The BSA A7-A10 Forum
Technical (Descriptive Topic Titles - Stay on Topic) => A7 & A10 Engine => Topic started by: anjimehra on 12.11. 2009 08:40
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Hi
Back again !!
How tight a fit should the inner race of the roller brg, drive side, be on the crank pin. I remember from years back when I worked on a Flash , the fit was quite tight & I had to press the race out.
However, on the current restoration, the fit is more of a sliding fit with a little tapping to start the process. Will this suffice or can anyone suggest a remedy as it is impossible to replace the crank here in India. Will a coating of Loctite ( 243 ) solve the problem.
Another query is that sometime in the dim distant past some mechanic had forgotten to replace the washer between the timing pinion on the crank & the worm drive for the oil pump. Can anyone please give me the dimensions so that I can make one. Iam assuming that if I dont get the thickness right, the oil pump gears wont mesh correctly?
Thanks & ride carefully
Anji
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G'day Anji,
it should be a tight fit but if it's not too loose loctite will do the trick. At least shimming the crank will be easier. The washer is available from most classic bike suppliers. My '51 ran for years without one. I have one ready to go in next time the cover is off. Can't lay my hand on it right now but think it's about 1mm thick.
Cheers
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Anji,
Loctite 243 would NOT be my choice, one of the bearing locking compounds would be, usually green in colour, designed specifically for the job.
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HI josh & "muskrat",
Thanks for the quick feed back. I intend to pickup some Loctite No 641, which the loctite guy tells me is the right compound for locking in bearings.
Will try a 1 mm washer tomorrow & see if it centralises the pump drive worm wheel.
Shall keep you posted on any other developments. This bike was badly butchered when I bought it for Rs 5000 in 1989 as a non runner for my sons 18th birthday. We got it going & he thrashed her for 5 years till it caught fire & was left out in the Bombay monsoons for 15 years. We had to break the pistons , almost, to get them out. How do I post some photos of her ?
Take care & many thanks
Anji
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Posting photos is reasonably easy:
1) find some where to host your photos, I use www.photobucket.com , its free.
Start an account and up load your photos.
2) post on here press the "Insert Image" button in the window above.
3 img] [/img this will appear, insert the direct link to the photo like this:
img]insert address here[/img
Done.
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Anji, you're lucky being able to fix it so easily. I pulled my A10 apart yesterday and the roller bearing fell off the crankshaft journal. I took the bottom half of the engine up to SRM today for them to sleeve and grind the journal to size. The bearing was also eating into the end face of the crank shaft! At least it's in good hands now.
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Hi there Muskrat
I did a mock assembly of the timing side & tried a 1mm washer between the timing pinion & the worm, but it didnt seem to work. I ultimately ended up using a 2.5 mm washer which gave the right amount of backlash, or so I think. What am i doing wrong
take care
Anji
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G'day Anji,
the back lash is due to worn worm. By increasing the thickness of the washer you have moved it to a less worn section of the worm. Should be OK if things don't bind up
Cheers
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Hi Muskrat
Youre absolutely correct as the gears are slightly worn & probably meshing at a different point, therefore the bigger gap. Thanks a million. Have you seen the photos of the Flash pre restoration. I think they are psoted on My pictures, friends ??
Take care
Anji