WEIRD ENGINE BREAK IN?

Hey guys, I´m about to get my hands back on my ´84 GPz550 right after a top end rebuild (see this thread if u want: kzrider.com/component/option,com_joomlab...w/id,100761/catid,2/

Some fellow at www.gpz550.com suggested me this un-tyipical break-in procedure:

www.mototuneusa.com/break_in_secrets.htm

Frankly, this goes against everything I´ve heard about a proper engine break-in. What do you you think about this, guys? Will I smash my engine (and blow away 500 bucks BTW) or will I breed a zinger?

Post edited by: kawadruida, at: 2007/01/24 18:02

Post edited by: kawadruida, at: 2007/01/24 18:26

Post edited by: kawadruida, at: 2007/01/24 20:36

Not weird to me. That's the way I've always broken one in. Run it moderately hard, make sure you're changing engine speed frequently. One old guy always said:
"What you get it used to in breakin, it'll do well the rest of its life." I don't know about the logic, but it's always seemed true.

makes sense to me too. just remember 30 min oil change,250 mile oil change and 500 mile oil change;)

They guy is 100% right. Give it heaps right from the beginning provided engine is warm.

Engine performance has a lot to do with ring sealing and you have to get the maximum gas pressure in the cylinder to do this properly.Its the gas pressure behind the rings that forces them against the bore in the bedding in process. Too lite handed and they never seal properly. Also this is great fun!!!!

I used this approach with my J which had a new Wiseco kit fitted. No problems at all. My problem was finding a piece of street where I could load the engine. 5.30 Am Sunday morning on a steep piece of freeway. 140KPH in third before I frightened myself to death but up a steep incline and repeated half a dozen times.

Like you I was a bit anxious about it so spoke to a specialist who rebuilds antique Manx Nortons. Runs them hard at 5000rpm to bed the rings using mineral oil lubricant. Once completed given an oil change and move to normal lubricant.

have a look at the UK site www.z1ownersclub.co.uk/index.php where I beleive there is a thread on the subject.

Post edited by: Kiwiz, at: 2007/01/24 18:53

Kiwiz wrote:

Like you I was a bit anxious about it so spoke to a specialist who rebuilds antique Manx Nortons. Runs them hard at 5000rpm to bed the rings using mineral oil lubricant. Once completed given an oil change and move to normal lubricant.

have a look at the UK site www.z1ownersclub.co.uk/index.php where I beleive there is a thread on the subject.

Post edited by: Kiwiz, at: 2007/01/24 18:53

Isn´t mineral oil the "normal" one, as opposed to the synthetic? Please enlighten me here fellas...

Post edited by: kawadruida, at: 2007/01/24 20:35

Post edited by: kawadruida, at: 2007/01/24 20:35

it makes sense, just make sure the engine is up to temp before you blast on it.
my uncle's 548ci drag vette's break in (after reaching the right temp)was a burn out and a trip down the 1/4

Here is how I was taught to break in a bike motor.

Let it warm up for only a minute or two at idle. Then bring the rpm up slightly revving it in stages that gradually increase the rpm. Give it a couple of high rpm squirts. Shut 'er down and check everything for leaks. If there are no problems, fire 'er up and ride it like you stole it.

Have fun.

Cheers-Colin Firth - Ontario Canada
1977Kz 650 Custom-Bought new by brother. 14K miles on chassis. First rebuild was Wiseco 700 kit. Latest rebirth includes 810 big bore, Wired George Mikuni 29 smoothbores and lottsa go-fast goodies. Miss January on the 2007 Kzrider.com calendar.

Aircraft engines have been broken in like this for ever.

Standard break in procedures for air-cooled piston aircraft engines: Run at least 75% power for the first 10 hours, varying rpm for 5 mins (throttle back to 65%) every 15.

On my KZ1000, 75% is 60 HP. Take a look at your power curve and you will find that 75% power is like riding around all day at highway speeds in third gear.

The danger in this is that cylinder head temps and oil temps are very near the red line until the rings seat. Lacking a CHT gauge and oil temp gauge on your average KZ, I wouldn't do this on a real hot day...

Use only mineral oil for the first 50 hours after overhaul.

Change the oil and filter at 10, 25 and 50 hours.

Post edited by: andoman, at: 2007/01/25 11:16

Note to those in mile high cities with normally aspirated bikes: at 8000 feet, at the top of the HP curve, the engine will only make 75% of rated sea level HP.

Post edited by: andoman, at: 2007/01/25 11:17

Mineral oil? Like every day mineral oil from the drug store? Isn't that a bit thin?

Why do you do this after a rebuild/overhaul?

Please explain the difference between mineral oil and normal oil, I always thought mineral (petrol based) oil was the normal one and that synthetic oils were the "modern" oils...

here most of the oil sold by auto retailers here are multigrade sytnthetics.

I am no oil expert but I think these are fine for the bike once run in. By mineral oil I mean the type often labelled "for older engines" which lack all the additives to prevent wear. During run it you are encouraging wear between rings and bore to get a seal. Once done important to change oil as it will be full of metallic particles. Probably no reason why you couldn't stick with mineral from thereon but modern oils probably better given that they are designed to reduce wear, good after break in and are easier to obtain.