Breaking in a NEW ENGINE

[HDANGEL15]

First post here, I am a long distance rider that has spent the last year having my 03 fatboy with 70K on it totally rebuilt. I am not as savy as 99% of you here in talking stroke/bore etc..but I believe it's 103 now...and used mostly all Screaming Eagle parts where I could.

THE REAL question here is how many miles I need to ride for break -in..and how varied does the mileage need to be?

It was purple and green flames..(old pic attached) ....and is now flat black ...will pin stirpe it when I find / meet someone with old skool talents that i respect for some flash....

it's quite a change for me..It has full sized road king bags on it, and a luggage rack and sissy bar for my ample campin gear as well.

I guess i should go to the main boards to post about who I am...but not sure if this is the correct place to be asking this Question?

[shovelmike]

Welcome HDangel 15. Hold your speed below 60 mph for the first 500 miles as when the bike was new. It would be advisable to change the oil after the first 1000 miles. Avoid parade use or heavy stop and go traffic, this is especially critical in hot weather. In a new engine there are a lot of parts mating together producing extra friction, thus extra heat, you want to avoid overheating as this would take the temper out of the piston rings and also increase the chance of a piston scuffing or seizing.
As long as you use common sense and caution you'll be fine.

[evoKENevo]

Welcome aboard,Angel
There's bound to be a number of different theories posted here on how best to break in an engine...and Shovel's is definitely a good way. In the OLD days when I rebuilt an engine I'd break it in easy for the 1st. 100 miles on fossil oil...change the fossil oil (all I used back then)and then ride'm like I stole'em...no problems

Just recently, I rebuilt my Evo engine...rode it under 50mph for the 1st 100 miles or so using 20w50 fossil oil...changed the oil with 20w50 fossil oil again...rode it pretty easy for the next 500 miles...changed fossil oil again...rode it "normally" (am older now) for another 1000 miles and changed ALL my fluids to Mobil 1 synth...15w50 engine...mercon-v ATF in primary...90w145 gear lube in trans...the bike (running great now) seems to really like the stuff and I'm back to changing fluids at normal intervals...

NOTE: synth oil (whatever brand) is great stuff...but do NOT try to break your engine in on it...just TOO slippery (so to speak) for that.

[frisco-rigid]

Hi HD

I've broken in alota motors.. I'm in the "slow easy" motor break-in camp..

If it was my motor I'd do much as Mike sugg's..
Under 60 for 50 - 100 miles and change oil, fossil oil like Ken sugg's for at least 2K miles..
Me, I never use Syn oil---- your call, whatever turns ya on..

NO LUGGING,, high Rpm's is better than low Rpm's anyday..


Then cool and easy, no more than 3500 Rpm's for about 1500 - 2000 miles, then you're done, have a ball..
Oil change at 500, then 1000, then 2000..
After break-in,, I do oil every 3500 +-..

NO LUGGING- EVER..

[milindh]

My Dad was a 45 year truck mechanic and later service manager for a big fleet of car haulers in Flint, Michigan. Until the early seventies when they went diesel, they ran gasoline engines in the trucks. Chevy big sixes, then Chevy small block V-8's, then 348/409's, and finally 396/427/454's and some GMC big V-6's. They rebuilt and overhauled all their engines in house and the mechanics removed the engines, turned them over to Charlie the machine shop guy who did all the machine work and put the engine back together. Then the mechanics installed the rebuilt or overhauled engine back in the truck. Once it was up and running the mechanic took the truck out on the road to do an accelerated break in of between 100 and 300 miles. That accelerated break in was mainly to seat the piston rings in the cylinders. The truck was going back on the line the next day and having the rings seated was considered the most important aspect of the process. My Dad said he would start out as easy as possible without lugging the engine at all (like Frisco said). The idea was that if too much burnt gas went past the piston rings it would gall and glaze the cylinders before a proper seal could be established. All the cross hatch cylinder honing would get scored. The mechanic was given this job because the engine was his "baby" and he would do it right. A driver might just get in the truck and put the hammer down.

Anyway, Michigan is pretty flat but there are also a lot of gentle hills around and my Dad (and the other mechanics) would find those hills and take the unladen truck up the hill all the while keeping the load off the engine by applying only moderate throttle and liberal use of the lower gears. Get up a good speed and on the down side of the hills he would get off the throttle completely and let the engine slow the truck down with little or no brakes. This allowed oil to go up past the rings with almost no gas pressure holding it back. He said that oil doing that sped up the seating of the rings just like an oiled sharpening stone will sharpen a knife faster than a dry stone. Each successive hill the engine got stronger and stronger. Even on level ground he would always vary the throttle and back off as much as possible. At the end of the day that truck was as broke in as it was going to get in that short time and the rings were safely seated. The rest of the engine components would have to break in in due course and they did.

The point here is not that you can do this process with your bike in one day and then go about your business as usual. Those trucks didn't have the option of a long break-in period while bikers do. The point is to get those rings seated as quickly and easily as possible and that is done when you're off the throttle. Don't lug the engine and try to not just keep the throttle constant for long periods of time until those rings are seated. This is not my advice. This was my Dad's advice.

[evoKENevo]

"Yep"...speed up & slow down,gently...no constant speed OR lugging...sorry I did'nt THUNK to mention...

Meanwhile...F.Y.I.or W.I.W...although I woud'nt recommend the following to anyone these days...as long as we're on the subject, how many here are aware (or care) that when CHEVY brought out their first V-8s there was a break-in problem (ring seating) they solved by telling their dealer mechanics (service bulletin) to dump the likes of "Bon-Ami" (scowering powder) into carbs with engine running...really...no bull !!!

[HDANGEL15]

wow THANKS GUYS.....I knew I would get many and varied answers.
I have heard mostly from people I talked to initially, vARIED SPEEDS is the most important, that I can't just haul ass 1000 miles 60/70/80 or so....and get the oil changed. Not to over simplify the process...but this bike has been down almost ONE FULL YEAR....in the process I rode the piss out of my 99 heritage softail (which also has over 75K on it)...

Long story short, I did a 2000 mile ride; 4th of July weekend, and that baby is bleeding oil everywhere, smoking and burning it bad...so she is parked for a long while I am sad to say. I want this fatboy back so badly and to finish off the summer and fall riding with some power..she is gonna be a real PHATboy..although I call her ROADBOY....cause she has my roadking bags..

keep the OPINIONS coming...more is good

[JCourneyaP]

You will have it broken in in no time. You be surprised how fast it goes.

I also agree with the slow and easy method.........

[evoKENevo]

Just a note here to point out that I just corrected/edited my 1st. post here...because I'd said I changed to synth oil after riding only 500 miles on fossil oil after the 100 mile oil change...and actually ran the fossil oil a total of 1600 miles...small error = big difference sorry !!

[mgmmgm]

How about this method for breaking in an engine? Break In Secrets--How To Break In New Motorcycle and Car Engines For More Power