Author Topic: bearing / crank / case assembly , seal fitment (yamaha )  (Read 1309 times)

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lms6201

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thanks to all helpful bits so far , i,ve done this assembly many times , but i,d like to see if there are better ways , , is it better to fit bearings to cases then fit the shaft ? the yams i,ve had to disasemble have mostly been for  tranny issues and when the bearing is tite on the crank and doesn,t need replacement i can,t see the point of going through the trauma of getting it off ,   how tite should they be ?  all the bultaco,s i,ve rebuilt , the bearing / shaft fit is a lot less tight  , also  yamaha seals go castelation,s in , as far as i can tell from diagrams ( i have found them in some of my machines the other way round ) any confirmation ? the heavier seal lip would be inside ? tia

Offline holeshot buddy

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Re: bearing / crank / case assembly , seal fitment (yamaha )
« Reply #1 on: May 28, 2009, 08:06:13 PM »
seals go castelation inwards
i usually install bearings in the case first
never have problems ;)
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Offline gorby

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Re: bearing / crank / case assembly , seal fitment (yamaha )
« Reply #2 on: May 28, 2009, 08:25:33 PM »
cold bearings from the fridge into heatgun warmed cases,then cool crank into warmed bearings :)

Offline holeshot buddy

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Re: bearing / crank / case assembly , seal fitment (yamaha )
« Reply #3 on: May 28, 2009, 08:29:44 PM »
WITH COLD BEER IN ONE HAND
AND WARM WOMAN IN THE OTHER ;D ;D

REMEMBER IMS MAKE SHAW TOUNGE IS POINTING RIGHT WAY :P
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lms6201

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Re: bearing / crank / case assembly , seal fitment (yamaha )
« Reply #4 on: May 28, 2009, 09:50:26 PM »
thanks for the seal confirmation , try and get this crank looked at tomorrow ,

Offline vandy010

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Re: bearing / crank / case assembly , seal fitment (yamaha )
« Reply #5 on: May 29, 2009, 12:33:16 AM »
i usually fit the flywheel side bearing to the crank first, then drop that assembly into the left side case.
i fit the seals after the bearings are in.
to remove the bearing off the crankshaft, i take the crank assembly {with old bearing still mounted} down the the bike shop and have them remove it for me. i just find it easier that way.
i point my tongue to the left when working on the left side case and to the right for the right side case also and have never had a problem in doing so.
some other "motors" will require the tongue facing forward.......
but thats another story.....
"flat bickie"