Changing the Oil Seal on the Vespa PX
I have had to change the flywheel oil seal on my recently restored Vespa PX. I noticed there was oil leaking from behind the flywheel and thought an old or worn seal would be the culprit, and that it would need to be changed. I wanted to give a quick tutorial on how to rectify the issue, if anyone is stuck on how to do so.
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First of all you will have to remove the engine cowlings. Once you have completed this, you can then remove the flywheel and the stator as the seal sits behind both of these. To remove the flywheel you will need a pulling tool and flywheel holder. You will have to tighten the bolt on the puller to push the flywheel of the tapered crankshaft. The stator can then be removed by undoing a few screws which will remove it from the engine case. Make sure when removing the flywheel and stator, that you mark with a pencil against the engine case where they sat. You will then be able to line these bits back up for timing purposes when you come to put the scooter back together. Once this is done you can then remove the flywheel oil seal.
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To remove the seal you can use a flatheaded screwdriver to pry the oil seal out from behind the crank. Remember to be careful when doing this as you do not want to damage the crank's taper.
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Flywheel seal being removed with screwdriver
Make sure you grease the new seal first before installing. When placing the seal in to the engine casing make sure equal amounts of pressure are applied to each of its sides, so it sits evenly. I normally use a rubber hammer just to lightly tap the engine seal in to place. I then use a lighter tool just to make sure each side is in correctly. This could be something with a plastic end. This then prevents the new seal from becoming damaged which would then mean having to replace it again. The engine can now be put back together.
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Vespa flywheel seal in place
As stated in my previous paragraph, make sure when putting your stator and flywheel back on that you line the pencil markings up with the engine case, so that the timing is correct. You will also need your flywheel holding tool and a socket set to tighten the flywheel.
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I hope this tutorial has been helpful, and I will look to do more of these in the near future.