Author Topic: Hey guys do you have to split the case to change crank seals?  (Read 7604 times)

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Offline cappra

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Re: Hey guys do you have to split the case to change crank seals?
« Reply #15 on: August 29, 2008, 03:14:53 pm »
I use the lapping compound you can buy at most automotive
supply houses.  It consists of two small tins, one course and one
fine compound,  put some on the crankshaft, mount the flywheel and turn it
by hand in one direction (without the flywheel key in place, of course)  After a couple of
minutes, remove flywheel and wipe all area's clean.  Then repeat with
the fine compound.  You should actually be able to feel the flywheel start to
"bite" on the shaft and see a dull looking area where the flywheel mounts.

All you are really doing is creating more surface area
for the flywheel to hold on to by smoothing down the uneven surface of the
shaft.  This is an old karting trick.  There was some classes that you were
not allowed to alter the timing, so the guy's would eliminate the flywheel key,
lap the shaft and then mount the flywheel in an advanced timing location for
better performance.

runutz698

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Re: Hey guys do you have to split the case to change crank seals?
« Reply #16 on: August 29, 2008, 03:59:31 pm »
Thanks Jared will do that on the monty and the IT400 I about to rebuild as it seems to make good sence. It is amazing if you do it you can mount the flywheel with no key and it will still stay in the right postion.

Offline mike1948

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Re: Hey guys do you have to split the case to change crank seals?
« Reply #17 on: August 29, 2008, 04:08:36 pm »
While we're on the subject of mag flywheels, I've been using a brutal outside puller to remove mine (sorry, VB ), and it's time I got the right one.  The bike is in the back of the shed at the moment - prospective buyers for the house wandering round, don't want them to find out I'm a motorbike hoon.  I don't remember if it has a thread of 30 or 33mm x 1.5mm.  You intelligent Montesa owners will know.

Offline cappra

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Re: Hey guys do you have to split the case to change crank seals?
« Reply #18 on: August 29, 2008, 04:22:08 pm »
Montesa motoplats (electronic) use the 27mm x1.25 puller.
Points models use the 30mm x 1.5 puller.

Offline Hoony

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Re: Hey guys do you have to split the case to change crank seals?
« Reply #19 on: August 29, 2008, 04:24:33 pm »
...... don't want them to find out I'm a motorbike hoon.  

Whats wrong with that?
Long time Honda Fan, but all bike nut in general, Big Bore 2 stroke fan.    http://www.youtube.com/watch?v=XJoKP6MawYI
1985 Honda CR500RF "Big Red"
1986 Honda CR250RG
2005 KTM 300EXC "The GruntMeister" ( I love that engine)

Offline mike1948

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Re: Hey guys do you have to split the case to change crank seals?
« Reply #20 on: August 29, 2008, 04:51:57 pm »
Many years ago, while touring in that faraway place called Victoria on my BRAND NEW BSA 441 Victor Special, I came across several pubs/motels which had no vacancy when I rode up to the door.  I found it simpler to park up the road, wrap my helmet in a coat, then wheel the bike in after dark.  Too cold to camp out.  Though I must admit I arrived at one motel in August with my hands frozen to the handgrips, where they somehow got me off the bike, ran a hot bath, brought coffee & soup, and wheeled the bike into the room so it would be more secure.  And no, none of them were bike riders.  One experience like that sure restores the faith.

Offline Hoony

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Re: Hey guys do you have to split the case to change crank seals?
« Reply #21 on: August 29, 2008, 06:32:01 pm »
...... don't want them to find out I'm a motorbike hoon.  

Whats wrong with that?

no worries Mike, i just had a laugh as my surname is actually "Hoon"
Long time Honda Fan, but all bike nut in general, Big Bore 2 stroke fan.    http://www.youtube.com/watch?v=XJoKP6MawYI
1985 Honda CR500RF "Big Red"
1986 Honda CR250RG
2005 KTM 300EXC "The GruntMeister" ( I love that engine)