Best way to break in a V twin engine?!
 

I just finished up a rebuild on a xb12, complete new lower, and top end. I filled her up with 10w30, and shes purring like a lion. I keep reading different ways to break in the engine. For instance for "x" amount of miles keep it under 3k, then progressively increased. Another is to keep it under 4 grand for the first 500 miles. I know I don't want to redline it obviously, but what do y'all recommend?

Spendy engines are broken on a dyno all things monitored.
With out that tool, most will say a a couple short idles to get things used to each other and check O.P. cooling ETC. (30 sec or so)
Complete cool dwns in between.
Then progressive loads and RPM s.
Each with cool dwns.

New lawnmower?

I am an advocate of drive it hard after 30 seconds of idle. There are numerous a people proving this works and lots of posts online.

Run it hard.

For this type of engine, I agree. Load it up 80% and back off you want to run the gears, rpm's up and down loads on loads off, basically enjoy it save the redline until you have 500 on the clock.

Look, I want to help out a fellow Pelican. Have the bike shipped here, and I will spend this summer laboriously breaking it in for you.

Ask asphaltgambler,
He knows his way around a V twinn. seriously

I let it idle to warm it up, then to completely cool. Did that a few times then I ripped on it. Didn't pass 4k in gear.

http://forums.pelicanparts.com/uploa...1402299213.jpg
It seems like the oil pressure has spiked and started blowing things up.

If you want it to run like a harley, punch a small hole in the crankcase and switch the plug wires around. ;)

You might have the oiling system hooked up wrong, Is there a air oil separator up top ??

Blow by is never a good thing. :(

There is only one correct way to break in piston rings to cylinder walls, several here have already alluded to it. I have built several motors from the crank-up with 100% success, (knock on wood). Here is the break-in guru:

Break In Secrets--How To Break In New Motorcycle and Car Engines For More Power

Whenever I rebuild a motor, I do 3-4 20 minute gentle heat cycles, with complete cool down in between. Then, I let her rip!

You need to consult someone that knows your add ons.
All I can add, Is, There is rubber umbrella oil separators in the rocker boxes that often get installed wrong.
Piston rings can be installed upside dwn.
If one does not their way around a recip lots can be wrong.
If it is a oil blow problem I would think your bottom end is ok .
Did you have Oil P? If so your bearings more then likely had oil.
Big cylinders need to swap air back and forth between crankcase and valve train upstairs .
I am going to guess there is a part in backwards more then anything else.

The xb has just the pcv. The xl evo has the umbrella valve you are talking about.

The engine is running strong now. Thanks for your help!