Spark plug Spark plug gap Squish Ideal 0.9mm (Between 0.85mm -1mm) Head nut torque 18 ftlbs Engine oil (gearbox and clutch) type: Light Gear Oil Engine oil 800ml on an …
Settings for MZ racing engine
Removal of head, barrel and piston
This procedure is to be carried out when doing any between race meeting inspection / ring change and strip down of the engine. Remove spark plug Diagonally undo head nuts …
Piston removal and small end inspection
(between meetings or at track) Place blue roll or clean rag around con rod at crank case mouth to stop any dropped items going in to the crankcase. See photo …
Removal of Ignition
Required 2 Blocks 1” thick wood and metal bar Place bar through small end eye (no bearing) Place blocks of wood either side of head blot’s see photo below Turn …
Primary drive cover removal
to enable access to clutch and strip down Remove 3 bolts and remove end cover of the clutch operating system place drip tray underneath Remove clutch mechanism locking plate and …
Clutch removal
MUST be a puller with crank over fitting sleeve. Clutch Puller If no fitting sleeve or Puller used with a point that does into the center of shaft there is …
Splitting Casing
Undo all 14 crack case screw Tap right hand side away from left This may require heat on crank area Right hand case Left hand case with crank and gear …
Gearbox check
Set up on 4” block as photo Put into 3rd gear to check dog penetration it should be flush with penetrated gear (1st) Remove Neutral Holder Ball and spring (from …
Crank removal
As with crank split Heat and remove from the left case Remove main bearing oil seals replace every rebuild Remove main bearing oil splash shield by removing circlips on out …
Clutch Rebuild
– Based on a Tony Holmshaw (TH) clutch Remove from crank and place on bench Undo bolts on face of clutch one turn on each bolt doing every other bolt. …
Engine rebuild
Fit Crank oil seals Lube seals with 2-stroke oil Special mandrel for oil seals to stop damage to the seals Tap in to place crank case evenly use blunt drift …
Fit Clutch
Large washer 1st with recesses facing crank case Then needle roller bearing Primary drive / clutch center Washer with recesses facing crank case Clutch on Fit puller on clutch with …
Fitting Barrel, Piston & Head
Re fit studs (if removed) Double Nut top of stud and tighten from top nut repeat for all 4 studs Fit piston Lubricate well with 2 stroke oil Small end …
