FZ 750. Front sprocket oil seal. Can I replace without splitting the engine?

5.0L and 5.7L Engines To Remove:

1. Remove the crankshaft balancer.
2. Drain the cooling system.
3. Remove the water pump.
4. Drain the engine oil.
5. Remove all engine oil pan fasteners except two nuts at rear of engine.
6. Separate the engine oil pan from the front cover.
7. Disconnect the crankshaft position (CKP) sensor wire.
   
   
8. Remove engine front cover.
   
   
9. Pry the oil seal from the front cover.
10. Inspect the front cover seal area and crankshaft balancer seal area for damage.
    
    
11. Rotate the crankshaft until the timing marks on the crankshaft and the camshaft sprockets are aligned.
12. Remove the crankshaft position sensor reluctor ring.
    
    NOTE: Free play on the slack side of the camshaft timing chain must measure less than 0.43 inch (11Mm) or timing chain and sprockets must be replaced.
    
13. Remove the camshaft sprocket bolts.
14. Remove the camshaft sprocket.
15. Remove the camshaft timing chain. NOTE: Do not turn the crankshaft assembly after the timing chain has been removed in order to prevent damage to the piston assemblies or the valves.
    
    
    
16. Remove the crankshaft sprocket using J 5825-A.
17. Remove the crankshaft balancer woodruff keys (if required).

To Install:

1. Install the crankshaft balancer woodruff keys into the crankshaft.
2. Align the crankshaft sprocket keyway with the crankshaft balancer woodruff key. WARNING
   Wear eye protection when installing crankshaft sprocket.
   
   
   
3. Use J 5590 to install crankshaft sprocket.
4. Install the camshaft sprocket and camshaft timing chain.
   
   
5. Ensure that the crankshaft sprocket alignment mark is in the 12 o'clock position and the camshaft sprocket alignment mark is at the 6 o'clock position.
6. Install the camshaft sprocket bolts and tighten the camshaft sprocket bolts;
   • Torque to: 18 ft. lbs. (25 Nm)
7. Install the crankshaft position sensor reluctor ring until completely seated against crankshaft sprocket. NOTE: The composite type engine front cover and seal must not be reused. Always install a new engine cover with a new seal.
   
8. Install new engine front cover and bolts.
   • Torque bolts to: 106 in. lbs. (12 Nm)
9. Clean sealer from corners of oil pan gasket where it meets the engine front cover.
   
   
10. Apply a 0.196 in (5 mm) bead of adhesive, GM P/N 12346141 or equivalent, 1.0 in (25 mm) long to the engine front cover to engine block junction.
11. Install oil pan bolts.
    • Torque bolts to: 106 in. lbs. (12 Nm)
12. Tighten oil pan nuts.
    • Torque bolts to: 18 ft. lbs. (25 Nm)
13. Connect the crankshaft position sensor wire.
14. Install the water pump.
15. Install the crankshaft balancer.
16. Fill the engine to the proper level with oil.
17. Fill the engine to the proper level with coolant.
18. Test drive the vehicle to confirm the repairs.

I only found a front crankshaft seal replacement not the whole crankshaft: Front Crankshaft Seal REMOVAL AND INSTALLATION 1.5L (5E-FE) Engine Tercel NOTE: The front oil seal can be removed from the engine without removing the oil pump.

1. Disconnect the negative battery cable from the battery. On vehicles equipped with an air bag, wait at least 90 seconds before proceeding.
2. Remove the front covers and the timing belt.
3. Remove the crankshaft timing belt sprocket. WARNING
   When removing the front seal, be extremely careful not to damage the crankshaft.
   
4. Using a knife, cut off the oil seal lip.
5. Tape the end of a flat bladed tool to avoid damaging crankshaft. Pry out the oil seal using the taped end of the tool.
6. Inspect the oil seal riding surface on the crankshaft for signs of wear or damage. To install:
   
7. Wipe the seal bore with a clean rag.
8. Apply multipurpose grease the lip of a new oil seal.
9. Drive the oil seal into place using tool SST 09309–37010 or an equivalent seal installer tool. Make sure the seal surface is flush with the oil pump case edge. Work from the front of the cover. Be extremely careful not to damage the seal.
10. Install the sprocket without disturbing the Woodruff key.
11. Install the timing belt and front covers.
12. Connect the negative battery cable to the battery.
13. Start the engine and check for leaks

The manual on the 750 says put new seals on the crank as you install it, and I believe they have a locating lip on the seal that fits in a groove in the cases. which means a split.

I have trimmed the lip off the seal, and installed them with loctite master gasket, the old seal is hard to remove due to the lip

if you are lucky there is a clip behind the front sprocket remove both then pop the seal out drain gear box oil first though. if not which i think is most probable the engine will need splitting if you are good with spanners it is quite easy being a 2 stroke .in brief remove engine remove bore and carb in one lump remove sprocket gear lever split g-box .seal up push old seal out, from outside in, fit new then reverse prosses. a good manual will help.

The oil seal on the sprocket shaft has probably gone bad. Remove the sprocket then clean the shaft to aid in removing the old seal. A screw driver and small hammer is used to pry the outer edge of the seal inward. Realize that you will butcher the old seal in the process of removal. The only other way to remove the old seal is to pull the engine and split the center case.

If you go to www.bikebandit.com/
you can see a blow up of the parts.
You need to remove the chain, then the snap ring at the sprocket, and pull out the center bushing, and there is two O-rings inside of that. You should be able to fix this without splitting the case.

It is a chain and its not the easiest but it could be worse.It is as follows:
1.9L SOHC Engine

1. Before servicing the vehicle, refer to the precautions in the beginning of this section.
2. Drain the engine oil.
3. Remove or disconnect the following:
   • Negative battery cable
   • Right front wheel and splash shield
   NOTE: Place a 1 in. x 1 in. x 2 in. long block of wood between the torque strut and cradle to ease removal and installation of the torque engine mount.
   • 3 right side upper engine torque axis to front cover nuts and the 2 mount to midrail bracket nuts, allowing the powertrain to rest on the block of wood
   • Drive belt, tensioner and pulley
   • Power steering pump attaching bolts and set the pump to the side with the lines still attached
   • A/C compressor from the bracket and set aside with the lines attached
   • Camshaft cover
   • Using a strap wrench or a piece of wood wedged between the damper spoke and the lower side of the engine front cover, hold the damper and remove the bolt. With a suitable 3-jaw puller and the slots cast into the damper, pull the crankshaft damper/pulley assembly from the crankshaft.
   • Install the special oil seal replacement tool SA9104E, to be sure the front crankshaft timing sprocket is held firmly in place and prevent guide damage. Install with the flat side towards the crankshaft sprocket.
   • Remove or disconnect the following:
     • Front 4 oil pan bolts and cut the seal away from the front cover
     • Front cover bolts and carefully pry the cover away from the cylinder block at the pry location tabs, which are provided. Remove the cover from under the hood or through the wheel well
     • Front cover oil seal from the cover
     NOTE: During timing chain and sprocket removal, position the crankshaft 90 degrees past Top Dead Center (TDC), to be sure the pistons will not contact the valves upon assembly.
     
   • Carefully rotate the crankshaft clockwise so the timing mark on the crankshaft sprocket and keyway align with the main bearing cap split line (90 degrees past TDC).
   • Remove or disconnect the following:
     • Timing guides and tensioner
     • Camshaft sprocket bolt, using a 7⁄8 in. (21mm) wrench to hold the camshaft. Then, remove the timing chain and camshaft sprocket
     • Crankshaft sprocket
     To install:
     
   • Inspect the chain for wear and damage. Check the inside diameter of the chain, it should be no more than 16.77 in. (426mm). Inspect the chain guides for wear or cracks and the timing sprockets for teeth or key wear. Replace components as necessary.
   • Verify that the crankshaft keyway is positioned 90 degrees clockwise past TDC (keyway at 3 o'clock). The keyway should align with the split between the bearing cap and engine block.
   • Bring the camshaft up to No. 1 TDC by loosely installing the sprocket and rotating the sprocket until the timing pin can be inserted. The camshaft contains wrench flats to assist in turning the shaft. The dowel pin should be at 12 o'clock when the camshaft is at TDC.
   • Install the crankshaft sprocket, then rotate the crankshaft counterclockwise 90 degrees up to No. 1 TDC (keyway at 12 o'clock).
   • Position the chain under the crankshaft sprocket and over the camshaft sprocket. The timing chain should be positioned so that 1 silver link plate aligns with the reference mark on the camshaft sprocket and the other aligns with the downward tooth (at the 6 o'clock position) on the crankshaft sprocket. The letters FRT on the camshaft sprocket must face forward, away from the cylinder head and excess chain slack should be located on the tensioner side of the block.
   • Install or connect the following:
     • Timing pin to verify proper alignment of the camshaft and sprocket. Torque the sprocket bolt to 75 ft. lbs. (102 Nm).
     NOTE: Do not allow the camshaft retaining bolt to torque against the timing pin or cylinder head damage will result.
     • Timing chain guides with the words FRONT facing out. Install the fixed guide first and verify the chain is snug against the guide, then install the pivot guide. Torque the bolts to 19 ft. lbs. (26 Nm) and verify that the pivot guide moves freely
     • Retract the tensioner plunger and pin the ratchet lever using a 1⁄8 in. No. 31 drill bit inserted in the alignment hole at the bottom front of the component
     • Tensioner. Torque the bolts to 14 ft. lbs. (19 Nm), then remove the drill bit
   • Make one final check to verify all components are properly timed, then remove all timing pins.
   • Install or connect the following:
     • Seat a new front cover oil seal using the installation tool with a press
     • If the engine front cover casting or assembly is replaced, the 3 torque axis mount studs should also be replaced. Torque the new studs to 19 ft. lbs. (25 Nm).

1.9L (DOHC) Engine

1. Before servicing the vehicle, refer to the precautions in the beginning of this section.
2. drain the engine oil.
3. Remove or disconnect the following:
   • Negative battery cable
   • Right front wheel and splash shield
   NOTE: Place a 1 x 1 x 2 in. (25 x 25 x 51mm) block of wood between the torque strut and cradle to ease removal and installation of the torque engine mount.
   • 3 right side upper engine torque axis to front cover nuts and the 2 mount to midrail bracket nuts, allowing the powertrain to rest on the block of wood
   • Drive belt, tensioner and pulley
   • Power steering pump attaching bolts and set the pump to the side with the lines still attached
   • A/C compressor from the bracket and set it to the side with the lines attached
   • Camshaft cover
4. Using a strap wrench or a piece of wood wedged between the damper spoke and the lower side of the engine front cover, hold the damper and remove the bolt. With a suitable 3-jaw puller and the slots cast into the damper, pull the crankshaft damper/pulley assembly from the crankshaft.
5. Install the special oil seal replacement tool SA9104E or equivalent, to be sure the front crankshaft timing sprocket is held firmly in place and prevent guide damage. Install with the flat side towards the crankshaft sprocket.
6. Remove or disconnect the following:
   • Front 4 oil pan bolts and cut the seal away from the front cover
   • Front cover bolts and carefully pry the cover away from the cylinder block at the pry location tabs, which are provided. Remove the cover from under the hood or through the wheel well
   • Front cover oil seal from the cover
   NOTE: During timing chain and sprocket removal, position the crankshaft 90 degrees past top Dead Center (TDC), to be sure the pistons will not contact the valves upon assembly.
   
7. Carefully rotate the crankshaft clockwise so the timing mark on the crankshaft sprocket and keyway align with the main bearing cap split line (90 degrees past TDC).
   • Timing guides and tensioner
   • Camshaft sprocket bolt, using a 7⁄8 in. (21mm) wrench to hold the camshaft. Then, remove the timing chain and camshaft sprocket
   • Crankshaft sprocket

where is leaking oil from....behind the front sprocket??

if so your chain is TOO tight

if this is your problem, replace the output shaft seal and check drive line for abnormal wear before readjusting chain tension.

240mls per leg

a good 10w40 oil..if you dont know what type was used before then i would flush the engine then put the new oil in