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+Engine Build Database
Engine Assembly Part 1 - Large Frame
 
  • Start with the Flywheel side of the engine case
  • Using the torch Heat up the case (for about a minute or two at the Selector Rod Bearing
  • DON'T BE SCARED YOU WONT MESS IT UP

 

 
 
  • 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
 
 
  • 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
 
 
 
 
  • Inspect the Kick Start Quadrant for any damage at the splines where the Kick Start Lever attaches.
  • 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
 
  • Apply a thin layer of Grease
 
  • Slide it in (It should Slide in EASY)
  • If there is any resistance it may be Bent in which case REPLACE it
 
 
  • NOTE: This hole accepts the tab on the Spring
 
  • This is the Tab
 
 
 
  • This is what it should look like
 
 
  • Put the other side of the Engine Case into the Stand
 
 
  • It can only go in one way
 
 
 
  • 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
 
  • It may take you a few tries just stick with it
  • Make sure you keen an eye out it you drop one
  • If you do drop any clean them off all that grease will make EVERYTHING stick to them (bearings + dirt = bad)
 
  • 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
 
  • This is what it should look like
 
 
 
  • 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

 

 

 

 

 

  • Slide the sleeve over the tool
 
  • Screw it onto the Drive Shaft and tighten the nut while holding the tool still

 

 

  • 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
 
  • Now install the Main Bearing on the Clutch Side
  • First a little Grease

  

  • Heat the Case
 
  • Heat it some more
 
 
 
  • 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
 
  • Apply a thin layer of Grease
 
 
  • Heat it up (NOT TOO MUCH)
 
  • 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 clutch side of the Crankshaft (the shorter side)
   
  • Also Grease the Seal (this will help it Crankshaft slide in without popping the spring out of the Seal
 
 
 
 
  • Use a Rubber Band to keep the Connecting Rod from binding up on the Case half
 
  • Tighten the Nut while holding the tool
 
 
 
 
  • A little dab of Grease in a few spots will help it stay in place
  
  • Inspect the Kick Star Gear for worn teeth
  • If you have the motor apart I would REPLACE it
 
  • Grease the Cush Drive
 
 
 
 
  
 
  • You don't need to put the bolt in at this point
 
  • NOTE: This Dowel....................
 
  • ................lines up with this hole
 
  • Grease
  
  • Grease
 
 
  • Now tap it the rest of the way together with a rubber hammer
 
  • and here 
 
 
 
 
 
  • Each one has a Flat Washer, Lock Washer, and Nut in that order
  • Start in the middle making an x pattern and work your way around tightening them more each time the final torque setting should be
     
  • Don't forget the Gear Cable Holder
  • It goes on the long case bolt that probably didn't come out when you took the motor apart
 
 
 
 
 
  • Line them up and slide it on.
  • You may need to spin the CushDrive with a screwdriver to get the teeth to mesh with the clutch teeth.
   
      
 
 
 
   
  
 
 
 
  • Start it on the bottom
 
  • Use a Screwdriver to push the Retaining Clip down and it will slide in
 
 
 
 
  
 
 
 
 
  • NOTE: The Piston has an arrow stamped on it that will face the Exhaust port or DOWN.
 
  • Put the Wrist pin through the piston then through the Small end Bearing
  • It should slide in easy with very little resistance (A little two stroke oil will help you alot put some on the pin before you start.
  
  • Install both Circlips to lock the Wrist pin in
 
 
  • Coat the inside of the Cylinder with a bit of 2 Stroke
  • Slightly pinch the Piston Rings (they fit into two grooves on the Piston) to allow the Cylinder to slide over
 
  • Once you get past the Rings slide it the rest of the way on.
 
  • Now you are ready for the Head