A65 Primary chaincase

[pockets]

Have to replace gasket on chaincase no wonder it leaks , is this  normal to have so   small an amount of mating surface on the bottom part of gasket seam where i presume the oil drain allen bolt sits .

[pockets]

https://flic.kr/p/2nmr2RP

[DAVE BRADY]

Hi Pockets,

Quite normal on those cases.  Use a good quality gasket and it should not leak.

Dave.

[pockets]

Got one from srm along with some rtv  silicone sealent , they dont stock Wellseal  any more something to do with being toxic or somesuch . any tips on using the granville sealent . gunna use some alchohol to clean the surfaces , can see why old brithish bikes have a habit of leaking oil going on the design of the drain plug on the chaincase , shaving away the material in that locationto aid oil outlet  isnt the best idea. Can people open the image from the flickr  link i supplied?

[DAVE BRADY]

Hi,

Yes, I opened the image Ok but you can post on the Forum if the images are not too big.
I use Hylomar on the case only and 'stick' the gasket to it then leave it for a few minutes to settle (it does not set hard).  Coat the other surface of the gasket with plenty grease. I use a high temp. moly grease.  It may look like it soaks in so apply a bit more if needed.  The idea of the grease is that you can take the case off and the gasket remains intact to be used several times.  Just smear on a bit more grease each time.
Also, do not over tighten the screws.

Dave.

[cdsdorset]

Forget the gasket  just use 3 bond.

[pockets]

thanks Dave  , may give the grease a go just dont want it to leak again , the gasket is green one side and blue the other , wondering which way to put it, but may find it only fits one way . the  allen bolts seem quite short on some of the threads and a little loose in the thread ,  a few of them are a different allan key size  {slightly smaller} ,  not sure what's going on there , may check that they are gunna be ok before proceeding .

[pockets]

Have purchased the gasket and sealer  already  so going to use it.

[spaceman]

thanks Dave  , may give the grease a go just dont want it to leak again , the gasket is green one side and blue the other , wondering which way to put it, but may find it only fits one way . the  allen bolts seem quite short on some of the threads and a little loose in the thread ,  a few of them are a different allan key size  {slightly smaller} ,  not sure what's going on there , may check that they are gunna be ok before proceeding .

I would definitely check the length of the screws against the parts book to make sure you have got the correct lengths and to also check you are using the right screw for each hole by dry fitting the cover and checking the depth to the bottom of the threaded hole. If you use the wrong screw, it is very easy to strip the thread.

[DAVE BRADY]

Hi,

Ditto what Spaceman said about the screws.  Some of the replacement 'Allen' type sets are not all of the correct length and some have a poor quality thread.  It is worth having a good poke in to the holes as years of gunge and bits of sealant build up at the bottom.  Some brake cleaner and an air line are a great help.  For persistent crud a tap can be run down the thread to get it nice and clean  You may find another 1/4" of thread is available and the true depth of the holes can be used.  The more thread that is engaged the more secure the screw.  When tightening with an Allen key only use the key (standard length) itself as no extra leverage is necessary.
The screws that are bit loose and need a smaller Allen key are a bit suspect. 

Dave.

[cdsdorset]

To make sure the bottomoc the hole is clear of gasket goo wind a woodscrew around in it.

[pockets]

Thanks for the tips , ye was gunna closer inspect all the bolts before reusing by seing how far they all protude throught the cover , anybody now the correct lenghts and size /pitch and good  supplier , the ones with it may just be bad  aftermarket stainless replacements.

[pockets]

Downloaded a parts catalogue but the part number doesn't come up with a search, and dimensions aern't shown so not a lot of info to be gleened.

[chaz]

pick the year of the bike from the options
https://draganfly.co.uk/product-category/bsa/sparesparts-for-bsa-a50-a65/

they usually have threads and lengths listed otherwise search places like
https://www.baxtercycle.com/parts/parts-books-online/bsa/and use their search facility

eg for 1966 get the part number, there are a few different lengths, then go onto their shop page and enter.

https://www.baxtercycle.com/product/76-0546/
https://www.baxtercycle.com/product/70-8168/   note on this part number, they give 2 or 3 optional numbers

[spaceman]

What year is the A65?