Vespa crankshaft installation

Next install the Flyside Bearing into the case on this Model it is a two part Bearing one half goes into the case and the other on the Crankshaft. Apply a thin layer of Grease. Heat up the Case. Use the Punch for the Flyside Seal and Bearing. Gently Tap it in. Remember there are TWO of them. The Best way to install them is to apply a thin layer of Grease to each side. Use a Flat Head Screwdriver the guide them all the way in.

Get the Kick Start Quadrant and Spring ready. It is a good idea to test fit the lever before you install it, this could save you a headache later. Also inspect the teeth. Also inspect the other side to make sure there are no dents dings or other defects. This is the Tab. Install the Spring. Now Hold the Kick Start Quadrant all the way to you right and twist the spring to the left until the tab on the top fits into the Slot on the Kick Start Quadrant. This is what it should look like. Get your Engine Stand out.

Put the other side of the Engine Case into the Stand. Install the Oil Sling. It can only go in one way. Push the Spindle slightly in just enough to hold it up You still have to install the Needle Bearings. Begin by liberally applying Grease to the Race on the Spindle. Depending on your model you should have either 21 or 24 of these Grease your finger so you will be able to pick them up easier. Start to put them in. Once they are all in push the Spindle all the way in. Spin the motor around.

It lines up with a slot on the Spindle. Next install the Nut 13mm. Now bend the tabs over the nut to lock it on place. Grease the Rear Hub Bearing. Slide it in If you need to you can use the old one to tap it in but usually these slid right in by hand. Install the Circlip. Now install the Drive Shaft Slide it in as far as you can by hand. Use the Crank Installer tool. Slide the sleeve over the tool. Screw it onto the Drive Shaft and tighten the nut while holding the tool still.

Now install 4TH Gear. And Finally 1ST. Now install the Shoulder Washer when you rebuilt the gear stack you would have decided the correct size. Now install the circlip. Heat the Case. Heat it some more. Place the Main Bearing evenly into the hole. Use the Punch Tool for the Clutch Side. Tap it in DON'T beat the crap out of it there is a circlip on the other side that you can break out of its recess if you do this you ruin the case Tap it a little check to other side, Tap it a little check the other side, ect Moving on the Crankshaft Install the Crankshaft Wedge.

Grab the Inner part of the Fly Side Bearing. Grab it with the Channel Locks. It should slide right on If you need to you can use part of the Crank Installer to tap it on. Grease the outside of the Clutch Side Seal. Grease the clutch side of the Crankshaft the shorter side. At this point, lightly tap the bearing race on the crank. Heating the race will aid in this process.

Make sure that the flywheel side crank web is fully supported or you will put stress on the crank pin and possibly distort a nice new crank. This race should not touch the flywheel, but be spaced of by about 0. Below is the race location on a new crank and the clearance on a dead crank. Before you install the crank, grease the lip of the clutch side oil seal so it is not damaged by the installation. Getting the crank into the main bearing race is a very tight fit.

The trick I use is to exploit the fact that metal contracts and expands at different temperatures. I throw the crank in the freezer for a couple of hours and either put the clutch side casing half in the oven make sure all flammable liquids are thoroughly cleaned form the casing or heat up the main bearing with a blow torch. Either way be sure that the temperature is low enough so it does not damage the clutch side oil seal!

With the crank and bearing being at such different temperatures they should drop together with only your hands force. If not I have used the method below to draw the crank into the main bearing:. Use the flywheel side bearing you just removed as a spacer and make sure it fits directly over the inner race of the main bearing.

Lastly, thread the clutch nut onto the crank and have someone hold the clutch side web of the crank. Unless it is a very tight fit it shouldn't be too hard to stop the crank from turning. As you tighten the nut with a clutch nut tool the crank will be drawn through the bearing.

Dropping the engine Flywheel Removal. Above is a shot of the crank correctly seated. The important part to note is that the crank web lip fully seals and unseals the intake hole in the casing.

Make sure the lip of the crank web drops down into the groove in the casing. If you look at the shoulder of the crank against the clutch side of the main bearing it may not be totally flush, but as long as the lip is in the groove the crank is well installed. The crank is all furry with ice condensation because it was frozen before I installed it.

If you use this method and don't plan to use the engine the same day as the rebuild, spray the crank with WD40 so the ice doesn't melt and start to rust the crank or bearings. Installing a crank This section assumes that you have already split the casings and removed the old crankshaft from the main bearing.

If not I have used the method below to draw the crank into the main bearing: Use the flywheel side bearing you just removed as a spacer and make sure it fits directly over the inner race of the main bearing.