Stubborn flywheel bolt *help!*

cdsetxo

cdsetxo

New Member
I've just started my first ever motorized bicycle project, but I'm having trouble getting the bolt off that holds the flywheel on. Any tips and tricks to getting it off? I have also broken two fins off the flywheel trying to unscrew the bolt. Should I be concerned about that?
Please help!
 
There's a couple of ways to lock the flywheel. one is to use a strap wrench on the flywheel. the other is use a length of soft rope remove the spark plug and insert the rope in the plug hole, keep a short length still hanging out so you can remove it once the nut is loosened.. the rope will not allow the piston to go past top dead center so now you can remove the flywheel nut. Some flywheel nuts are left hand threads just so you know, I don't now if yours is or not.
Breaking off the fins on the flywheel will throw the flywheel out of balance, just how bad depends on how many are broken off.
 
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Not enough of the flywheel is exposed to properly get a strap wrench around it. That's the first thing I tried. I just got back from the garage attempting to use the rope method, and no luck still. The bolt is on there pretty good, and it doesn't help that it's not that easy to access in the first place. Any other suggestions?
I'm going to call a friend to see if he has an impact wrench, but I'm doubtful
 
Is the flywheel trying to turn? You need to stuff the rope in with the piston not at top dead center. The rope is supposed to lock the piston. Properly done the piston can't go past TDC.
Could also be loctite on the nut some heat will break the loctite. Again I don't know if it's left or right hand threads so try turning it both ways.
 
Yeah, I've got a bunch of rope jammed in, the flywheel has a bit of give to it, but it won't do a complete rotation. I think I just can't get proper leverage on it since it's in such an awkward angle. Will a hairdryer be enough to break the loctite?
 
No you will need a propane torch. I took another look at the photos. You can remove the coil and get a strap wrench on the flywheel. Also look at what it says on the flywheel about it bursting. You have already altered it by breaking off a couple of fins.
 
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What brand and model is the string trimmer?
Have you tried doing a google search on it to find out any info on which direction the nut needs to turn? Also, since the nut also serves double duty as the receiver for for the drive cable, think of what direction the nut would turn if the cable were to suddenly seize as the engine is running. I doubt that the manufacturer would thread it in such a fashion as to cause the nut to unscrew in that situation, rather it would tighten. Knowing that, turn the nut in the opposite direction to unscrew it.
 
Looking at the following video, the shaft maybe tapered and there is a key, so that may be why you are having trouble removing the nut - which isn't a nut but attached to the shaft.

http://www.youtube.com/watch?v=rXqYaYn7InE&feature=results_main&playnext=1&list=PL52FB77CAF2030F88

Here's another video that's kind of lame but explains another shaft removal:

http://www.youtube.com/watch?v=Qlt3hAHbmT4

My guess is that's you are having so much trouble.

Looks like you have a Poulan, Sears, Weedeater flywheel.

Chris
AKA: BigBlue
 
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