swing arm bolt removal

yellowsnow

Member
hi all
i have got to strip my engine,,but i am having trouble removing the swingarm bolt.
is there an easy way of doing this cos it don't wanna budge(even with a club hammer)
help!!!!!!!!!!!!!!!
 

IndyMX

Crash Test Dummy
You may need something to use to beat it thru with, like a small rod.. something smaller than the diameter of the swingarm bolt.

Once you have the nut off, use a deadblow hammer and beat the piss out of it.. Just make sure you don't wreck the threads.

If it's been a while since it's been out, it may take a considerable amount of effort to get it freed up. But once free, it should come out fairly easily. Although you may need to hammer it all the way out.

Before you take it out, make sure you have a set of swingarm bearings, grease and antisieze compound on hand. If the bolt is that stubborn, there's only one reason, rust.

I'd bet the bearings are shot.

Use the antiseize on the swingarm bolt, and next time it won't be quite as hard to remove.
 

84cr125

Member
if your trying to take the nut off, just use a breaker bar. ONce that nut cracks it will be easy to take off.
 


gncc193

Member
Also while you are knocking it out you should make sure the swingarm is not hanging down freely. If you take the weight off of the swing arm this will help it in freeing it up a little easier.
 

yellowsnow

Member
cheers fellas
i have another question for ya,,
i just received my new piston,but it doesn't fit in the barrel,does this mean i have to have the cylinder rebored to fit the new piston??
thanks for your imput it's been 17 years since i owned a motocross bike
 

_JOE_

Subscriber
IndyYZ85 said:
You may need something to use to beat it thru with, like a small rod.. something smaller than the diameter of the swingarm bolt.

Once you have the nut off, use a deadblow hammer and beat the piss out of it.. Just make sure you don't wreck the threads.

If it's been a while since it's been out, it may take a considerable amount of effort to get it freed up. But once free, it should come out fairly easily. Although you may need to hammer it all the way out.

Before you take it out, make sure you have a set of swingarm bearings, grease and antisieze compound on hand. If the bolt is that stubborn, there's only one reason, rust.

I'd bet the bearings are shot.

Use the antiseize on the swingarm bolt, and next time it won't be quite as hard to remove.
Great advice. I've heard of people actually having to use a sawzall and cut it on either side of the engine :yikes: . Hopefully all goes well for ya!
 


IndyMX

Crash Test Dummy
_JOE_ said:
Great advice. I've heard of people actually having to use a sawzall and cut it on either side of the engine :yikes: . Hopefully all goes well for ya!


Ouch.. that'd suck.

I took the linkage off my CR a couple months ago. The bolt on the link that attaches to the frame right under the swingarm pivot was so tight I had to beat it with my 2 1/2 pound sledge.. It came out, but I had to beat it all the way thru. Now that it's been out and cleaned and lubed, I can take it out by hand.
 

_JOE_

Subscriber
Yeah, if we could just get people to do maintenance! That way when we buy a used bike we dont have to go through all that crap.
 

Ol'89r

Member
If you tried everything Joe suggested and it still won't budge, take two 4"X4" blocks of wood and lay them on the ground. Then lay the bike on it's side so frame is laying on the blocks of wood and the swingarm bolt is in the middle of the blocks.

This gives you something to beat against without allowing the frame to flex. A little heat where the swingarm bolt goes through the engine will also help. :cool:
 


yellowsnow

Member
cheers everyone
think i'll try laying it down next weekend and beating the granny out of it.
still unsure about the new piston being biggerthan the cylinder,,is this right?
if so that means i gotta get the cylinder bored to fit the new piston?? thanx again
simon
 

Ol'89r

Member
yellowsnow said:
still unsure about the new piston being biggerthan the cylinder,,is this right?
if so that means i gotta get the cylinder bored to fit the new piston?? thanx again
simon

If your 125 is a late model with a plated liner, then you have the wrong piston. Plated cylinders should not be bored. Take your cylinder to your local shop or machine shop and have them measure the bore for wear and taper. If the bore is ok, get the right piston and install it. If the bore is worn excessivly, you can have it re-plated back to the original size.

Check on Eric Gorrs website for this service.
 


yellowsnow

Member
the bike's quite old it's a 1991,,the cylinder bore is 55mm and the new piston is 55.95mm.
i spoke to a rebore shop and they can send it off and do it for about £45.
the shop i got the piston from said the standard bore is 56mm.
the sylinder doesn't look like it's sleeved either,,so i think i'll have to go for rebore.
a friend gave me the bike for nothing and as i haven't owned one in 17 years i couldn't say no could i??