bolt stuck in engine

[kevinhancock750]

on the lower front of my africatwin engine the mounting bolt is solid in the aluminium casing any tips for removal?
i cut the 2 steel triangle mounts to remove the engine so have the engine freely at hand....i do have a small gas torch but am worried about breaking the seal on the engine.
any tips greatly recieved......

need to get on with this and stop riding about....

[Mr Beeza]

It's a difficult one, Kev. You don't say how much is sticking out - to grip it with something like a plumber's wrench or a good set of stilsens. You have thought about putting heat in of course, to help the process. Paraffin is a good penetrant if you give it time. This may be well sealed tho' , so not allowing the paraffin inside.

Do you know a good, tame car/bike mechanic for his tips - they get this all the time. Pass on the tip?!

I'd like to hear other ideas too.

[kevinhancock750]

the bolt is still complete, i cut the mountings as i have spares. i been worried about heating it as i'm worried about the center seal?

failing that i suppose i could leave it soak in parrifin...i have time.

[hotbulb]

I think gentle heat would be OK... perhaps a hot air gun: the alloy will expand more than the steel bolt and should (might!) start breaking the bond that's holding the bolt in place. Soaking with parrafin/penetrating oil/diesel, some heat, gentle taps with a soft hammer..... repeated frequently .... should eventually do the trick.

[thetimkirby]

I'd suggest you do both. The corrosion between ali and steel is often a bit porous, and the more time you give the penetrant to soak in, the better. The cases do get pretty hot in use, but if you are concerned about overdoing it, wrap an old towel over the area and soak in boiling water. It will get too hot to touch, but not enough to hurt anything else! Try alternately tapping the end of the bolt and rotating it: any movement at all is good. If it starts moving, flood it with paraffin/wd40/plusgas etc and keep moving it backwards and forwards: this helps wash out the bits of corrosion. If it does start moving, you will almost certainly get it out, with a bit of patience.

If it won't move, you could try alternating more direct heat on the case and cooling the bolt: keep a bit of torque on the bolt if you can. If this doesn't work, you will have to drill it out. Make sure you get the pilot drill dead centre, and drill parallel. Once you are nearly at the full shank diameter, try drifting it out, as the drilling will often allow the bolt to 'shrink' a bit. If you leave the head on and drill from the other end, you might be able to twist it out. If not, you've still got something to hit with the hammer. Good luck, and remember that the bolt is a lot cheaper than the case.