Jackpiner crank seals

[sbolly]

I need to replace the crankshaft seals on my '72 175cc. Jackpiner. Do I need specal tools? Does the engine need to come out of the frame? Can an average person (me) do this? Thanks for any advice!

 

[skipperclyde]

The magneto side can be replaced with ease with the engine on the bike.  The clutch side requires a major overhaul.  The crankshaft must be removed and the biggest problem is pressing the crankshaft off the small bearing on the clutch side.  Penton had a tool for this.  Teddy and I made our own. I have heard of others driving it out with a hammer and block of wood, but I wouldn't recommend it.  

You will most likely need to modify a gear puller to remove the gear on the end of the crankshaft on the clutch side.  There is very little clearance between the gear and the casing.  I use a 3" puller and have ground down the jaws to fit in the allotted space.

I would also recommend when the cases are split that you use a heavy tape and go around the case and gears to hold the gears, shifting rods and drum in place.  This way when you put it all together it saves the hassle of aligning it all.

When putting the engine back together you will need to have the clutch actuator off.  This allows you to use a small philips screwdriver to align the three shifting rods in the case.  Also pay attention to the spring on the rod from the shifter to make sure it is centered on the "dimple".

After the cases are back together you then replace the small bearing on the clutch side by driving it on with a deep socket.  

Please make sure you have a manual to follow.  I'm sure others will have additional advice.

Good Luck

 

[skipperclyde]

The magneto side can be replaced with ease with the engine on the bike.  The clutch side requires a major overhaul.  The crankshaft must be removed and the biggest problem is pressing the crankshaft off the small bearing on the clutch side.  Penton had a tool for this.  Teddy and I made our own. I have heard of others driving it out with a hammer and block of wood, but I wouldn't recommend it.  

You will most likely need to modify a gear puller to remove the gear on the end of the crankshaft on the clutch side.  There is very little clearance between the gear and the casing.  I use a 3" puller and have ground down the jaws to fit in the allotted space.

I would also recommend when the cases are split that you use a heavy tape and go around the case and gears to hold the gears, shifting rods and drum in place.  This way when you put it all together it saves the hassle of aligning it all.

When putting the engine back together you will need to have the clutch actuator off.  This allows you to use a small philips screwdriver to align the three shifting rods in the case.  Also pay attention to the spring on the rod from the shifter to make sure it is centered on the "dimple".

After the cases are back together you then replace the small bearing on the clutch side by driving it on with a deep socket.  

Please make sure you have a manual to follow.  I'm sure others will have additional advice.

Good Luck