yea! i did it!
Jun 24, 2008 | 08:39 AM
#2
Pro Rider
Joined: Jul 2007
Posts: 338
Likes: 0
yea! i did it!
JMR - Here is a 'trick' for removing ANY broken bolt that you can get to the rear side of ( it works 'slicker than Goose Sheat' ).
1st - Get a scrap piece of 2" x 6" or 2" x 8" and drill a 3/8" to 1/2" hole thru it. This hole acts as a 'receiver pocket' for the broken bolt to spin into.
2nd - Turn the gear upside down (reverse side of gear) with the broken bolt positioned over the 'receiver hole' in the 2" x 6".
3rd - Take a VERY sharp center punch and center punch the end of the broken bolt. This should be easy to do since you are working on what was the original square factory end of the bolt.
4th - Get a drill bit that is SMALLER than the INSIDE diameter of the threads in the gear. Start to drill out the bolt, using a battery powered drill - so that you can control the speed. Drill VERY slowly. Make sure that the drill is spinning in the 'regular' forward direction - NOT REVERSE.
5th - At some point, very early on in the drilling process - the drill bit will 'bite' into the bolt end and start turning the bolt. The broken bolt will spin right out into the 'receiver hole' in the 2" x 6".
6th - The whole reason that this works is because you are drilling from the 'backside' of the gear. Drilling in the clockwise 'forward' direction on the reverse side of the gear is the same motion on the bolt as though you were working on the front side of the gear using a reverse or counter-clockwise loosening motion.
7th - I hope that this helps you - what happened any way and why did the bolts in the sprocket shear ???
1st - Get a scrap piece of 2" x 6" or 2" x 8" and drill a 3/8" to 1/2" hole thru it. This hole acts as a 'receiver pocket' for the broken bolt to spin into.
2nd - Turn the gear upside down (reverse side of gear) with the broken bolt positioned over the 'receiver hole' in the 2" x 6".
3rd - Take a VERY sharp center punch and center punch the end of the broken bolt. This should be easy to do since you are working on what was the original square factory end of the bolt.
4th - Get a drill bit that is SMALLER than the INSIDE diameter of the threads in the gear. Start to drill out the bolt, using a battery powered drill - so that you can control the speed. Drill VERY slowly. Make sure that the drill is spinning in the 'regular' forward direction - NOT REVERSE.
5th - At some point, very early on in the drilling process - the drill bit will 'bite' into the bolt end and start turning the bolt. The broken bolt will spin right out into the 'receiver hole' in the 2" x 6".
6th - The whole reason that this works is because you are drilling from the 'backside' of the gear. Drilling in the clockwise 'forward' direction on the reverse side of the gear is the same motion on the bolt as though you were working on the front side of the gear using a reverse or counter-clockwise loosening motion.
7th - I hope that this helps you - what happened any way and why did the bolts in the sprocket shear ???
Jun 24, 2008 | 09:54 PM
#4
Pro Rider
Joined: Jan 2007
Posts: 983
Likes: 0
yea! i did it!
The Jetmoto 250's have known to have the rear sprocket bolts come loose then if not fixed will shear off and has even sent the head of the bolts into the bearing next to them and has done damage. All 250's should have these round headed sprocket bolts replaced as I have done and can be seen on my Mods and Repairs page on my site Repair. Grab your rear sprocket and if it is loose at all a fix needs to be done. Some here has put longer bolts in it and placed a nut on the other side, I simply replaced mine with hardened bolts and Loctited them in place.
