BikerBoy wrote:just smash it to redline
Engines don't come from the factory without being tested, and they do redline them right off the assembly
line to test them, so your engine has already being beaten in.
they recommend those 'break in' rpm limits, just in case someone forgot to add add a critical screw or bolt, better that
something fails at 3000 rpm speeds than 12,000 rpm speeds.
google motorcycle break in.
As I said , DO NOT baby it early in life or you'll have a slug (comparatively) for the rest of it's life.Saki is on the right track also but to correct , it's the COMPRESSION rings particularly the top ring which relies on combustion pressure acting on the back side of the ring to force it against the cylinder wall creating the seal NOT ring tension so much as many people believe!! Secondly , as the engine RPM's increase , the con' rods , pistons and to some extent valves actually 'stretch' as they suddenly change direction at the end of the stroke.
The significance of this in that if you were to 'baby' the motor the rings never reach their proper maximum limits nor do the compression rings properly seal against the cylinder walls!!
If you DO fang the ass of it too early all you will do is open the door for galling and heat distortion of bores , valve heads etc and potentially cause a lot of undue wear to many critical engine components!!
The biggest killer of a new engine and cog box is HEAT more so than load / RPM!! This is why you take it up the rev range and allow the bike / car / truck /whatever to coast back down to gently and evenly distribute / dissipate localised 'hot spots'.
Localised overheating (which may well NOT register on your temp gauge) is caused by tight clearances and excessive / prolonged high RPM!!
Now I don't think there are too many folks on this forum with a belly tanker or similar complete with oil temp / pressure readings , oil cooler temp , coolant temp and /or a data logger etc etc etc.... All we all rely on is a simple idiot light and a single temp sender unit!!
Facts;
-These days almost all vehicle manufacturers do a pre delivery engine 'stress' test - This is only for a few seconds normally and if bits were gonna fall off this would be a good time rather than on the road! It's basically to make sure it runs on all cylinders , is responsive , has oil pressure , no rattles/bangs/knocks etc.
This is done in neutral NOT under load generally.
-The longer you keep the RPM's low on a new bike the less chance you'll be marching back though the dealer's door demanding warranty!!
-There are NO shavings from the rings or cylinder bores during run in as such!!! If you got shavings , you got a BLOWN ENGINE!!!
[most 'shavings come from gearbox teeth,oil pump drives etc NOT bores]anyone heard of 'Nikasil' / chromed bores in the KX's etc??
Now I could go on and on here but I'll lose most people and bore the rest shitless!!
Point being we can guess all we like and listen to all manner of garble but 90% is pure speculation loosely based on fact!!
Without trying to sound like a wanker, I have been building performance and racing engines for both 2 and 4 stroke motorcycles for about 25 years. In that time I have also spent a hell of a lot of time with some of Oz's fastest road vehicles including Sprinters , super saloons , most drag racing catagories yaadda yaadda!!
Basically I've seen the guts of a LOT of different engines and built some pretty tough runners in my time. I have absolutely no reason to bullshit anyone here as I have absolutely NOTHING to gain by it!
What I have written on these posts is based on my experience same as 'Strika' or 'Wattie' for example may impart their knowledge on cornering techniques or 'Dave suspension set ups etc etc.
Hey I don't know every farkin thing but I'll happily advise / assist fello KSRCians who have had an ear full of bullshit by some squeezer trying to stroke their ego or relieve ya's of your hard earned cash if I can!!
Ps; When I get my arse over your way I'll need some of you buggers to show me how to to do REAL corners again!!! ie Track days
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