Honda CG 125 - Stuck bolt!

[ryosaurus]

Hi all,

I'm restoring a 2001 Honda CG125 and have a bolt holding the engine which will not budge. I've attached some photos, it's bolt #17.

From the manual, it doesn't look like it's threaded but I have sprayed it with WD40, taken a club hammer to it and it still will not move. If I wiggle the engine there is play in the bolt.

Does anyone have any ideas for removal?

Cheers!

[mudcow007]

thats an engine bolt/ mount isnt it?

have you mushroomed the threaded end of it hitting it with a hammer?

if i remember my old CG that was the bolt that was bastard to refit, basically my engine had moved an pinned the bolt in - if that makes sense

[ryosaurus]

[bikenut]

keep spraying penetrating oil into the holes.......and into the gap tween frame and engine.......allow to penetrate for some time........good fitting socket on the bolt head and gentle turning ....the trick is to get the bolt to turn first.....may be some gentle hitting with a smaller hammer so that the shock goes thru the bolt rather than the shock riveting the ends over.........a brass drift or similar of dia about at least 1/2 inch would protect the bolt.........

I would suggest lying across the top of the bike, side to side, and hitting the hammer system from above....a good swing and a steady bike........so force goes into bolt rather than rocking the bike and riveting the bolt.........

when that has failed, try heat as well.

sometimes water is a better lub as it is free ( it falls out of the sky! ), biodegradeable, causes rust etc on metals and washes out any rust/corrosiion free'd by your actions.......
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[Rogerborg]

It won't rotate? No movement at all?

Have you tried jacking the engine up to take the weight off of it?

WD-40 is not a release agent. I'd switch to PlusGas or another actual penetrating fluid.
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[ryosaurus]

[mudcow007]

i had to wiggle the engine around to get mine out, it had a blob of rust on the shank (non threaded bit) - if that makes sense

it was a swine to get out though

the engine seems to hang on that bolt

[bikenut]

water to wash out corrosion etc......shock to free of stuck ( corroded in ) bolt etc......water to wash out corrosion......heat to expand the alloy and other materials somewhat...water to quench ( thermal shock ) and water to wash out corrosion.......get the bolt to turn.........gentle tapping ( a good direct hit rather than tickling the thing ( not bashing as that will rivet the bolt in and damage stuff ) )_ so bolt moves and turns....water to wash out corrosion...........and lots of patience....drill the bugger out as a final and last resort.......so get it to move out a fraction then tap back in, get it to turn and patience......dont forget the occasional please god..... :D
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[zark]

is the weight of the engine keeping it tight? Can you support the engine with a jack or something?

also - has #17 not got a #11 and #14 on the other end?

[c_dug]

You need a bigger hammer.

Actually, pressing it through would probably be your best bet but I'm not sure how you'd do that with tools you're likely to have around the house.

One thing though, if it was me I'd do something to protect the end of the thread, any more flaring and you'll struggle to get it through the hole. Ideally you would have had a nut on it from the start, not sure what you can do now because there's bugger all hope of getting a nut on the end of there as it is.

Maybe work it back with a file and get a nut on the end before bashing it any more.
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[WD Forte]

You could ( carefully !) counter bore the bolt head and the protruding threaded end of the bolt off to get the engine out.
Then you'd have the engine out, but obviously still have
the remnant stuck inside the engine case to deal with
so some more (careful) counterboring, heat, ACF 50 etc may help here.

I've done similar to get 30 year old mainstands off whilst muttering
"would it have killed some bastard to grease the bloody thing?"
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[N cee thirty]

if its seized inside the engine mount and you twat it too hard, i do hope it won't crack the mount on the engine, not sure how you'd get it out, can you get a hacksaw on the inside of the mount next to the engine to chop the end of the bolt out on either side?
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[Teflon-Mike]

flat the end of that thread;
Then use electric drill to put a counter-sink in the end.
The the niftybit; a knackeed SDS masonary bit, dipped in grease, run t in the coutenr-sink, let hammer action on drill do the hammering, little & often.
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[killerbanjo]

Whatever you do try not to snap the head off! I did that on my engine and ended up having to do a FULL rebuild as well has having to buy some second hand crankcases off of ebay!

[Sload]

[Teflon-Mike]

SDS drill bit trick can be remarkably effective.... even an old fashioned percussion-hammer drill can do the job surprisingly well... was a bit of improvisation I employed many years ago when I no longer had access to shared work-shop with the wonders of a pneumatic chisel!

You can a get (and I now have) SDS chisel bits, and if you can get one to fit in countersink in end of the bolt, work just as well as blunted old masonry bit.

Trouble usually is that the steel bolt has 4" of shank in the alloy of the crank case, and only 1/4" either end through the steel lugs on the frame. A-N-D its in one of the most least seen crud traps on the bike, with little reason for it ever to be touched. & You get higher rate of corrosion between dissimilar metals on the long bit of bolt, effectively welding bolt in place.

HINT: - Brute force tends to see the weakest link give first.. A-N-D.. that tends to be the human on the end of the hammer, shortly followed by the frame lugs.

Craftiness & patience often works better than gross force, power-tools and fire!

When it comes to cutting, the humble hand-powered hack-saw is your best friend.. may take elbow grease, but once you have a slot for it to follow, it is often the most accurate and least destructive way to cut....

If you have undone the nut then the clamping pressure on the the nut end engine plate is relieved, but often not relieved the head end if bolt cant move in cases.

Big metal of the hex-head can be taken off with an angry-grinder, but last 1/4" or so should be taken flat to the plate with a file. That can give enough 'play' to be able to use a pry-bar to waggle the engine plate away from the crank-case, enough to get a hack-saw blade in between casing and plate to cut through bolt.

Do both sides; motor should drop out.. HINT:Straps/rope/Old coat-hanger wire, or similar should be used to hang the motor from the frame's back-bone until you are ready to 'catch'... but bits of bolt going through frame lopped off, should come out, without too much risk of buggering the frame plates.

How to get the shank of bolt out of the crank-cases?

Well, with the engine out the frame; you do have more options and more access.

a) You can return to the SDS drill trick and or big hammers, with the motor laid on its side so yo are bashing the thing into the floor, rather than knocking the whole bike side-ways... change of orientation alone may be all you need to direct force where required.

b) Engine reconditioning type places often have big presses, and for price of a pint, might pop the motor on its side under 20 tons to make bolt budge...

c) Back to the hack-saw; carefully slot the 'boss' the bolt passes through in the crank-cases, along the line of the bolt, until you touch steel. Boss now has a C-shape cross section instead of an O-section, and can be expanded (a little) more easily; while you can also get penetrating oil more directly where its needed. Bit of oil, bit of bashing and the thing will usually give up its grip on the shank.

Structurally; as long as you haven't taken a huge chunk out, a small slot wont effect the strength of mounting when re-fitted; it's mainly taking load along the length of the bolt that is usually a pretty slack fit that hole any way, the torque reaction shared by four or so other mounting points; but if it irks or a cosmetic repair wanted, the crack can be filled with lumi-weld or similar.
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My Webby'Tef's-tQ, loads of stuff about my bikes, my Land-Rovers, and the stuff I do with them!
Current Bikes:'Honda VF1000F' ;'CB750F2N' ;'CB125TD ( 6 3 of em!)'; 'Montesa Cota 248'. Learner FAQ's:= 'U want to Ride a Motorbike! Where Do U start?'

[ryosaurus]

[DMCpro]

Put a good impact wrench on the bolt spin it and get a mate to hit it from the other side. It sounds like you've got weight on the bolt though ??
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