would have NEVER performed a full load tuning session on the dyno with my brand new ZX-14 without following our proper break-in.  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 aggressive power delivery with only VERY timid operation from ‘grandpa-type’ riders being the main culprits of poor power output. Understand, I would never suggest anyone break the law or put themselves or anyone else at risk on the street, but I would suggest that you look for your local drag strip and go play!

Brock

PS. Don't believe me? Check out this article from August 2018 from Engine Labs: https://www.enginelabs.com/news/dispelling-engine-break-in-myths-with-high-performance-academy/