3 replies [Last post]
ahdoman
ahdoman's picture
 Offline
Santa Clarita, Ca.
Joined: 08/30/2007
Posts: 24

1969 R60/US - I'm getting ready to put the cylinders back on but have a few questions that are not answered in my Clymer manual...
1) Do I use any kind of a sealant on the gasket between the cylinder & case (metal gasket)? How about cylinder & head?
2) What is the break in proceedure?
I think that's it for now unless someone has some extra tips.

oligee7275
oligee7275's picture
 Offline
VBMWMO #7275
Joined: 05/31/2007
Posts: 79
Engine assembly questions - Gaskets & Break in

Hi ahdoman,
No sealant on either.
You said the base gasket is metal?
Mine was paper on a '59 R60 and I used Yamabond.
Generally you don't use a sealant with a metal gasket.
No sealant for your head gasket.
When you install the valve covers make sure the gaskets and surfaces are dry and free of oil. No sealant here either.
As for break in, keep your rpms under 2/3rd top rpm and vary your speeds and don't lug the engine. In other words ride it normally.
Most of your break in will occur within 300-500 miles. Ride some and let it cool then ride more and let it cool (heat cycling).
You could put all 500 miles on in one day if you wanted, just don't do it on the interstate. Running the engine at a steady speed or rpm will not let the parts mate properly.
After each ride check your base nuts for tightness (don't ask me how I know this) and after a few heat cycles retorque the head bolts and recheck valve clearances.
Change oil after 300 miles and after 600 miles just to get crud and swarf out from parts mating.
Others may have different ideas but this is pretty basic.
Hope this helps,
Dean

schrader7032
schrader7032's picture
 Offline
VBMWMO #7032
San Antonio, TX
Joined: 10/27/2006
Posts: 6831
Engine assembly questions - Gaskets & Break in

My take on gaskets and break-in:

- I used Hylomar on the base gasket and it was the metal gasket. That's what the mechanic told me to do. I also used the sealant on the pushrod tube seals. Nothing on the head gasket.

- Break-in...I've heard a lot of people recommend this website for info on break-in:

http://www.mototuneusa.com/break_in_secrets.htm

My approach was the following. I started the bike the first time and as soon as the engine would take enough throttle, I ran the RPMs up to about 3K. I held that for about 45-60 seconds. I then went for a ride. During the ride, I avoided any lengthly periods of idling (over 30 seonds) and varied the RPM probably not exceeding 4K RPM. I shifted a lot in order to get the acceleration and deceleration pressures to work on pushing the rings against the cylinder walls. After the first 20 mile ride, I drained oil. When cool, I checked torque and valve clearances. I changed oil again at 200 and 500 miles. I also checked torque and clearances just to be sure.

I understand the reason for the 45-60 second initial run is to force the rings to wear in before the cylinder walls get glazed with hot oil. Those first few seconds the walls are fairly cool. Once the glazing starts, the amount of roughness and abrasiveness will decrease. I wanted to get the oil out of the bike as soon as possible after that first run in order to minimize the amount of stuff that might fill the slingers.

Seems to have worked so far for me...1000 miles on the engine...going riding this morning!!

Kurt in S.A.

__________________

Kurt in S.A.
'78 R100/7 '69 R69S '52 R25/2

Allan.Atherton
Allan.Atherton's picture
 Offline
VBMWMO #2709
Joined: 10/27/2006
Posts: 507
Engine assembly questions - Gaskets & Break in

"schrader7032" wrote:

... I started the bike the first time and as soon as the engine would take enough throttle, I ran the RPMs up to about 3K. I held that for about 45-60 seconds...

No doubt the factory gave the engines the first start. I wonder if they did it that way with the long revving.

Even those who believe in that initial revving differ:
Some brutalists favor the Bon Ami method. Put a bit of scouring power in the combustion chamber.
Some say put just one drop of oil on the cylinder wall.
Some say put plenty of oil on the cylinder walls.

With my R27 and R69US I just started them normally, then did the the first 600 miles on hilly twisty little 2-lane back roads. No idling, lots of gear changing and braking, upshifting at high rpms, constant short bursts of power and speed followed by backing off, downshifting to 3rd on any long climbs to let the engine spin easy. From 600 to 1000 miles I used a little more of the engine. I did not maintain high cruising speeds until 2000 miles. Their engines broke in well, now have 8K and 11K miles on them, and don't burn any oil between 1000 mile changes, by which time the oil is only dark amber.

Comment viewing options

Select your preferred way to display the comments and click "Save settings" to activate your changes.