Hi, I fitted new pistons ,rings and had the cylinders relined. I checked the valve movement before assembly and it looked fine. The bike starts but it runs uneven and is smoking badly from the left cylinder.There is a good spark .The right cylinder appears to run and the plug looks normal.The left cylinder plug is very wet however. Any ideas.
Joined: Jan 2006
Go for a ride and get the rings seated. Put several hundred miles in the bike. If they're seated properly and the bike still smokes, then you can move on to look at other things. How long have you had the bike?
Joined: Sep 2002 Posts: 7,812Alex
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Joined: Sep 2002
I assume you're burning oil (grey/white smoke) and the offending plug is wet with oil? Couple of possibilities in order of likelihood: Broken oil ring on installation, badly made oil ring not seated, inadequate clearance and smeared piston on startup, assembly lube somehow got on bores preventing rings from seating.
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Joined: Jan 2006
Originally Posted By: Swan
Do you park your bike on a side stand or center stand? Believe it or not, parking on a side stand can cause oil to drain and accumulate on your left side causing oil fouling and smoke on start up.
Jon-I'd have to disagree with that statement-at least as far as my Lightning's concerned. I thought that was the case until I took my head to Alex's and he pulled the broken guide. If the oil drain holes aren't clogged and the oil is allowed to drain properly, and the guides are sealed tightly in the head (and more importantly aren't broken), I don't see any reason sitting on the side stand would allow oil into the left cylinder. However, that's just my observation on my one bike...not sure about an A10.
Joined: Jan 2006
Derrick-it is either getting in from the oil ring or the head. Not sure how long you've had the bike or of it's history, but if it was running fine before and the only thing you've done is resleeve the cylinder, I'd take Alex's advice and check the left side rings.
I striped it down and rings look fine. There was a lot of oil on both piston crowns.A oil ring upside down not sure how .They look the same ? I had the valves out and re grinded them without a problem.I will check the left inlet anyhow. What interesting is that an oil ring originally broke and there was no smoke!
The rings are new .The valve collars checked and are ok.Wet sumping was not a problem before .I will drain it though. The timing case is off as I was doing the timing . I just did a few quick test starts .
Is your second ring without a taper ? If it has a taper, and is upside down it will pump oil into left cylinder. But reading that both pistons crown are covered with oil I suspect valves. Did you check your valve / guide clearances during regrinding ? If your valves went into guides like a stone in the well, the clearances were too big.
Last question - when was a bike smoking, on acceleration or during deceleration ?
Take the rings off the piston and put them in the cylinder and check the end gap. Make sure they were all installed correctly. If I remember correctly rings have a faint stamp or mark next to the gap. They should be installed stamp facing up toward the cylinder head. If you got a top ring installed up side down then it will scrape oil in the wrong direction? I may be wrong about this. It's been a while.
Also check the valve guides and the valves. If the clearence between the two is too large it can suck oil from the cylinder head. I had this problem with my T-bolt after its rebuild. I ended up rebuilding the head as well. Also the Emgo rings got changed out for Hepolites.
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The piston and rings were supplied by SRM .The pistons are from Taiwan and the rings Italian.The Taiwan rings are not good. I cannot see any markings on the rings but they could be in wrong way up.I will check. The valve clearance is ok.
The A10 GPM Italian pistons we have in stock have grey cast iron rings with no markings as to top. They also do not have a chamfer on the top back edge to indicate top.
So here's the real story: We have dealers that have had good luck with Emgo - Taiwan, GPM Italian, what passes today as Hepolite, Hastings and Deves rings.
We have dealers that have had nothing but bad luck with Emgo - Taiwan, GPM Italian, what passes today as Hepolite, Hastings and Deves rings.
We have dealers who never have any problems with rings and we have dealers that consistently have problems with rings. ______________________ Matching the cylinder bore surface finish to the rings being used, and how carefully you remove and install the rings, is every bit as important, IMHO more, than the ring gap.
Grey cast iron rings are really designed to be used with cylinder bores that are held to a tolerance .0005" to .001. and a maximum grit stone of 220. Most of the dealers I know who are successful at getting the rings to seat use 180 grit stones. This means that there can be as much taper top to bottom of .001 inch and out of round .001".
Typically it is hard to get these old cylinders to a tolerance close to .0005". It is not uncommon for a cylinder to warp in the hours after it was bored. The technician might have had the cylinder perfectly round with no taper from top to bottom (or close) but let the cylinder set over night and measure it again. Thus a lot of technicians bore the cylinder one day and finish hone it the next. This gives the cylinder a chance to stabilize before you hone it. Yes, when you remove the hardened skin that is the cylinder bore it releases tensions that have built up in the cylinder over the years. ------------------- Steel and Ductile Iron rings are designed to be used in a cylinder that is held to a tolerance of .0002" or less. These cylinders are typically finished with a stone with a 280 grit of finer. A cylinder must be designed from the git-go to be able to attain, and hold these kinds of tolerances. Because the cylinder is nearly perfectly round after honing they do not need to be finished honed (like our old hunks of iron we call cylinders) by the rings in service. The rings are also lapped perfectly round during production and little, if any "ring Break-in" is required.
I found the problem.The centre compression ring has a step which must face down.Pity SRM did not send instructions with the rings . The Haynes manual has nothing about fitting them. What's the next problem....
Historically AE top two rings for these motorcycles are taper faced and always marked as to which side is the top. Even the latest iteration of AE/Federal Mogul brand made by Goetze made in Germany have "top" on the two compression rings.
What you are describing does not sound like AE rings to me.