Generator/Crankshaft nut "Resolved" but

[SEYMOUR]

1983 GS1100E. Looking for the best solution to lock the engine in place while tightening the generator nut? Seen a you tube video where somebody had used a braided rope but don't understand the theory behind what he had done. Manual shows me a spanner wrench on the rotor but until I actually tighten the nut, the rotor is just going to spin freely anyway. What is the consensus on here for the best way to lock the engine down? I'm trying to repair threads at the very end of crankshaft where it had gotten bumped by something. Using a button type M16 x1.5 threading die but because the crank is a hardened steel, it wants to turn before the die cuts damaged area.

 

[Grimly]

Have you tried a decent thread file?

 

[SEYMOUR]

I managed to get my hands on a thread file about an hour ago. Not sure of the quality. Hard to find good quality tools in small town Canada. I think between the thread file, the threading die ,and a small triangular file I should be able to bring it back......slow and steady for the win I guess. I guess the rope is for filling up a cylinder so the piston can't do a full cycle. Friend of mine steered me in the right direction.

 

[Shin-Ken 1074]

You are on the money about using the rope. An "Old School" way to lock the engine is to remove # 1 spark plug, place #1 piston at the bottom of the stroke and on it's way up to TDC. Thread a soft rope into the cylinder through the spark plug hole ensuring enough rope is left outside to prevent the rope disappearing into the cylinder. When the job is done rotate the engine to take the pressure off the rope and slowly remove the rope from the cylinder. I have seen some people mark the end of the rope with a pen marker to ensure all of the rope is accounted for when it is removed.

When I remove or install the generator nut or front sprocket nut a battery powered rattle gun is my best friend. The down side to this method is not having the correct torque setting however, it works for me.

Using a rotor wrench (can be made if you have access to a welder) is the better way to go. When the end of the wrench handle makes contact with the ground the rotor can not spin on the crankshaft and allows a torque wrench to correctly tighten the nut down.

 

[SEYMOUR]

Thanks guys for the suggestions and good info. I was able to salvage things and the nut is winding on and off with ease now. I ended up cutting about 5/32" of the end of the crankshaft though. I had messed up the threads there initially so much that my threading die wouldn't wind on square to the shaft any more so I had to zip-cut that much off and start fresh. After cutting the very end off I took some 220 sanding paper and lightly deburred the end threads. Threading die started nice and square/straight and still plenty of threads to fully seat the nut. Has anybody ever used one of these strap wrenches as a way to hold the rotor when tightening/installing nut or loosening/ removing nut? I remember using mine for uses other than what it was intended for? The more pressure on it, the more pressure, the tighter the strap?

 

[rphillips]

Good, glad you got the thread thing took care of. I had one once that was so bad I never got it acceptable, wound up welding the nut on. I never have installed the rotor on the bench, just waited till on the bike and let the clutch, tranny, chain, and 2x4 in the rear wheel hold the crankshaft.