Running engine in ?

[Anonymous]

Ive just done the top end of my GS1000 had the bores honed and new rings fitted and decoked the head lapped valves in,im assuming the engine will need running in now its got new internals what milage should this be and what speed - revs should be used.
Thanks Trev

[Anonymous]

Seems like there are many different ideas on this topic & I couldn't say any of them are wrong. My opinion is don't run the same speed for any extended period of time. Wouldn't exceed 4000 rpm for 50 or so miles, no redine for at least 100 or 150 mi. Don't baby it, but don't abuse it either. Main thing don't put it on 50 or 65 or 75 mph and keep it there for a half hr.

[gspaul]

Stay off the freeway,the rev's really need to be going up and to seat the ring's.
The last post is right don't baby it, just ride as you would.

[Footy.]

Re: Running engine in ?

Ive just done the top end of my GS1000 had the bores honed and new rings fitted and decoked the head lapped valves in,im assuming the engine will need running in now its got new internals what milage should this be and what speed - revs should be used.
Thanks Trev

Hi Trev, a fellow Brit GS'er!

DO NOT use semi or fully synthetic oil as a first fill. These have far more chance of glazing the new ring and bore surfaces. Just use a basic mineral oil for 5 or 6 hundred miles, then change oil and filter. You can re-fill with a better oil then.

Don't let the engine idle for long periods, and vary the load as much as you can giving it the odd hard acceleration during this period.

Footy.

[Anonymous]

I've had this discussion with others, and most agree that the information found at this site is reasonable.

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

[Pete Logan]

Just for the sake of balance, some don't, too

Personally, I like it. Used to know a guy who broke his Minis in this way, way back when, and they always seemed to pull stronger for longer.

Hasn't come up for me, yet. Haven't ever had a new engine, or a rebuilt one.

Pete

[Footy.]

I've had this discussion with others, and most agree that the information found at this site is reasonable.


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

I don't have any real problem with this, other that the basic practicalities of this applied to `our' particular case.

When we have rebuilt our old bike engines, we usually `miss' the window of opportunity described because we have to idle our engines to set up carbs, and ignition etc.

I agree that a good `thrashing' won't do any harm to our engines, based on 35 years experience in the engine reconditioning trade.

The big problem these days is that modern oils are just too `good'! All things considered, if your tolerences are within spec, your not going to seize up your engine, or cause excess wear by `thrashing' it from the start.

The biggest factor in my opinion is to use a `crap' oil to start with that will allow `some' of the minor wear necessary to `bed in' new surfaces.

This is a big issue in rebored modern diesel engines, where the rings and bore hardness is designed to last for the maximum wear life. The problem is how do you get the initial running in wear with these `hard' components? If these engines are not properly bedded in, they will burn oil and smoke all their lives.

In England, Morris `ambester' oil is specialy designed as a `first fill' running in oil for such `dificult' cases.

In my opinion, if you use a `basic' mineral oil to start with, this gives you more time to play with your carbs ignition etc, without missing the window for proper running in described in that article.

Footy.

[feelergaugephil]

I didn't leather my GS1000G after the same stuff you did until 1000miles, AND YES< It drove me crazy going slow, but it pulls like $hit off a shinny shovel now. Don't get caught off the wonderful police camera's after you run it in!

[Pete Logan]

Just in passing, and I'm quite happy to be told I'm full of it (again ), most of what I know in theory comes from Smokey Yunick's writings on tuning the 350 Chev for racing.

This was way back in the early days of synthetic oils, but we are talking 200 horse per liter motors.

Smokey believed that a motor should be broken in on mineral oil before switching to syn, because the syn oil was 'too good' and prevented proper break-in. So far, so good.

But what surprised me was that according to him, a break-in period on mineral oil of 30-60 Minutes was quite sufficient.

When I mentioned previously Mini break-in, the precise method used was to take the car off the showroom floor, point it up the road, and thrash it to valve bounce in each gear. Let it run at max rpm for 30 seconds, stop, turn it around, do the same thing on the way back, and turn it in for its regular 500 mile service.

Like Footy said, though, it would have already had delivery mileage on it.

Personally, I'm with W.O. Bentley. If ya want more horsepower, get a bigger engine

Pete

[tfb]

I agree; use a mineral oil for running-in, steer-clear of the synthetics until she's properly run-in (ie. after about 1000 miles). Now all that follows is my opinion/ views on the art of running an engine in, gleaned from chatting with various blokes who rebuild motorcycle engines for a living...

When the rebuilt engine first fires, take it for a quick strop around the block, up through the gears, back down. Don't thrash it, but don't go too gently, either. But this is just supposed to be a SHORT RUN. Then when you get back, turn the engine off, let her cool down, and go off and make a cuppa tea or have a beer, your choice . Then fire it up again, and go for a longer ride, say 15-20 minutes. Get back, let her cool down. Check and readjust your valve clearances (they will have settled in), and re-torque the head bolts in the sequence as per the manual.

For the next 500 miles, don't be too hard on it, but don't go too gently either. Avoid letting her idle for long periods. Vary your engine speed (RPM) all the time, to avoid bedding things in at a given RPM. At the 500 mile mark or thereabouts, change the oil and filter. After this, give the old girl progressively more curry, and after 1000 miles you should be right for some decent thrashing once again. :twisted:

Now that's just the approach I would take... but since everyone else is putting in their 2-bob's worth, you might as well have mine as well!

Mike.