Primary side engine sprocket removal

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:( Did a search without any luck. I tried to remove the sprocket today with the correct tool and was unable to get the sprocket to budge one bit. The longer bolts of the puller have now been bent out of shape, and the tip of the pusher bolt is a mess. I tried heat, PB blaster, and a BFH. Im to the point where Im going to cut the chain, and use a larger puller. Im concerned because I was starting to mangle the drive shaft alittle, and had to reshape some of the first part of the threads with a file. Anyone have any other suggestions?
 
Man, that sounds like it's been welded on there. I've always gotten by with a sfh of a mfh just tapping the sprocket as pressure is applied with the puller. Before I had a puller I used the foot peg mount with the correct bolts through to the sprocket. 2 of the 3 holes on the flange where it mounts to the z plate lined up to the sprocket holes.

You can get master links for the triplex chain (don't know how easy they are to find) so you could take the chain apart if you got desperate.
 
Don't beat up the shaft. That would be a problem. Give it time. It is a slight taper fit on the shaft. Use plenty of penetrating oil and give it a few days if necessary. Keep the pressure on it and since it is a taper fit, it wouldn't hurt to use some side pressures on it, but not to beat up anything. See if you can push the key around with a small punch, that may help but don't spread it. Be patient with it, it will come off, unless like RennieK says it is welded on.

Dave
69 S
JD 2020
2000 Miata
 
Ill see what I can do. i think im going to grind the 1/2 bolt to a point to actually fit it in the hole of the shaft. The main problem was the bolt walking around on the end of the shaft. I might also pick up some new 5/16" bolts to make sure things stay straight. There looked to be alittle rust in the area, since the bike sat since the early 80s.
 
Vulin said:
:( Did a search without any luck. I tried to remove the sprocket today with the correct tool and was unable to get the sprocket to budge one bit. The longer bolts of the puller have now been bent out of shape, and the tip of the pusher bolt is a mess. I tried heat, PB blaster, and a BFH. Im to the point where Im going to cut the chain, and use a larger puller. Im concerned because I was starting to mangle the drive shaft alittle, and had to reshape some of the first part of the threads with a file. Anyone have any other suggestions?

Hopefully you've removed the woodruff key for the alternator rotor.
 
yes all necessary items are removed. Im going to hit it with some PB blaster when i get the chance, and slowly work at it. I was hoping to have the primary casing off, and reinstalled in a few hours.
 
With the few odd jobs I've done recently on Nortons I get the impression many of the fixing nuts and bolts have really bedded in over time. They seem harder to get off than they used to be, possibly due to the time involved that they've been sitting.
 
They can be on there good. Had mine off to replace the drive chain not more than a year ago, and when I went back recently in order to remove the gearbox, the sucker was still very hard to get off. Best advice, crank up the pressure on the puller bolt, PB Blaster or Kroil liberally, and tap (with a hammer - okay, tap shit, whack that suckah!) a brass drift against the sprocket. Crank up a little more. Let sit. Repeat. When it goes, it goes all at once and you wonder what the heck the problem was. Best of luck.
 
If I was older and more patient, I would like to strip the whole bike down. But at the moment I want to fix a couple things, finish my new harness, and ride the piss out of the bike. I should have expected there to be problems, especially with a bike that sat for 25+ years
 
If you're willing to give it a bit of time to soak I remember reading this a while back.
Seems like the best stuff to use is a home brew of 50/50 ATF and Acetone!

*Don't forget the April 2007 "Machinist's Workshop" magazine comparison
test.*
**
*They arranged a subjective test of all the popular penetrants with
the control being the torque required to remove the nut from a
"scientifically rusted" environment.*
**

*Penetrating oil ..... Average load*

None ..................... 516 pounds
WD-40 .................. 238 pounds
PB Blaster ............. 214 pounds
Liquid Wrench ..... 127 pounds
Kano Kroil ............ 106 pounds
ATF-Acetone mix....53 pounds

*The ATF-Acetone mix was a "home brew" mix of 50% acetone - 50% automatic transmission fluid.*
*Note the "home brew" was better than any commercial product in this one
particular test. Our local machinist group mixed up a batch and we all now
use it with equally good results. Note also that "Liquid Wrench" is about
as good as "Kroil" for about 20% of the price. *
 
Penetrating oil is a waste of time, the sprocket is locked on the taper,if you are screwing the bolt for the puller directly on to the end of the crank without a hardened spacer you wont be getting full pressure on the puller, it sounds like you puller is twisting, not pulling straight so you wont be getting full pressure any way. Plenty of moly grease on the puller threads and on the end of the puller bolt helps get more pressure, when you get it pulling straight with plenty of pressure on the bolt it will require a sharp shock on the end of the puller, or heat on the sprocket to rapidly expand it, yes I read the other comments, no heat no hit spray with penatrating oil and it will fall off all I can say to that is WHAT A LOAD OF TOTAL CRAP :!: Protect the end of your crank and get your puller pulling square on a hard spacer is more important to start with.
 
The last post is interesting - hadn't seen that before. I've heard diesel works too.
I've had some total nightmares like this before - the latest being the 'hand tight' oil seal holders in the forks.
In every instance, with no exceptions, the application of heat has done the trick.
I've found that the puller doesn't need to wound up to the point of distress - just applying a decent load.
I've never had to apply the blowtorch for more than a minute or two before the sprocket/Ducati flywheel/Ford cam pulley (sorry!) has just fallen off...or flown across the workshop.
As long as the heat is applied 'correctly' it doesn't do any damage whatsoever.
In the past I have has to resort to a welding torch used carefully, but not in recent history.
 
You have to hit it pretty good with a rosebud tip or cutting tip (do not use the oxy blast)

Quickly get it VERY hot, while under as much pressure from the puller as possible, then SMACK it (the end of the puller) good, with a heavy hammer.
 
Ill give everything a try. I wont be able to get back to it till later in the week. There is no reason it should be welded on, I was removing the primary case to replace the engine/case gasket. I believe the topic of the puller twisting is correct. I was having a hell of a time trying to keep the puller straight.
 
One thought would be, if you sick and tired of the hassle of trying to pull it, just leave it the way it is.

I forgot to put the same gasket on ten years ago and have just left it that way. No big deal at all if you just leave it there.
Now, if you are trying to pull it to get to replacing the crankshaft seal as I did last week, that is good reason to get the sprocket off!
 
The 2 threaded holes in the sprocket are 5/16 fine thread. If you have a slide hammer that will screw in you can try that as well.
 
rx7171 said:
If you're willing to give it a bit of time to soak I remember reading this a while back.
Seems like the best stuff to use is a home brew of 50/50 ATF and Acetone!

*Penetrating oil ..... Average load*

None ..................... 516 pounds
WD-40 .................. 238 pounds
PB Blaster ............. 214 pounds
Liquid Wrench ..... 127 pounds
Kano Kroil ............ 106 pounds
ATF-Acetone mix....53 pounds

I wonder how well Mouse Milk would have compared. Probably wasn't around at the time. It's a favorite in the areospace world.
 
One thing I have done on tough ones is use a MAP torch for faster heat then quench with cold water . DO that several times with the puller in place then the last time heat and hammer with no quench. Probably will lose the seal but it's a good time to put one in anyway.
 
Got it...I ground the large puller bolt down to slide into the shaft so it wouldnt walk. I was able to get the puller to pull straight, soaked it in PB blaster, and used a propane torch to heat the sprocket. Took me about 30min of slow pulling, and heat but it came off with quite a POP. Thanks to all for their advice
 
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