The BSA A7-A10 Forum
Technical (Descriptive Topic Titles - Stay on Topic) => A7 & A10 Engine => Topic started by: ShaunMac on 12.04. 2014 16:33
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I know I'm going to look daft posting this but just took the timing cover off due to magneto removal and I've noticed the timing marks don't line up. If I pull the idler gear out just so the teeth disengage and rotate it then they line up.
Am I doing the right thing? *sad2*
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in a word yes, and you will have spotted one set of marks are dots and the other set dash's they must match dot to dot dash to dash (sorry if that seems obvious)
The marks only line up once every 80 odd revolutions or 70 can't quite remember, but it matters not, idlers are designed that way so that the same teeth are not meshed every time.
And no questions are deemed daft here (some of my answers maybe) Knowledge is nothing until it's shared
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Thanks Bill.
I can strip Diesel engines with my eyes shut but the sentimental value of this engine is making me ask lots of questions. All I can say is this forum is a God send!
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Oh right - sorry I remember now it's your dads bike, nice project I'll bet
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There's two things that have really got to me on this rebuild...the person who originally built this bike for my dad as whoever it was has cut a lot of corners and also my brother who stored it for 10 years and just started it up every now and then for a run down the road and killed the engine.
The connection I have with this bike is more than you can imagine and even though I work everyday with all types of vehicles the reassurance from everyone on here helps me so much.
I know that the day she fires up there'll be a big smile from me and from above.
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So, Shaun, I take it the bike was not running with the idler marks misaligned? The marks on the idler are really just a convenience to make sure the dot on the crank pinion and the dash on the cam gear simultaneously point at the exact center of the idler spindle/bush. As long as they do, lining up the marks really wouldn't matter. Now, no one here, including myself, would recommend ignoring the marks, but I was just wondering if the previous builder just got lucky with the cam and crank position.
Richard L.
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At risk of stating the obvious *conf*, The crank dot and cam marks should be in 'alignment' position every two revolutions, irrespective of where the idler marks are, and said idler should be able to be removed and replaced with all marks in correct alignment....someone tell me if I'm wrong, as this is an easy check/shortcut....???
anybody have the right change for two bob?
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dots on crank.... dashes on cam... *smile*
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The idler was about 6 teeth out. Moved it round and it lines up dot - dot & dash - dash.
Have to say I'm loving working on the bike, just wish I had a bit more knowledge on them.
Every days a school day!
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and said idler should be able to be removed and replaced with all marks in correct alignment
of course Dutch, however with it off it's so easy to move something and forget - must have been done hundreds of times (even hundreds of times plus one ;))
and will four tanners do *smile*
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Posh Sod Wozza, showing of your SRM pump, *grins* very clean though ,cheers Bobh
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Posh Sod Wozza, showing of your SRM pump, *grins* very clean though ,cheers Bobh
Not Posh Bob.... more like a LUCKY BUGGER...
Thanks to mark from this site who came to my rescue ... & sold me it for MUCH less than it cost him. *wink2*
what I like about this site & our members... is their generosity & willingness to help out when they can. *beer*
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I'm hearing you there Bill- even soon's idler comes out, all of a sudden one can't be certain that either mark didn't move just that little bit under (valve) spring pressure or compression ( *ex*was that my imagination *????*, ), unless one was to use temporary marks with marker pen- but unless we're lucky enough the marks are close enough to just spin it a little bit to realign all, I think what I also meant was that if the idler is just replaced as-is, it should takes less than two crank rev.s to bring the Crank and Cam to the right spot, and take the idler out and spin to the marks to check...(better than trying to do eighty or so, as I've tried to do in the past- till I realised the idler had different # of teeth)?
hope all that makes sense..?? and does it win anything for 'long sentence'- tried to break it up...!
...and will four tanners do *smile*
...four would be fine, but threes' ok take a tip-ple *beer*