Having Trouble Removing Drive Sprocket with 80cc 2 stroke

GoldenMotor.com

SomeGuy

New Member
Nov 22, 2015
20
1
1
Michigan
Hello All

Currently I have been taking apart my 2 stroke 80cc Engine. I got all the nuts and bolts out but I have come down to the Drive Sprocket, which is not allowing me to open the crank casing. I stripped the clutch puller on the drive sprocket many times with multiple methods and it would not budge! Are there any alternative ways to removing the drive sprocket and is it possible to keep the drive sprocket on and open the crank case?

Some insight would be greatly appreciated!

SomeGuy
 
Aug 26, 2015
472
6
18
Overgaard AZ
Two options come to mind, for when all else fails, both handed down from the Santa Fe Rail Road.

Option 1. BFH, Big Foulword Hammer, never force it, simply implement a larger "Arguing Instrument". (Joke)

Option 2. Smoke Wrench, when the BFH fails, light the torch. Concentrate your heat on the female threads, the metal will expand, possibly allowing a puller tool to work. (Not a joke)

Or, if you don't own a torch (~$20 at any Ace) PB Spray, or Kroil, or any good penetrating oil (I recommend Z Preserve or PB) and wait for a while. Tap gently with a hammer as you work your wrenches/tool.

These methods are used every day for various fasteners. I've never pulled my motor apart, so I can't give advice on the particular issue you're having. Also be cautious using any method, it's easy to screw things up from shear frustration, and any method mentioned above can cause serious damage when carried out carelessly.
 

SomeGuy

New Member
Nov 22, 2015
20
1
1
Michigan
@mogollonmonster

Yes, I should have detailed what I attempted. At first I kept on grinding down the stripped threads on the clutch puller, I had tried hammering throughout. After those attempts, I took it to my bro's and we tried torching it and hammering it and more grinding. After many tries, I attempted to super glue the threads. After that fail, my bro welded the tool to the drive sprocket (multiple booger welds) and after a great effort, the welds split and the sprocket didn't move even a bit. The tool is toast at this point, as the effort involved even made the puller bolt go crooked.

Clutch Puller Tool

https://gyazo.com/c9dabe4127f919a8f3d0baef1faab2b4

Drive Sprocket

https://gyazo.com/20777379ef63f389219e0c0d45be6840

The reason I wanted to open up the crank case on this thing was because it leaked fuel along the gasket and into the clutch gears and magneto through those seals, and now I am sure the seal behind the drive sprocket was destroyed by the torch as it bubbled up. I am considering getting a new engine.

Any advice?

SomeGuy
 

crassius

Well-Known Member
Sep 30, 2012
4,032
158
63
USA
the puller can be saved by using a thread file on it (metric 1.0 thread) - those threads are really too soft & I use the file to dress the threads a LOT here at the shop making sure all threads are well cleaned before inserting tool is necessary, as well as being sure that the puller is screwed all the way in to catch as many threads as possible

if you have the clutch off, that shaft can be pulled thru clutch-side bearing as cases come apart
 

SomeGuy

New Member
Nov 22, 2015
20
1
1
Michigan
@Crassius

Seeing that I don't have any puller to use now, I don't see any way to get the drive sprocket off now. Would hammering the clutch shaft from the clutch side work or destroy things?

SomeGuy
 

Kioshk

Active Member
Oct 21, 2012
1,152
10
38
Connecticut
You say you "don't have any puller to use now", did you throw it out? If you have the clutch-gear off, you CAN knock the shaft out towards the drive-sprocket. If you still have the puller, screw it onto the clutch-side of the shaft and knock it out with a hammer. If not, I recommend placing a wooden buffer between the shaft and the hammer. This will knock the entire assembly out the left-side (spring, shaft, bearing, and sprocket).
 

SomeGuy

New Member
Nov 22, 2015
20
1
1
Michigan
To clarify regarding the puller tool please refer to the image I posted above. It has welds all over the threads so that's why I said I don't have a tool LOL

Anyways, I got the casing split! Now I just need to find a way to get the crankshaft seals out safely so I can replace them. Any tips?

SomeGuy
 

Kioshk

Active Member
Oct 21, 2012
1,152
10
38
Connecticut
Oh! LOL! WOW! I missed that one!

Anyway, if you aren't replacing the seals with NEW ones, you could just leave them alone; no need risking damage. Otherwise, you can pry them out with a flathead.
 

Kioshk

Active Member
Oct 21, 2012
1,152
10
38
Connecticut
HOLY MACKEREL! I just saw your drive-sprocket too...be sure to grind off that crap before you ride; it'll surely affect the chain seating.
 

crassius

Well-Known Member
Sep 30, 2012
4,032
158
63
USA
You say you "don't have any puller to use now", did you throw it out? If you have the clutch-gear off, you CAN knock the shaft out towards the drive-sprocket. If you still have the puller, screw it onto the clutch-side of the shaft and knock it out with a hammer. If not, I recommend placing a wooden buffer between the shaft and the hammer. This will knock the entire assembly out the left-side (spring, shaft, bearing, and sprocket).
what he said