Author Topic: How to run in the engine??  (Read 1116 times)

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Offline emilios

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How to run in the engine??
« on: November 21, 2013, 11:20:08 AM »
Hi
I just rebuilt a K0 engine..everything new...like a rebuilt should be...new chains..chain tensioners..bearings..pistons...valves..etc..
my question is till how much rpm should i run the bike??
Thanks

Offline nancy

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Re: How to run in the engine??
« Reply #1 on: November 21, 2013, 11:51:41 AM »
This is how I have done it..but i am NOT an expert.
Initial start up needs care - don't let it either rev or chug. No idling. Give it steady 20-30 secs 1500 - 2500 rpm. Off.
Next startup and run - keep revs under 4,000 - but keep a good work ethic going on the motor. Keep the revs climbing and go up and down the gears. Give it a handful and then let it slow back down -down a gear -  followed by another handful. I did this for about 100km...over 3 rides I guess.
Dump your 1st oil inside 400km or so.
Run the bike harder rather than more softly from now on. Rings work in well this way. Give it some!
Avoid steady paced engine running.
Mark

Offline iron_worker

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Re: How to run in the engine??
« Reply #2 on: November 21, 2013, 12:17:06 PM »
My method (and there are lots of them out there):

-Try not to idle the engine when breaking in (especially on the first few runs)
-Do not rev over 5k for the first couple or rides
-After that, do not rev over 6k for the first 1500 miles
-No steady state riding
-Load up the engine/accelerate. Give it lots of throttle but keep in mind the 6k rev limiter.
-Try to stay out of traffic! Rings that are breaking in produce more heat. You need the wind moving over the bike as much as possible.
-I changed my oil at 50 miles, 200 miles, 500 miles, and 1500 miles. It was amazing how black my oil was on the first oil changes but you should see it clear up over the next few. There were also a few shiny bits in the oil the first couple changes and I'm told this is normal but should also taper off over the next few changes. It also is a good idea to run a magnetic drain plug or epoxy a magnet to the filter if possible to pick up any ferous shavings.

That was my method and I think it worked OK... though I'm tearing into the engine again this winter due to an oil leak anyway. ha  ::)

IW

Offline Jerry Rxman Griffin aka MuthaF'er

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Re: How to run in the engine??
« Reply #3 on: November 21, 2013, 12:59:22 PM »
My take:

Be SURE it's mechanically sound first. Then like said vary the revs. I keep them under the sweet spot where they want to take off with a limit of 5-6K. Give it a nice ride or two away from city traffic. Start increasing the rpm load around 100 miles. At say 500 miles change the oil and drop the hammer just don't run the piss out of it YET. You'll get the feel of when it needs to happen. Remember, these bikes don't like to lug around. They WANT to have the #$%* run outta them on occasion, just not no lugging initially.
As of today 3/13/2012 my original owner 75 CB750F has made it through 3 wives, er EX-wives. Free at last.  ;-)

Offline Vinhead1957

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Re: How to run in the engine??
« Reply #4 on: November 21, 2013, 02:17:55 PM »
Also break it in on non synthetic oil!  The regular oil allows the normal break in process

Offline Dream750

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Re: How to run in the engine??
« Reply #5 on: November 21, 2013, 05:27:20 PM »
I use the 750 K1 to K6 owners manual as a guide for stock or nearly stock engines. Since you have a 750 K0, you get an extra 500 rpm on the red zone limit upon reaching the 1,000 mile mark. 

Offline emilios

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Re: How to run in the engine??
« Reply #6 on: November 22, 2013, 08:08:40 AM »
Thank you all!!!
Its my first K0..and everything is stock..except 0.25 pistons...so i want to run engine in correct..
Now i know how to do it..
Thanks again!!!

Offline ncstatecamp

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Re: How to run in the engine??
« Reply #7 on: November 24, 2013, 10:34:55 AM »
Do all of these apply if it's only top end and no bearing replacement? If I only do rings, lap valves new seals and hone, is the procedure the same?

Offline PeWe

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Re: How to run in the engine??
« Reply #8 on: November 24, 2013, 12:09:35 PM »
What about this?
http://www.mototuneusa.com/break_in_secrets.htm

I read  a technical thesis written by a guy in a technical colleague that had made tests and verified the hard brake in as good when verifying the pistons afterwards. He linked to the link above.
The hard brake in make the piston rings to seal better. I'll do that this time. Heavy acceleration followed by decelerations. Very important the first short period while the hone pattern is still there....
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CB750 K2-75 Parts assembled to a stock K2

Updates of the CB750 K6 -1976
http://forums.sohc4.net/index.php/topic,180468.msg2092136.html#msg2092136
The billet block build thread
http://forums.sohc4.net/index.php/topic,49438.msg1863571.html#msg1863571
CB750 K2 -1975  build thread
http://forums.sohc4.net/index.php/topic,168243.msg1948381.html#msg1948381
K2 engine build thread. For a complete CB750 -75
http://forums.sohc4.net/index.php/topic,180088.msg2088008.html#msg2088008
Carb jetting, a long story Mikuni TMR32
http://forums.sohc4.net/index.php/topic,179479.msg2104967.html#msg2104967

Offline ncstatecamp

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Re: How to run in the engine??
« Reply #9 on: December 03, 2013, 11:02:32 AM »
If I'm just lapping valves and honing cylinders do I need to use a zinc additive when breaking it in? Not sure if rings are necessary yet.

Offline Jerry Rxman Griffin aka MuthaF'er

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Re: How to run in the engine??
« Reply #10 on: December 03, 2013, 11:19:36 AM »
Just use standard 'motorcycle' oil and you'll be fine. It has more zinc than 'regular' oil you'd get for your car.
As of today 3/13/2012 my original owner 75 CB750F has made it through 3 wives, er EX-wives. Free at last.  ;-)

Offline lrutt

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Re: How to run in the engine??
« Reply #11 on: December 03, 2013, 11:54:56 AM »
I tried the std breakin procedure (read taking it somewhat easy) on a 1970 Triumph and that sucker smoked like a #$%*. So, nothing to lose, I thrashed the hell out of it to try and force the rings to seat better. After couple bouts of that she's been smoke free now for 3 years. Crazy I know but what can I say, it worked.

Ditto sticking with dino oil for several thousand miles.
06 Harley Sporster 1200C, 06 Triumph Scrambler, 01 Ducati Chromo 900, 01 Honda XR650L, 94 Harley Heritage, 88 Honda Hawk GT, 84 Yamaha Virago 1000, 78 Honda 750K w/sidecar, 77 Moto Guzzi Lemans 850, 76 Honda CB750K, 73 Norton 850, 73 Honda Z50, 70 & 65 Honda Trail 90, 70 & 71 Triumph 650s, 65 Honda 305 Dream, 81 Honda 70 Passport, 70 Suzuki T250II, 71 Yamaha 360 RT1B, 77 BMW R75/7, 75 Honda CB550K, 70 Honda CT70

Offline goldarrow

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Re: How to run in the engine??
« Reply #12 on: December 03, 2013, 07:25:59 PM »
Ride it hard, ride it the way it's supposed to be ridden.  Ride it hard
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