smoking from new pistons.rings.jugs

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Feb 21, 2005
Hi all:

so the basketcase has about 200 miles of riding after new cylinders, pistons and rings: There's a moderate amount of smoke......(on acceleration and cruising but not deceleration)

how long does it usually take to get the rings bedded in and stop smoking? it seems to be smoking less as time goes on but I'm not 100% sure, and don't like being the annoying smoky guy on the road.

as usual, thanks for your feedback.

I DO , however, like being able to stop at a light and have the baby purr at 800+ rpm's :lol:

I would think smoking would be substantially reduced, if it had existed from the get-go, by 200 miles, BUT, that assumes a "proper" break-in, which is a bit more, um, traumatic than most of us (myself included) tend to inflict on new rings/pistons/bores. By 500 miles or so, on non-nikasil bores, you should be where you're gonna stay and you'll know for sure.

So I wouldn't panic yet, but maybe get a bit more aggressive during the next 300 miles or so - you know the drill, accelerate in 2nd or 3rd gear from 30 MPH to 60 MPH, then off the throttle til back to 30 MPH, repeat 10 times.

You're not using synthetic oil are you? Great stuff, and I wouldn't use anything else for anything BUT break-in, but it will lubricate a bit TOO well for a quick break-in.

Good luck. Don't worry unless and until it's time to worry.
PS, you ain't the smoky guy by a long shot. That's me, and I'll likely be asking you for ring installation tips come next winter. Best - BrianK
The guys at TotalSeal Rings told me once that their recommended procedure is to install rings dry and, "Ride it like you sole it". I use a slight variation in that I do a wipe on wipe off of oil on the cylinder and piston skirt, then I ride it like borrowed it. :D
P.S. to last post. Is there a chance that you installed the rings upsidedown? It will smoke. DAMHIK.
So what oil are you using? If it was honed properly, correct clearance, rings installed correctly it shouldn't have smoked at all, unless you are using some flash oil which may make it smoke. Smokey engines very rarely become 100% right,they alway seem to burn oil even if they stop smoking :|
I believe it is important to use straight dinosaur juice for engine break-in. I used Aero Shell ashless dispersant oil for my break-in. Its a non-detergent, straight 50W oil. Engine never smoked, and I'm approaching 6000 miles since initial start-up.

Actually, it did smoke once. I left it idling for a few minutes on its side stand, and the left jug started smoking. After the initial shock, I realized that oil was pooling around the left exhaust guide, and dribbling down the valve stem because of the angle of the engine. Straightened the bike up, and no more smoke.

After break-in, I switched to Valvoline VR-1 50W, and I change the oil when it starts to look dirty, around 2500 miles.
I used a cheepie honing stone and probably didn't do as good of a job as I should.... figuring that since they were NOS new jugs... maybe that was a bit of a mistake.

I'm pretty sure that I installed the rings correctly as I double checked them a few times. H aven't installed rings in anything since I rebuilt a volkswagen in the early 70's but that went without a hitch.

I'm using castrol gtx: 20-50...... just about time for the first oil change.

I've been babying it: maybe jumping on the throttle up to about 1/2-way but for the most part, keeping in the low RPM range....... maybe I'll start gittin on it a bit......

as I said, it does seem to be getting less and less smokey but it does smoke a bit especially when the engine is hot: maybe if I go with a static 30 or 40w??, since I don't care about having to start it in the freezing cold.....

I'll keep you posted..thanks

If you have not fitted new shell big end bearings and had a crank regrind you can give it some welly, sounds like it needs it.
If you have not fitted new shell big end bearings and had a crank regrind you can give it some welly, sounds like it needs it.

Sorry, my Scottish translator is on the blink, but I think you are saying to get on it a bit....... :) In fact the bottom end was disassembled and inspected but not reground/re-bearinged (is that a word?)

In all candor, I probably only have 150 miles of actual traffic riding on it. noodling around the neighborhood doesn't really count since I barely got it over 2000 rpms during those initial shakedown rides over the last couple of weeks I've been a little less timid about giving it a bit of throttle.

The smoking does seem to be getting less and less........

The good news is that it consistently starts on the second kick when cold, and first kick when warm, (boyer, dyno and pod onboard) and it is overall running very once I get past the first break-in oil change, I feel pretty comfortable that I can venture out on some 50-75 milers and feel sure that I'll get home o.k..

thanks, folks.
I think welly come from the wellington boot, my wife doesn't use that term but her brothers do. Yup, I'd just keep running it myself, sounds like it may be breaking in just fine.
You can have a breaking in discussion just as long as a tire or oil discussion. Personally I go with the varied speed and don't get it too hot or rev the %%$^ out of it myself. Since this has worked for me for many years I'll stick with what has worked.
All of the above advice is good and hopefully it clears up. Assumiong they rings are the right way up, if it doesn't stop smoking then it may be a cause of too big a ring gap at the install. Do you check the ring gap before fiting the pistons?

According to what I've read, the majority of break-in for a new engine occurs in the first 20 minutes run time. The new engines I've seen built by performance shops are brought up to speed on the dyno as soon as oil pressure is up. It makes me cringe, but that's the way it's done. As for bottom ends, I personally think there is very little breaking in if the machining and assembly are done correctly.
If a freshly rebuilt engine still smokes after 5 miles , I would be very worried .

I agree; something is definitely amiss.
Break-in CAN be accomplished quickly, but sometimes it is not, which is why I say I wouldn't push any panic buttons 'til at least 500 miles have been put on a new set of rings.
Let's see what happens in a few hundred miles, a compression test to check for broken rings wouldn't hurt, but if it seems to be working fine. Break in is very dependent on ring material and honing, not everything is good right out of the box.
I also think that 200 miles is too long for it to still smoke, however since it seems to be improving with riding I would be inclined to run it for a bit longer and see if the problem resolves itself. The compression piston rings are marked 'top' and must go the correct way up as they are slightly tapered.
My understanding concerning break-in is that these motors need a non-detergent motor oil to help the rings properly bed-in. Friction modifiers in modern detergent oils are great for extending the service life of many engines, but work against you when breaking the engine in, as they don't allow the rings to get hot enough to properly seal.

I would replace the Castrol GTX with Aeroshell 100, and run the bike. Load the engine, get it up to operating temperature, run through the gears, vary engine speed, up to maybe 5000 RPM.

Once you the 500 mile mark, change to your standard oil, check all the torque settings, adjust valves, chains, and carbs, and ride the pee out of it.
As has been said previously on this forum, these were a sports type motor,give it the odd good wind up to 5-6000,dont hold it there,but accelerate hard out of corners and enjoy the power,use the gear box, it should :roll: run in on gtx,if it has no faults, now go to garage,get large hammer and cheap hone, take it out to foot path and beat the crap out of it in front of wife, kids and neighbors :wink: :wink:
I read in the manual that if you're de-cokeing the piston crowns & de-coke slightly over the edge between crown & skirt, removeing the carbon here will make the smoking heavier untill this area re-carbonises again
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