Going Full Throttle

Big Dog Motorcycle Company is adamant about proper break-in for their engines.  So is S&S and us, Gateway Big Dog.  We consistently find that the bikes that were broken-in properly are stronger running machines.  So, when exactly can you begin to start “leaning” on the throttle?

After Break-In.  There are many components inside the engine that are getting to know one another, and this takes a little time.  Generally, about 800 miles seems to be optimum.  During the break-in process, we like for the engine to be taken no higher than 3200 rpm’s.  This will easily get you down the highway at over 80 mph in 6th gear.  The engine likes to be taken to 3000 rpm then shifted into the next gear.  Each transmission shift will, roughly, drop rpm by 1000.  So when you shift at 3000 rpm, the tach will show you are now at 2000 rpm.  Anything below 2000 rpm for extended riding is lugging the engine, that’s why 3000 rpm is the shift point for cruising.  When you find yourself cruising below 2000 rpm, down shift to the previous gear.  Your engine will thank you.

After the engine is broken-in, there is still a time when it’s not best to bring rpm past 3200.  What time is that?  Anytime before your engine is at full operating temperature.  No temperature gauge?  No problem.  The rear rocker box is an excellent gauge to let you know when she’s ready to go.  I always take the front side of two fingers and touch the rockerbox to feel the temperature in the engine.  If you can hold you fingers down on it and keep them there, she’s not at full operating temperature yet.  It may be warm, in fact it may be very warm but if you can keep your fingers there without being uncomfortable, give the engine more time.  Here’s what is happening.  The aluminum engine grows as it is heated.  We’ve measured from the motor mounts to the top of a rockerbox on a cold engine then brought is up to full operating temperature and re-measured a .050 increase.  What does that mean to you and me?  As you engine is increasing in temperature it’s physically getting larger and this makes all of the gasket sealing surfaces to get tighter and tighter.  At full operating temperature, it’s nearly impossible for a gasket to leak oil.  When you always allow the engine to come up in temperature before you “hammer” it, you will likely enjoy a leak-free engine. 

Remember, you can ride the bike with a cold engine but nothing over 3200 rpm until you can no longer touch the rockerbox.