45 Break-in Oil

[Rex]

Cylinders honed, new rings, valves, and guides in my 45. Should I use oil other than HD50 for break-in?
Some suggestions have been:

1. Straight 30wt for the first hour.
2. HD 20/50 for first 2 hours.

I have some Exxon straight 40wt. Close enough?

During the top end rebuild, I found both cylinders glazed after 118 miles. There were multiple air leaks causing overheating, but they're repaired now.

[AdminGuy]

I'd go with the 20/50. flat ground. stop and start. progressively build speed dependant upon how engine was built. You want those rings to embed and seat. Do you run an modern oil filter?

anyone else?

[Rex]

AdminGuy-

Engine break in is definately one of the most controversial subjects available for discussion, with strong opinions for and against every option available. I did find an explaination of why the variation in speed is required at http://mototuneusa.com/break_in_secrets.htm .

I do have a replica canister type oil filter for Pans and Knuckes plumbed into the oil return line, and plenty of flat ground here in north eastern IL.

Rex

[Jack_Hester]

This may be a bit lengthy. It comes directly from what I have posted on my website, and other places:

Note: This is the manner that I have taken, after quite a few years of trying everything. I've narrowed it down to these steps, as I use synthetics (exclusively) as my lubricants. I have proven that they can be run in vintage machines, fresh rebuild, starting at break-in. If this bothers anyone, it is not intended to do so. I've read quite a few methods online, on other websites. I don't agree with all. Nor would anyone. Including mine. But, I post it here for those who haven't given it much thought. I have, as engines (particularly, vintage) are a passion with me. And, I want them to last forever. So, here goes:

New engine or complete rebuild:

1 - Run first until warm to the touch, on the cylinders. Moderate to fast idle. I'm usually adjusting the carburetor low speed setting.

2 - Let sit for 10 or 15 minutes, and snug all head bolts and cylinder base nuts (no thru bolts on any of the machines I deal with).

3 - Let sit until cool down to ambient temp..

4 - Run until warm to the touch, as in first step.

5 - Repeat 2nd step, except snug head bolts, only. Feeling for creep, fingertips only, and not pulling hard.

6 - Cool down to ambient temp..

7 - Repeat steps 4,5 & 6, until no creep felt in head bolts.

8 - Hit the back roads with no traffic, accelerating easy, never lugging the engine in any gear. Time the ride to coicide with a cool-down stop, every 15 or so minutes. Cool-down means I don't burn my hand, when I'm checking the temperature. Back side of the hand and fingers, only. Nothing like holding on to the handlebars with a blister. I try to make these first trips in the cool of the evening. Winter is my favorite break-in season.

9 - Repeat step 8 for a couple of weeks, never getting over 45 - 50 mph in high gear, on level ground. Never run in high, for extended periods, when pulling a grade. RPM's are not the issue, so much as the load.

10 - Change the oil, but not the filter. It ain't through working, yet. And, it certainly hasn't gone bad. Don't pay any attention to the miles.

11 - Hit the open road, staying under 60 mph. Ride at mostly varying speeds of 45 to 55 mph. Mostly level roads or easy grades, if possible. Cool-down periods every 30 minutes or so.

12 - Repeat step 11 for a couple of weeks.

13 - Change the oil and filter (it's still working, but just change it) at 500 or so miles, or end of 2 weeks. Whatever comes first.

14 - Repeat steps 11, 12, & 13, change oil and filter at 500 mile intervals up to 2500 miles.

15 - Take it on whatever trips, and whatever road speeds you feel like.

I would have ended the break-in at 1500 or so miles, with dino oil. So, there is only a short extention in miles. Time seems to be the greatest extention.

The tranmission lube gets changed with the second oil change, and the last, before hitting the road for a trip. But, the grade stays the same for the first riding season. I make the jump in grade on the next season. I used to flush with kerosene, but now use syn ATF.

Jack

[Rex]

Thanks Jack!

This sounds like a thorough break in and gives me a solid plan for the next 3 riding seasons!

Rex