phase 2 of break-in: manual is ambiguous

[Argee]

Hello, new-to-me Buddy 170i getting the break-in per the manual. Just ticked over 100 miles, and read "95-310 mile, avoid applying more than 1/2 throttle for extended periods of time". Considering the first phase was "avoid applying more than 1/2 throttle", does this mean I can crack it wider, as long as it's not extended periods of time?


...and what exactly constitutes extended periods of time? I have avoided constant speed for more than 30 seconds, as a general rule.

And I have to ask...why the byzantine break-in? Is this a cast iron cylinder? I have seen good head temp dropss on chrome cylinders after only 90 miles.

[Dooglas]

No need to overly obsess on this. My own opinion is that you should vary your speed as you ride and avoid extended periods at wide open throttle for the next few hundred miles. Mostly, enjoy your scooter.

[skipper20]

Hello, new-to-me Buddy 170i getting the break-in per the manual. Just ticked over 100 miles, and read "95-310 mile, avoid applying more than 1/2 throttle for extended periods of time". Considering the first phase was "avoid applying more than 1/2 throttle", does this mean I can crack it wider, as long as it's not extended periods of time?


...and what exactly constitutes extended periods of time? I have avoided constant speed for more than 30 seconds, as a general rule.

And I have to ask...why the byzantine break-in? Is this a cast iron cylinder? I have seen good head temp dropss on chrome cylinders after only 90 miles.

At just over 100 miles you should be able to go 3/4 throttle for 5 - 10 seconds. As long as you're varying your speeds within this 3/4 throttle range you should be fine. After 500 miles, WOT . Break-in is just a matter of common sense. You'll actually feel the bike start to loosen up so go with that feeling. Above all, enjoy the ride.

Bill in Seattle
'12 170i Italia (AZ scoot)
'14 170i Hooligan

[ericalm]

There are a lot of theories on break in but the only thing they all agree on is varying RPMs, which is the most important part. The specifics, as recommended by the manual, seem almost arbitrary. I prefer a "hard" break in, where I will run it full throttle, just not more than a couple of minutes. I do this for the first 600 miles (or until I change the break in oil).

I suspect the numbers are all very conservative and that a shorter period would suffice, but they're also written for all new owners, some of whom may not even know that it has anything to do with a cylinder and piston rings. I've heard a lot of stories of people buying a new scoot and immediately taking it out on a long ride at full throttle.

[k1dude]

I always assumed break-in was about 50% to help seat the rings, and the other 50% was to prevent grooving the variator at a constant RPM.

[Argee]

Thanks for the advice. Yeah, it seemed awful arbitrary and conservative. I've done hard break-in on nikasil, just not sure what this jug is made of. I also figured 50% "other things", such as the variator, bearings, brakes, etc. for newbies, just so they don't dump the bike.

I think next week it's time for a 3/4-throttle ride in the country...

[george54]

IIRC, my Piaggio manual says only 80% throttle until 600 miles and avoid extended time at a single, constant speed. And that's it. Don't obsess too much. You see "extended periods of time" as 30 seconds, and I see it as 20-30 minutes.LOL

[GregsBuddy]

Ride it with a light hand for 160 miles.
Change the oil and filter.
Ride it a little harder for 840 miles.
Change the oil.
Go!

[BuddyRaton]

The "hard" break in method is primarily based on race motors and one obscure article with no references that many have latched on to.

I think the hard method is fine for setting rings...but that is not the only part of the motor that is new. Everything is new...especially the bearings. The last thing I want to do is overheat a bearing that isn't broken in. Race motors typically change out the top end or head so bearings aren't an issue.

That being said it is the first 100 miles that is critical. That and the fact that Buddy motors are tough suckers. I don't think there is a "bad" way of breaking them in but do vary rpms.

[lovemysan]

I have 5k miles on my 161 cylinder with a hard break in. Had the piston out for a crank swap and it was mint, best looking used piston I've ever pulled. Ring seal was excellent. For my new crank break in I rode the bike normally. I did nothing different. I went full throttle with less than 20 minutes run time. Ball bearings don't break in, they either are good or not. Heat, contaminates, poor Machining, over revved stuff like that kills them. When I install a new cylinder I high idle the bike for 10 minutes change the oil and go for a 10-20 minute ride. Slowly increasing to 3/4 throttle for short 10 second burst of a acel then decel. Cool the engine, change the oil again. Ride normally. No extended high speed for a few hundred miles.

[GregsBuddy]

Yes, ball bearings don't "break in" in the normal sense. They require very little lubrication which is one reason they are chosen for small displacement four strokes and all two strokes (no pressurized, circulated oil lubrication system).

[BuddyRaton]

Perhaps "break in" was the wrong term to use for the bearings but unless they are sealed you do want to get them properly lubricated under running conditions.

My point is that everyone concentrates on the top end while there is a lot more going on in a new engine.

[GregsBuddy]

Cam lobe-to-rocker and valve guides are about it.
The rings and piston are the primary concern.