Belt and braces cant be a bad thing do everything 1608 suggests, then very lightly smear the drive side of the crankcase halves with Welseal or my chosen poison Hylomar and that means very lightly.
Then using cotton thread lightly impregnate that with Welseal or Hylomar and lay it into the already applied seal inside the stud holes but all around the filter tunnel and the distribution chest, but do not cross the thread over itself.
Then very lightly smear the timing half of the crankcase with the sealant.
Assemble as described by by 1608. You will be surprised how much sealant maybe squeezed out, but remember it will happen inside as well as out, and that's why you must not use it in excess, as the bits inside could easily block an internal oil way.
Be you own judge of if you think you have overdone things and if necessary start all over again.
650 crankcase joint...
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Eric
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Groily
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650 crankcase joint...
Well, they were designed to have the little wee one round the filter chamber that Don mentioned, and as, again, Alan Biscuit Jacobs said - 'why have one bit of the cases a few thou proud of the rest'?! It is indeed a finnicky business but there's always more than one way to skin a feline.
I never use such things on other engines either.
Another possible consequence of not carefully doing one or other of the things here described is the risk of fatiguing and even eventually busting one or more of the three blind screws in the crankcase through over-tightening. Been there too, and they're a nasty one to sort out.
Each to his own I guess, whatever works . . .
I find a simple paper gasket too thin to get the dynamo to pull up home into the rear of the timing side case, so I make laminated ones of several layers of paper with jointing compound between and no problems in really loadsamiles.
And for the pressed steel primary, I use a ring of gasket paper pinched between the two halves with a good squidge of silicon gunge, then the usual bits - and not a single drip.
That just leaves a tiny weep from the gearchange indicator shaft on the Burman, and a small drip from the alloy chaincases on my AMC-equipped one, and that's the sum leak total on my pair of twins. For the moment, of course.
I never use such things on other engines either.
Another possible consequence of not carefully doing one or other of the things here described is the risk of fatiguing and even eventually busting one or more of the three blind screws in the crankcase through over-tightening. Been there too, and they're a nasty one to sort out.
Each to his own I guess, whatever works . . .
I find a simple paper gasket too thin to get the dynamo to pull up home into the rear of the timing side case, so I make laminated ones of several layers of paper with jointing compound between and no problems in really loadsamiles.
And for the pressed steel primary, I use a ring of gasket paper pinched between the two halves with a good squidge of silicon gunge, then the usual bits - and not a single drip.
That just leaves a tiny weep from the gearchange indicator shaft on the Burman, and a small drip from the alloy chaincases on my AMC-equipped one, and that's the sum leak total on my pair of twins. For the moment, of course.
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Duncan
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- Location: HAMPSHIRE UK
650 crankcase joint...
As advocated by Alan I am a firm believer in making a gasket for the twins crankcase joint, I used 0.5mm Klingersil C4400 with a smear of Wellseal on final assembly, tearing and movement is not a problem with this material.
As advised earlier the original design requiring the insertion of the filter tunnel gasket in the middle of otherwise flat jointing faces can not be considered best practice, can you name any other flat joint faces you would contemplate making with less than half a gasket? Would you try it on your gearbox cover next time?
When you look closely at the minimal amount metal around the rocker feed gallery and then ponder the internal oil pressure and the close proximity to the filter tunnel gasket you can quickly understand why so many owners repeatedly remake the barrel base gasket joint without fully understanding where the oil is issuing from.
As advised earlier the original design requiring the insertion of the filter tunnel gasket in the middle of otherwise flat jointing faces can not be considered best practice, can you name any other flat joint faces you would contemplate making with less than half a gasket? Would you try it on your gearbox cover next time?
When you look closely at the minimal amount metal around the rocker feed gallery and then ponder the internal oil pressure and the close proximity to the filter tunnel gasket you can quickly understand why so many owners repeatedly remake the barrel base gasket joint without fully understanding where the oil is issuing from.