Breaking in an overhauled engine...
 

I recently changed piston rings, cam tensioners, oil pump, etc etc...people like to say it's like having a new engine...

With that in mind, I was wondering: what is the best way to break it in? The indie mechanic who helped me put it together told me to:

1. Keep the revs low, but no lugging the engine
2. Don't go over 60 mph/100kmh
3. Change all fluids after the first 1,000 miles.

Any other suggestions? Thank you! :icon_bike:

Break in of the piston rings is the biggest reason for the directions he gave you. I would add using alternating speed rpm ranges and never holding one speed for long periods. This goes for any engine not just Harley. Another thing is avoid synthetic oil during break in. Use a good Dino oil first 1000 mile like he told you then switch over. Reason is synthetic can prolong break in period because.....well it's just " slicker" would be easy way to put it. Lubricates to well to let the parts wear in together. Some will argue against that but it's a common practice to break in on Dino before using synthetics.

Btw I'm no Harley engine expert but this stuff applies to other engines so I'd assume it applies here too. There's also another school of though in how to break a engine in but I won't muddy the watar with that lol.

You haven't replaced much that needs "breaking in". The important thing is to get the piston rings to bed in before a glaze builds up on the cylinder wall, and a few hard pulls works well for that.
Baby the engine too much, and the rings may never seat properly.

S&S used to ship their engines pre-filled with 20W-50 Mobil 1. They've got their own product line of lubricants now.

Corvettes are pre-filled at the factory with Mobil 1, IIRC. So is the $2,000,000 Bugati Veyron.

And Bentley.

But there's nothing wrong with running dino oil the first 500 - 1,000 miles.

Then change it because you never know what's in it....... So it's a little cheaper and kinda smart to run dino oil because your rings will break in a little quicker and you're just gonna throw the oil away after a couple weeks anyway.

Peace of mind.

People insist they've run XXYY Oil for years and they've had no problems? That's almost certainly true but what they don't notice is the loss of power they've experienced over a long period of time.

Valves carbon up, rings wear, oil consumption increases, compression lowers.......

In 20,000 miles, you'll still have about the same power you started with if you use good Synthetic while the guy running cheap dino oil can't understand why his bike is losing power and smoke is coming out his exhaust ever time he starts it.

It's worth the extra few dollars.

Hell, even in cars, they're starting to notice that you can get a lot extra out of Synthetic. My new F-150 calls for up to 10,000 miles between oil changes. And that's with Ford's Synthetic Blend

Ain't gonna happen, just saying :icon_shrug:

I did a 107ci last September, followed the break-in instruction and seat the rings nicely. I have 4,000miles now not losing oil at all.
http://www.rollingthundercycles.com/page/395028207

Your mech gave you sound advice, I did exactly that and motor runs strong

Not saying this guy is right or wrong but he is persuasive:

http://mototuneusa.com/break_in_secrets.htm

glad to see you back on the road.. an engine taking a dump on you can be a big deal.. welcome back to the riding world.. congratulations.

Thanks man! A little nervous on how to ride it the first miles though, which is why I'm asking how to break it properly. I've gotten great answers so far! (and some contradicting opinions as well)

What he said. new rings is nothing after 50 miles or so you ride it like you stole it. Don't forget once the engine is warm to get the revs up to about 3200 to 3400 just cruising and nail it up to 5000 to 5400. let off and do it agin then take it home and let it cool and start over.