How to rebuild a v1:

Tools you will need:

* Zip ties

* Allen wrench set (5mm for sure)

* 10mm socket and appropriate ratchet

* Spark plug wrench/socket

* Puch/Minarelli clutch puller

* Piston stop (OR ROPE)

* CEV (or Bosch) flywheel puller

* Flat head screw driver

* Needle nose pliers

* Rubber mallet

* Heat gun (or a torch)

* Oven

* A range of box wrenches

* Circlip pliers

* 7mm socket (optional)

* (Factory) Case splitting tool

* Old seat post

Bearings and seals needed:

* 2 6203 non-shielded bearings

* 2 6202 non-shielded bearings

* 2 17 X 35 X 8 seals (or 17 X 35 X 7)

* 3 15 X 24 X 5 seals

* New case, clutch cover, base and head gaskets

What I like to do before I start to split the case is to remove the bearings from the packaging and put them in my freezer so they'll shrink a little bit (and by a little bit, I mean a very small amount).  It will help the bearings go into the case much easier.

Step 1: Clutch removal

- Remove lower screw on face of clutch cover

- Drain oil from transmission into a pan

- Remove clutch cover with 5mm allen wrench

- Remove starter clutch retaining clip

- Remove starter clutch plate

- Remove spark plug from head

- Insert piston stop (or rope)

- Depending on your v1 your clutch nut is going to be right hand or left hand thread.  For the most part all of my v1's have been left hand thread, meaning you turn the wrench to the RIGHT to loosen the clutch nut.  Loosen the clutch nut and take it off.

- Remove the washer and set it aside with the clutch nut.

- Get your clutch puller out.  Do not use the allen bolts it came with, instead use 2 of the clutch cover screws as they are softer and will not strip the clutch hub!  Thread the center bolt all of the way out.  Position the clutch puller so the screws go into the clutch.  Do NOT tighten it so they bottom out on the clutch bell, if they do --- back them out a few turns.  Now thread in your center bolt so that it is perfectly straight on the crank.  Tighten everything down and your clutch should pop off.  Sometimes the clutch shells bend, if that happens you'll have to get a new clutch shell or take it apart and bend it back.  Every once in a while you will find a clutch that just won't come off.  I've had to weld my puller bolts to the clutch before in order to get it off.  That's a whole different story.  Now assuming your clutch is off, proceed to the next step.

- There is a circlip under the clutch.  Remove the circlip with the circlip pliers.

- Pull the clutch bell off.  Sometimes the bushing gets stuck on the crank.  If that happens hit it with your heat gun or torch for a minute or two and then it should slide off.

- There are shims underneath and above the clutch bell, keep them in their respective places along with the circlip.  At this point I zip tie everything together so I know the order of which things go!

Step 2: Remove the main gear

- With your circlip pliers remove the clip that is on top of the crown nut

- Remove shim underneath circlip

- Pull off crown nut

- Remove circlip

- Remove shim

- Remove main gear

- Zip tie everything together in the order it was removed

Step 3: Remove ignition (keep all screws/nuts together!)

- Remove outer fan shroud

- With a phillips screw driver CAREFULLY remove the 4 screws holding the fan on to the flywheel.  These can be very easy to strip if they have never been taken off.  Be careful.

- Remove the back fan shroud

- With a 15mm socket, loosen the flywheel nut and take it off.

- Thread your flywheel puller in to the flywheel.  Tighten it down and pull the flywheel off.

- Remove woodruff key and set it aside where it won't get lost

- Remove the screws holding the stator to the case

- Pull the stator off and set it aside

Step 4: Top end removal (make sure carburetor is not on prior to this step)

- With a 10mm socket remove the 4 nuts holding the top end down.  Place nuts where they will not get lost.

- Remove head

- Throw away head gasket (do not reuse)

- Carefully pull the cylinder off

- Remove the wrist pin clips

- Remove the wrist pin

- Set piston aside with the cylinder and head

- Optional step: Remove cylinder studs (tighten two of the stud nuts together and loosen the bottom one to remove each stud, repeat 4x)

Step 5: Sprocket removal

There are a few different ways to do this but I find that this is the easiest way to do it.

- Jam a 7mm socket in between the teeth of the sprocket and the case

- With a 17mm wrench remove the nut holding the sprocket on.  It may need a few taps with a mallet, sometimes they are on there pretty tight.

- Remove the sprocket.  If you have trouble removing it, stick a wrench underneath it and lightly pry on it until it pops off.

Step 6: Case splitting

- Remove the 11 allen bolts that hold the case together.  Make sure you remove them all, this is VERY important.

This is where things can go wrong.  I would highly suggest you put your case in the oven for about 15 min @ 300deg at this point.  It will make this step MUCH easier.

-  Grab your case splitting tool.  Loosen the middle bolt.  Thread the 3 bolts into their respective places on the case (the 3 holes on the outside of the casing on the ignition side of the case).  Tighten them down and start threading the center bolt in to the end of the crank.  Go very slowly and check the case to make sure it is separating evenly.  If it is not, do not keep tightening the case splitter center bolt.  Take a flat head (or a tire lever) and slowly pry on the side of the case that is not splitting.  Be extremely careful.  I like to give it a few solid whacks with a mallet to loosen it up.  You may have to repeat this process a few times before you are able to pull the case half off evenly.  I like to split the case with it horizontal so the shims have a much higher chance of staying in place.  

Once the case is mostly split I like to grab a flashlight and shine it inside the case.  Look for any shims that may be ready to fall off of their shafts.  Push them back into place and continue splitting the case.

 - At this point you should have the case split.  Take extreme care to not lose ANY of the shims. Sometimes they stick to the case so I ALWAYS check the cases for any shims that are stuck and then return them to their specific spots.  I always put them back in their spots after I remove the shafts so I know where they go!

- Remove the pedal crank (heat up the case and whack it with a mallet if it won't come out).

- Take a punch or a phillips screwdriver and tap the output shaft out of the bearing.  

- Take a piece of wood and place it against the crankshaft.  Tap on it until it pops out of the bearing.  There is a shim that goes on the ignition side of the crank.

- Remove the gear cluster (shim on both sides of it!)

- Set everything aside and make sure no shims are out of place.  TAKE YOUR TIME!

Step 7: Bearing removal

Sometimes when the case is being split one or two of the bearings will get stuck on the shafts.  You will need a bearing puller to pull them off of the shafts, do not try and use a 3 jaw puller or anything stupid like that.  Use the correct tools.

- Take a flat head and gently pry the seals out of the case

- The easiest way to remove the bearings is to take an old seatpost and with the small end facing the outside of the case, I just whack on bearing until it comes out.

- The output shaft bearing is a little trickier.  I generally take a flat head and hit it with a mallet to pop the bearing out.  Just be careful.

- Be mindful of the shim that is between the output shaft bearing and the case! It is necessary, do not lose it! Set it aside in a safe place.

- Put output shaft in freezer!

Step 8: Bearing installation

I highly suggest cleaning the hell out of your cases first, before you complete this step.  What's the point in rebuilding a motor if you have a bunch of nasty shit floating around in your case that will just gunk up your new bearings? If the bearings do not want to sit in the races then you must gently remove them and heat the cases up to a higher temperature.  They can be finicky! 

- Place both case halves in the oven @ 350 for 15min

- Remove the ignition side case half from the oven

- Take one 6203 bearing from the freezer and gently place it in the case

- Place output shaft shim in case

- Take one 6202 bearing (for output shaft) from the freezer and gently place it in the case

- The bearings should drop right into the case with no issues!

- Put the ignition side case half BACK in the oven

- Remove the transmission side case half and install the bearings as previously mentioned

- Remove the ignition side case half and taking great care not to have the bearings fall out, tap the output shaft (sprocket side) into the output shaft bearing.  Make sure it is seated flush, all the way.

- Take your heat gun or torch and heat up the ignition side crankshaft bearing for a minute or two.  Install the crankshaft into that bearing.

Step 9: Put it all back together

- Install gear cluster with shims in proper placement

- Install pedal shaft and make 100% sure that the "claw" is sitting on the post.  This is extremely important.

- Put transmission side case half back in the oven for 10min @ 350deg

- Take your case gasket and cover it in oil

- Lightly tap the 3 bushing pins almost all the way out of the case.  They should be barely coming out on the gasket side.

- Install case gasket , being mindful that it should be FLAT and not have any tears

- Take the transmission side case half out of the oven

- Quickly take that half and slide it on to the exposed shafts.  Be very very careful.  There will be a point where it most likely will not press together all of the way.

STOP

- Do not try and press the case together at this point if it binds up!  Take a flash light and look inside the case at the pedal shaft.  Is the claw sitting on the post? If it isn't you will need to finesse it back on with a small flat head and rotating the case around.  Once you get it back on MOVE THE PEDAL SHAFT backwards with a wrench so the claw slides down onto the post!  Proceed to next step ONLY after this has been completed successfully.

- Take a 10mm wrench and put it on the output shaft.  Slowly turn it while simultaneously tapping on the case VERY lightly with your rubber mallet.  Do not force it or you will break the case!  You should start seeing the case come together. 

- At this point start threading in your allen bolts, but if you feel the case binding, loosen them all up (or take them out) and repeat the above step

- Once the case has come together you can pat yourself on the back, but only after you have installed the case bolts, torqued them down and then tapped the bushings back in!

Step 10: Everything else is the reverse of removal!

- Install everything else

- Trim the case gasket that is sticking out of the combustion area, use a flat blade.  Do not mar the gasket sealing surface

Alright, so you're all done... mount it up... fill it with oil and blast to the moon my friend!