Anyone tried heating bolts

[sbhumphrey]

Alas I need to remove a now headless bolt that is part of the starter motor and I have been recommended to remove the side casing, all the other bolts and then heat and gently tap the starter motor. Anyone had experience of this, must admit I'm nervous about applying heat directly?

[utopia]

It would appear that the bolt in question passes through a plain/unthreaded hole in the case, then screws into the starter motor casing only. It shouldn't be that hard to shift, in situ. I'd give it a stiff wire brushing, then a few sharp taps with a hammer and punch (this will crack any corrosion) then soak for hours in wd40.
I would expect it to move fairly easily after that, with a bit of encouragement from the punch again....a little localised heat on the casing may help but probably won't be necessary. You wouldn't need much heat anyway...the aim is to heat/expand the alloy casing while leaving the bolt cold.
Obviously, heat should be kept well away from the starter motor itself
Make sure that ALL of the bolt head has been removed though, as you'll be pulling the bolt through the case in the wrong direction.

According to my manual, there are three such bolts holding the starter motor on, access to the other two is gained after removal of the outer engine case.
One of these internal bolts is hidden behind the starter idler gear, which has to be rotated until the bolt is visible through a hole in the gear.
It would be best to loosen these two internal bolts a little, before punching the broken one.

[rollo22]

There is a special socket that is designed to grip on such things it has teeth that grip and wind it on whilst your undoing the offending nut/bolt.
One make is Irwin tools,Snapon and i imagine the rest will make one

Chris Yeatman should be able to give it its correct name

[PaulR]

It's a longer process, but if you remove the alternator casing you can take out the other two bolts which hold the starter (even Ducati haven't found a bolt which corrodes on the inside of the engine - although I'm sure there's a team working on it) With the starter motor off you have a better chance of getting the rest of the bolt out - it's not too hard to take the end of the casing off the starter, and then you can get some heat on it with a heat gun. Good luck!

[utopia]

Just to clarify....my previous post was concerned with removing the bolt (and starter motor) from the engine casing.
Obviously, you would still have to remove the broken bolt from the starter motor itself.
My approach to this would be the same, ie stiff wire brushing, sharp blows on end of bolt, soak in wd40 for hours etc.
Then I'd use a stilson (pipe) wrench to turn the bolt. Turn it a little bit in both directions, and keep hitting the end of the bolt from time to time to jar the threads, and reapplying the wd40.
I'd try it gently without heat first, being carefull not to overstress anything (ie don't snap the bolt), before resorting to the heat.
And I'd be very careful with the heat, for fear of damaging the insulation in the starter motor.

Sorry if some of that is obvious.

[dunlop0_1]

Without a second thought I would drill the head out. It's an M6- 8.8 capscrew very easy to do. Then remove the starter and work on getting the remainder of the bolt out while on a workbench. Although the already mentioned methods would probably work I would be reluctant to hit any of that area with a punch and hammer due to it being right on the edge of the crankcase especially if the other two bolts have been removed. Old aluminium and hammers don't really mix well.

2mm drill followed by a 6.5mm drill

[Dukedesmo]

Drill the head off and then remove the other bolts from inside the case so that the motor comes away with the bolt sticking out that you can grip in the vice.

And give the whole thing a good clean... ;)

[Capo]

And give the whole thing a good clean... ;)
:biggrin:..............

[utopia]

Good point about the dangers of hammers.
I guess I would have instinctively supported the rear of the case with something heavy if it seemed vulnerable, but I'm not talking about big blows...just a sharp tap to jar things a little.

Not sure it'll need drilling though, to get it out of the engine case, and if you do drill you've then got much less remaining to grip when trying to get the last bit out of the starter...or else just a hollow bit rather than solid, which might easily shear, leaving you having to drill the threaded bit out too, which isn't so easy.
But if it doesn't come out of the case easily, then yes, I'd drill it out too.

And it does look a little grubby......I wasn't going to mention

[gary tompkins]

Drill the head off and then remove the other bolts from inside the case so that the motor comes away with the bolt sticking out that you can grip in the vice.

And give the whole thing a good clean... ;)

Or carefully take head off with a dremel for same result

I had to do this with a couple of fooked exhaust studs

[Gadget]

I sheared the same nut on my 600.
You can get to what's left of the bolt once the starter motor is removed.
Take the engine casing off to get at the bolts that are still holding the starter motor in place. Tap lightly with a hammer to loosen the motor from the engine.
Use mole grips or similar to remove the sheared stud.
Mine snapped inside the motor so I put it back with just the 2 nuts as a temporary thing. The bike did 40,000 miles without any problems afterwards.

[johnboy44]

Just had the same prob on my 94 m600, I filed the leftover bit flat, a good central pin punch and drill 3mm drill followed by a 5mm about 8mm deep. with the other two bolts removed the motor just dropped out with some gentle tapping, good luck

[a7avenger]

To add to the catalog of woes that I've had with my Duke the same bolt sheared off flush
with the locating face of the starter motor. I guess it took about 4 pounds/foot to do this as
the bolt was so rotten.
I'm in the process of making a drill jig to redrill the offending hole accurately.

[digga]

all good points , but don't bother with WD40 its for moving water. you need a good easing oil that will seep through the corrosion.
having said that, drill it out / off .