Backing out cylinder studs

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7/27/2017 10:11 AM

For the life of me I can't seem to back out the studs on my 04 yz250 cylinder. I recently shattered the piston skirt and I'm rebuilding top to bottom. I have a brand new cylinder that just needs the studs from the old. I've tried liquid wrench, heat, and three nuts on one stud and they just won't budge. Any tips or tricks from you guys? I could really use them as I'm cursing and sweating my ass off in the garage.

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Ex Pro BMX rider. Lover of all 2 wheeled machines.

1978 XR75
1994 KX250
1997 KX250
2008 CRF450
2004 YZ250

7/27/2017 10:20 AM
Edited Date/Time: 7/27/2017 10:21 AM

Liquid wrench is garbage. Get yourself some Aerokroil - https://www.amazon.com/Kano-Aerokroil-Penetrating-aerosol-AEROKROIL/dp/B000F09CEA

Let it penetrate for up to 12-24 hours. Apply more heat before trying to back them out. A lot of heat.

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7/27/2017 10:23 AM

Try heating your engine from below, also. The trick is to warm the engine cases more than the studs. If you blast the studs with a blowtorch, you are just expanding the studs in their holes.

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Braaapin' aint easy.

7/27/2017 10:24 AM

Swann wrote:

Liquid wrench is garbage. Get yourself some Aerokroil - https://www.amazon.com/Kano-Aerokroil-Penetrating-aerosol-AEROKROIL/dp/B000F09CEA

Let it penetrate for up to 12-24 hours. Apply more heat before trying to back them out. A lot of heat.

Thanks Swann. I'll look into Aerokroil. I've got no worries warping this cylinder so I'll go for more heat too.

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Ex Pro BMX rider. Lover of all 2 wheeled machines.

1978 XR75
1994 KX250
1997 KX250
2008 CRF450
2004 YZ250

7/27/2017 10:43 AM

It sounds like new studs will be the safest bet. After applying heat and torquing them out of the old head, can they really be trusted?

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7/27/2017 11:07 AM

Radical wrote:

It sounds like new studs will be the safest bet. After applying heat and torquing them out of the old head, can they really be trusted?

I would have to recommend new studs as well, I wouldn't be worried about the integrity of the metal, since they will feel much more stress during tightening then they would being removed, however I would be concerned about the integrity of the threads since doing the double nut method is likely to cause them to yield. Once the threads have yielded, forget it, they're junk.

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7/27/2017 12:20 PM

If I can't get them out without messing up the threads I'm definitely going to buy new studs. They aren't that exspensive but I just figured I could save a few bucks and get the old ones out. Thanks for the tips though.

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Ex Pro BMX rider. Lover of all 2 wheeled machines.

1978 XR75
1994 KX250
1997 KX250
2008 CRF450
2004 YZ250

7/27/2017 12:36 PM
Edited Date/Time: 7/27/2017 12:40 PM

KBOLTZ wrote:

Thanks Swann. I'll look into Aerokroil. I've got no worries warping this cylinder so I'll go for more heat too.

@Falcon up there has some good advice as well - where you concentrate the heat is important. You want the cases surrounding the studs to expand. A good pinpoint butane/propane torch usually does the trick.

When it comes to engine work, I generally avoid anything involving a hammer or a "whacking" motion but a common trick to loosen rusted bolts is to whack the head with a hard rubber mallet or ballpeen hammer to 'shock' the threads/corrosion loose. Walk a fine line here since this is a cylinder head. Do it after heat. When trying to back out the stud, gently apply torque in both directions (loosen, tighten), ever so slightly with gently increasing positive torque. You're trying to 'jostle' things loose.

In the end, you may just be better off getting new studs.

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7/27/2017 3:49 PM

go new---be truewink

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If I'm healthy enough to complain. I shouldn't be complaining.

7/27/2017 4:25 PM

There is a tool for removing studs, it grabs them below the threads, it's very handy tool to have. EBay or Google it

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Old Vintage Gold Rules

7/27/2017 4:31 PM

There is a tool for removing studs, it grabs them below the threads, it's very handy tool to have. If not this time Next time. EBay or Google itPhoto

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Old Vintage Gold Rules

7/27/2017 4:32 PM
Edited Date/Time: 7/27/2017 5:07 PM

Don't even bother. Just get new studs. Your time and frustration is worth much more than a few new studs. Not to mention they'll probably be ruined by the time you get them out. laughing

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7/27/2017 4:57 PM

There is a really good chance you are gonna take the threads out with the stud.

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7/27/2017 5:15 PM

Ive got a set of cornwell stud removers. They look like sockets. They wrap around the stud and tighten down when you turn them. Have pulled studs out of a 5.0 motor, many dirtbike motors and have never had them slip either. Look around for those. Thats the correct way to do it.

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2009 Kawasaki KX450F
2009 Kawasaki KX250F
2002 Suzuki GSXR 600

7/27/2017 5:28 PM

I use cutting wax instead of penetrating oil in combination with heat, but I agree, if you've torched the shit out of them already it is better to just buy new studs.

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Nick
-2015 Grom grocery getter
-2011 Road King Classic
-2010 WR250X supermoto

7/28/2017 8:52 PM

Always use new studs. Metal may have fatigued and not give correct compression when head nut is torqued . I remember a guy having chronic head gasket leaks until he changed the head studs in his KX250. Cheap insurance.

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7/28/2017 9:04 PM

New studs it is. Thank for all the info guys. Should be back on the track soon enough.

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Ex Pro BMX rider. Lover of all 2 wheeled machines.

1978 XR75
1994 KX250
1997 KX250
2008 CRF450
2004 YZ250

7/28/2017 10:17 PM

yzweldon wrote:

There is a tool for removing studs, it grabs them below the threads, it's very handy tool to have. If not this time Next time. EBay or Google itPhoto

That's what I was going to recommend too. As you turn it, it tightens on the stud and gets it right out. Just count on replacing it because it will ruin the threads.

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