The BSA A7-A10 Forum
Technical (Descriptive Topic Titles - Stay on Topic) => A7 & A10 Engine => Topic started by: TonUpTrav on 13.05. 2014 19:46
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I got my 59 Super Rocket out today and drained the oil from the sump. The magnetic sump plug had more than the usual metal shavings on it. I drained and added oil. It's always had the british bike clatter since I picked it up last year. However, it seemed to have a bit more clatter than I remember since I last road it (or so it seems compared to the 54 Golden Flash I picked up a week ago). Obviously increased shavings means there is increased wear on something in the motor but is it something I need to be weary of and stop riding it? I'd hate to destroy the motor! The motor has right at 900 miles on it since it was rebuilt about 15 years ago.
Thanks,
Travis
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Shavings ! Travis is that shavings as in slivers of metal like very small finger nail clippings - that is not good
I would say normal stuff from a magnetic sump plug would be like a soft grey paste but not anything that would be recognisable as a piece of metal
which of the above best describe your shavings
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Largest being a bit smaller than the tip of a ball point pen maybe.
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Maybe small flakes is a better description.
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metal shaving?...crank shims maybe?
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That was my 1st thought too Rob.
Trav, pop the primary cover off, check the crank nut hasn't come loose and feel for end float. Also drop the sump plate off and see whats on the screen.
Cheers
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Ditto. Can't say this is Travis' problem, but probably the 1st thing to check. Only magnetic pieces (apart from very fine stuff when running in) I've seen here are from destroyed endfloat shims, innerrace drive side not tight enough on shaft. I need to get some metal 'build-up' to secure it, which will hopefully lock any shims properly. And I learned to find one shim of the right thickness instead of many flimsy ones.
Found an old shim from my engine, see picture. On the worn part looks like half the original thickness is gone. Another had disintegrated.
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How difficult is it to replace the shims if they are found to be the
problem?
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Full engine dismantle Trav. The shims are located between the crank and the bearing on the left side.
If your magnetic plug is picking up anything more than a grey paste then the motor needs to come apart, things like this only get worse, not better and it is better to pull it apart and sort it than let it go bang.
Probably not what you wanted to hear.
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Taking the ultra positive view, could the oil tank have not been cleaned out properly from a prior blow up?
If so that might leave you looking for the source of clatter which could be minor like dynamo chain or tappets *lol* *good3*
Either way I would start looking for the source of clatter and be prepared for a strip down as per prior posts. *problem*
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Kiwi, whilst hateing to disagree , what you say is a possibility but to get to the sump plate that metal has gone through the system and must now be treated as dangerous until found to be otherwise. I've always worked on the basis that metal there means a strip down to find out where it's come from . imagine the consequesces of a further lump getting into a bearing . So although I'm always optimistic I'd only feel safe with a look inside , regards BobH
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Hi trav.
That,s bad luck, as stated before sounds like shims have broken up, relates also to increase in engine noise, no alternative but to strip engine, continue to run and costly damage will occur. Our worst nightmare.
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Heh Topdad/Bob its fine you disagree ;)
Filings from the oil tank would go through the pump and end up in the sludge trap, some I guess could go the other route and miss the bottom end and end up on the sump plate gauze.
Safest approach is to start stripping and clean the filings out of all the nooks and crannys.
Shims disintegrating has been mentioned here a few times, what is the root cause of shims failng? Is it the cush drive nut coming loose? Even for a short time? Is it possible to have incorrect parts that mean the bearing is not properly clamped?
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Hi Travis,
Have you checked the tappet clearances?
Lac of or low oil pressure (PRV not opening) leads to the cam being starved of oil, so the cam and followers wear
tappet clearance increases = clattery engine and debris in the sump
*sad2* *sad2* *sad2* *sad2* *sad2*
HTH
John
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Small bits like these?
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The horror!
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Charles,
No small bits like that! That makes me cringe just looking at the photo.
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So it sounds like it could be anything from not so bad to horrible! Would you guys suggest that I find a reputable bike mechanic in my area to check it out? I'd do it myself if I only
had more time in the day. Work is keeping me busy lately.
Thanks for the help,
Travis
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Trav,
Whereabouts are you located?
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I'm located in Eastern Indiana.
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Travis,
I'm a member of the Chicago Norton Owner's Club, for lack of a local BSA club (several member also own BSAs). Someone from the club let me know about Expert Cycle Works in Hobart, IN. I gave Bob Goodpastor at Expert a call regarding some parts and, though he didn't have those parts, it was an interesting conversation. I haven't actually done any business with Bob, but he seemed like someone I would be very comfortable trusting with engine work. Here is the link to the website:
http://expertmotorcycleworks.com/
Richard L.
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Had a chance to take the primary cap off the primary cover tonight. The chain was slapping around more than I would consider normal. How do you adjust the tensioner on a 59 A10? My BSA resto book speaks more on adjusting unit motors.
Travis
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Loosen the gearbox bolts and adjust with the draw bolt which is on the right engine plate. Don't forget to tighten the gearbox bolts.
Then adjust the rear chain.
Trev.
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As Trev says, and another tip. Adjust it till it's too tight and then use the draw bolt to push it back till the desired slack is achieved. This helps prevent the torque of the rear chain pulling the g/box back and tightening the primary chain.
Cheers
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I second Muscrat's advice, whats more when I did NOT use the draw bolt to put permanent forward pressure on the box the box moved and almost certainly was a contributor to an early failure of the gearbox mainshaft sleeve gear bushes *problem*
its very important not to over tighten the rear chain on these bikes as that can cause the box to move a NJ d over tighten the primary chain