Wildguzzi.com
General Category => General Discussion => Topic started by: brider on October 12, 2017, 03:29:43 PM
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I searched under "valve guide seals" and got a bunch of hits for Griso problems?????!!!!
I just changed the oil, did NOT notice any smokescreens prior, and now on startup, my left cyl smokes like crazy. Coincidence with the oil change, or a result of?
My gut says coincidence, but that would still mean worn valve guides or just worn seal(s).....on one side only. LH probably will follow any day now?
Engine only has 44k miles on it, so I'm kinda surprised. Would this be expected at those miles? Are guides/seals a machine-shop task, or garage-bench?
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No seals on the 2V motors until the very last run in 2007/8. If it's happened suddenly the obvious source, especially if it lasts for more than a few seconds after start up, is a busted oil control ring unless it's been seized, (Unlikely.).
On the pushrod motors the valves can get as sloppy as anything in the guides and they will only tend to smoke for a minute or so on start up after sitting. Then the smoke will clear and you'd hardly know anything was amiss. If the guide is loose in the head it will produce more persistent smoke but again that is very rare.
Only way to find out is to take a look.
Pete
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With 44K miles,if you have had some blow by, in addition to a bit of wear to the valve guides, the oil control rings may be gummed up, and not working freely in their respective grooves. I would pull the plugs and add a couple ounces of marvel mystery oil, or sea foam to each cylinder, let it sit overnight, then crank the motor over with a rag over the plug holes, you may be surprised, with the gunk that comes out. then run the motor with some seafoam in the gas, and see what happens. It wont hurt anything, and may help!
Rick.
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OK, so no seals, and either I got the cylinder wrong the first time I looked, or the problem now surfaced in the left cylinder. Lasts for maybe 15 sec.
Looks like another aspect to my winter maintenance regimen. If it IS a broken ring, how dangerous is it to ride it like that? Likely to damage a cylinder wall?
Thanks!
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I had a customers do that at 80Kmi on a Cali2, pull it apart to find the ring gaps were all lined up. Never been apart or puff oil beforehand.
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15 seconds is a long time for a valve guide. . Time for a leak down to find out what is going on.
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What color is the smoke?
Does it happen every time you start it, or only cold/hot/warm/?
Are there any other symptoms besides smoke? Clatter, vibration? poor running?
Do you park on the sidestand, and have you double-checked your oil level?
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15 seconds is a long time for a valve guide. . Time for a leak down to find out what is going on.
Yeah , or considering it only takes a leisurely hour to take a peek inside ...
Is there any chance the engine is overfilled ?
Dusty
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What color is the smoke?
Does it happen every time you start it, or only cold/hot/warm/?
Are there any other symptoms besides smoke? Clatter, vibration? poor running?
Do you park on the sidestand, and have you double-checked your oil level?
Update: No other symptoms, bike is running like it always has, no excessive clatter, starts easily and idles smoothly. Checked oil level (I just changed it) after 20-mi ride, tip-top, no drips or leaks (fixed all those last winter. I smile every day because a huge Harley road pig I park next to every day has a constellation of oil drips on the pavement beneath it).
HOWEVER, just this morning I fired it up (ambient temp high 40's) and watched CLOSELY to determine which cyl was spewing forth.......and NO CLOUD AT ALL.
Just yesterday @ 5pm I left work and witnessed an oil cloud that was NOT my imagination. And 15 sec was a bit of an over-estimate, looking at my watch now, 8-10 sec was more like it.
I will assess it again when I start it up to go home. I like the ring-gap-lining-up idea, but then again, what are the chances, and what about those ring-groove "stops" that are supposed to keep the rings in position? What happens to them?
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I will assess it again when I start it up to go home. I like the ring-gap-lining-up idea, but then again, what are the chances, and what about those ring-groove "stops" that are supposed to keep the rings in position? What happens to them?
There are no "stops" on Guzzi big twin pistons. Normally, only two-strokes have "stops" to keep rings in a certain position.
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My R75 sometimes smokes at start up. I think it's due to bad valve guides. When I first got the bike, it smoked pretty bad at start up, but after about a year, it's less.
Good luck,
Tom
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My R75 sometimes smokes at start up. I think it's due to bad valve guides. When I first got the bike, it smoked pretty bad at start up, but after about a year, it's less.
Good luck,
Tom
Are you leaving it on the sidestand ?
Dusty
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Marvel Mystery Oil to loosen the rings. My SP is/was smoking on the left side. It currently has 46K miles on it after this last trip. It was smoking on the left cylinder too. Not after a bunch of tanks of gas with MMO.
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Couple of questions? Are you running the stock air box and breather system? Has the motor got a sump extension? If it doesn't are you running the oil at the 'Full' mark on the dipstick and if to does have you got a longer stick and dropped the level?
Pete
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Sounds to me you are seeing the classic signs of worn valve guides. My SPIII did exactly this and it seemed to be bad one day and then not the next. Pull the plugs and see which is oily, it'll be obvious, they don't lie. Pull the corresponding carb and intake runner off and check for oil on the valve stem. Don't forget to rotate the engine so the valve opens and closes so you can really see the oil. K line is the way to go for the repair.
I also replaced the rings at the same time as the end gaps were huge, if I remember more than 1.5mm :shocked: It seriously is an easy procedure to do. Running in after this took a couple thousand K's but today zero oil consumption and no smoke :thumb:
Good luck with it!
Adam
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Did you remove the old oil before adding the new?
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Did you remove the old oil before adding the new?
Ha! Good one! But to address Pete's questions: Stock air box, no sump spacer, stock dipstick, oil level is near top, but I always ran it mid-level or near the top, even before the recent oil change. Didn't seem to burn any oil, or drip oil, so the oil level never really dropped.
My first suspicion was the valve seals (which I learned don't exist), so valve guides don't surprise me, except that the mileage seems kinda low...never read of worn guides as a standard maintenance item on a 44k square-fin. I'll keep a closer eye on it this next week, but I guess there's nothing else to do but pull it apart.
What's this K Line thing?
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K-Line valve guides are a bronze tube that are driven into your existing valve guide after it is cut .030 larger with a special cutter/reamer, the bronze sleeve is then sized with a swage to the correct size . usually you can run tighter stem to guide clearances due to the fact that it is now possible, this also helps the valve face and seat maintain their angles better which leads to prolonged sealing. I have used K-Line guides in all manner of engines since about 1982, they are durable and a cost effective repair, the real plus side is that you do not disturb the original guide and thus the guide is more concentric to the seat, therefore less grinding is required to effect a correct seal. not to mention your guide if removed, can result in a number of horrible consequences down the road. DonG
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Around here they look at you funny if you ask a machine shop about K-Lining and I never understood why, its a good repair and one I prefer over punching out and replacing a guide.
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Pardon my ignorance folks, but can valve guides , in a square head big blockbe replaced by the average "home mechanic" with a benchtop press, or does it have to be done by a machine shop?
I am thinking of my Lemans IV. Its fine now, but I have read that those motors a a bit tough on valve guides, and Im sure I will have to replace them or do the K line thing sometime in the future.
Thanks,
Rick.
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It takes more than a press. You'd pay more to tool up for the procedure than it would cost to have it done by a shop. And replacing/centering/setting length/reaming on the guide is just one small part of the procedure. It still needs to be concentric to the valve seat, and the valve and seat need to be recut for center, seal, and depth. Then you need to set the spring height and tension . . . . So you need the tools and skills to do all of that.
K-lining is more complicated.
Of course others will tell you that it doesn't require a press at all -- just have someone hold your beer while you drive out the old guide with an air hammer and run the new on in the same way. If the valve doesn't bind in the guide it's good, and who cares about concentricity, seat angles and depth, anyway?
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Are you leaving it on the sidestand ?
Dusty
Yes side stand, yes I know.
When I first got that bike it had sat for quite some time. For about as year it put out a nice smoke screen, it gradually went away and now it normally starts with no smoke.
To OP,
So to be clear, all was fine before the change. Drained the old oil and then filled to just below the full mark and now it smokes??
Tom
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My lemans before its rebuild, had shot valves,valve guides, rings worn, 150 psi compression.
It wouldnt idle well, was low down on power funnily enought.
Despite all that the one thing it DIDNT do was blow smoke.
What would I do?
Compression and leak down tests, flangemans advice is worth a look as is anything the rubber chicken wrangler comes up with (P.R).
You did use the same make and weight of oil?
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It takes more than a press. You'd pay more to tool up for the procedure than it would cost to have it done by a shop. And replacing/centering/setting length/reaming on the guide is just one small part of the procedure. It still needs to be concentric to the valve seat, and the valve and seat need to be recut for center, seal, and depth. Then you need to set the spring height and tension . . . . So you need the tools and skills to do all of that.
K-lining is more complicated.
Of course others will tell you that it doesn't require a press at all -- just have someone hold your beer while you drive out the old guide with an air hammer and run the new on in the same way. If the valve doesn't bind in the guide it's good, and who cares about concentricity, seat angles and depth, anyway?
Generally on aluminum bike heads, you cut down the spring side of the guide, heat the heat to about 210 degrees, and drive out the guides with a proper drift and hammer into the combustion chamber to avoid carbon on the guide from broaching the guide bore ..You can also use a press...Yes, always check the valve to seat and most always you'll need to cut the seats a bit....
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To OP,
So to be clear, all was fine before the change. Drained the old oil and then filled to just below the full mark and now it smokes??
Tom
Yes, all was fine before, same oil as before, same oil level as before, although that isn't something I paid that close attention to as long as the level was 1/2-way or higher between the marks without over-filling.
Yesterday when leaving work: Smoke. This morning when leaving home: No smoke detected. At this point it is NOT consistent. Keeping an eye on oil level, but this is one of those issues I'm going to live with until I can take the bike off the road. Maybe this winter. Starting, running, idling same as always, so I am not compelled to pull the top ends yet.
Thanks all! Once again, I learned a few things!
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There are no "stops" on Guzzi big twin pistons. Normally, only two-strokes have "stops" to keep rings in a certain position.
Charlie: I ran into a post by you from a couple of years ago regarding a guy with "pinging" problems on his Convert. You mentioned that worn valve guides can dump excess oil into the cyl and lower the octane of the fuel, causing pinging:
http://wildguzzi.com/forum/index.php?topic=76891.0
As it happens, I've narrowed the billows of smoke to my LEFT cyl, and it's the LEFT cyl that has been pinging under moderate/heavy load since about the time the smoking started!!!!
So I'll bet it IS worn guides (at least on my left cyl), as if the billows of smoke wasn't a big enough clue!
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Could this be a breather problem ?
Dusty
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I'm not sure what temperature you're riding in but I notice my heads starts creating "mayo" when it gets close to 10C where I live. It causes the breather return hose to work less efficient. Perhaps it could cause excess oil left in the heads too while parked? And with excess oil, more oil to drip down from the valve guides?
I have swapped the head covers around so the hose now leaves the back of the covers instead of the front, it makes the hose stay warmer and less mayo.. I think.
I know it's not resolving the root cause (worn valve guides) but at least it could explain why you suddenly see this smoke if the temperature have dropped
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don't get wrapped around the axel too soon on this, its probly a breather problem. look inside the airbox for oil. maybe that's where it is going into the cylinder. I take the line that drains into the airbox and just dump it overboard or into a catch bottle where you can monitor the quantity of oil coming out. apologies if someone already said this
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don't get wrapped around the axel too soon on this, its probly a breather problem. look inside the airbox for oil. maybe that's where it is going into the cylinder. I take the line that drains into the airbox and just dump it overboard or into a catch bottle where you can monitor the quantity of oil coming out. apologies if someone already said this
This (and the previous post by Dusty) is the first mention of a breather problem, and by that I assume excess case pressure blowing oil out the breather into the intake?
I can't envision the Cal 2 breather system from memory, but I recall it was/is a bee-otch to route the rubber hoses, and the airbox is a massive PIA to access, but I guess I'll consider this before I pull the heads to have them re-built.
I haven't searched this forum for "leakdown test" yet, but would a leakdown test confirm bad valve guides? Don't see how that's possible if the valves are seated, how would that have any bearing on the guide condition?
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Leak down test will only show ring and valve seal condition. DonG
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Suck a cup of oil out and ride it a few days to clear the air box. Might not work but cheap to try!!!!!!!
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I could be wrong but from my own experience, the return hose from the head covers to the breather box were completely clogged with "oil mayo" last autumn and I burned oil. I could not blow through it with my mouth but when I put compressed air into it, the plug came out. Once they were cleaned, my oil consumption almost disappeared.
I would suggest you to remove the return hose from the heads and blow them clean with compressed air. At least it doesn't hurt.