Removing a stuck bolt.

[Pinchers]

Ive been working on a old CR250 (1994) ive been trying to remove the engine but been havin some problems, im trying to remove the pin that holds the back of the engine in and also holds the rear swing arm on, im having alot of probs getting the pin out so that i can seperate everything, can anyone give me and advice?

[DaveS]

Well this is quite a generic problem.
I have what sounds like the exact same problem with my XR400, so perhaps have a look at my thread in the XR forum on that. Haven't got time to find it at the moment.

Heat is also worth thinking about.
I'd also consider posting in the bike tech forum as some people won't look in here and shifting a stuck bolt is something we've all faced!
In fact I'll duplicate the thread for you, but I'm going to change the title to "Removing a stuck bolt".

[Snaphappy]

as in Nuts Off but bolt wont move.
its probably under too much tension especially an engine mounting bolt try jacking or levering the part up to free off tension, if you can replace the nut at least a few turns to protect the thread and tap it with a hammer, if its really stubborn get someone else to lever whilst you tap the nut ifs its really really stubborn get a bigger hammer and tap it with more vigour

[AlanH]

These corrode into the back of the engine. They really need taking out and greasing every six months to guarantee they won't weld themselves in.

Lots of penetrating oil and heat are required. Feed it penetrating oil over the course of a few days and then give it a go. You'll need an old nut to thread onto the spindle and an old socket to go over it and hit that. Remove the back wheel and shock and go in through the back to get heat on the right bit. Heat up the back of the engine casing where the spindle goes through. Don't hit directly on the spindle otherwise the end will mushroom and it will never come out. Keep bashing the old socket and then pausing for a go at trying to turn the spindle with a long knuckle bar. If nothing happens, try heating again and repeating. Hopefully it will come loose. If not, you're in for some trouble.

I've heard of all sorts of drastic stuff such as laying the bike on its side and using a sledgehammer or cutting the swingarm. If all else has failed, there was a suggestion I read on crm250.com to drill into the rear of the crankcases at the join as vertically as possible down to the seized spindle with increasing drill sizes and then fill the hole with penetrating oil so it soaks in from the middle too.

Ultimately it's one of those jobs that inspires you never to neglect suspension and spindle greasing ever again.

[gwernybwch]

All good advice.

One method that I tried was to heat it up (and I mean orange hot all over) and then leave it go stone cold. After then a fully seized bolt tapped out quite easily.

I'm told that the reason why this works is that the swingarm and the bolt itself are made out of different metals they expand and retract at different rates. So effectively the two metals seperate from each other.

I hope this helps.

[TRANSPORTER]

PLUSGAS PLUSGAS PLUSGAS PLUSGAS PLUSGAS!!!!!!!!!!!!!!!!!!!!!!

This stuff is ace its like WD40 on steroids. I had a seized swing arm bolt, tried heat tried large hammers tried wd40 even layed the bike on a bench and got a 5 ton strong back to push the bolt through,even hired a reciprocating saw to try and cut the bolt out, ended up in a bike shop for a week and still it was stuck.
In the end I got a can of PLUGAS laid the bike on its side and for three days I sprayed PLUSGAS morning and night onto the swing arm bolt and areas and on the fourth day i got my drift and mallet went for the big hit as you do but first done the sighting tap (finger protection dont you know) on this tap the bloody bolt moved second hit and it was out.
Bike was off the road for about a month getting this done when really I could of taken a long weekend and done it myself.