HOW-TO: Crankcase internals check, parts removal

this is the second time im writing this becasue the first time i did it i didnt log in and everything got wiped. fml

to split case see Volcoms helpful how to thread

Step 1: make a clean work space



Step 2 : spin the gears on mainshaft and layshaft looking for chips in teeth worn out parts scuffed metal and scoring. spin crank slowly and inspect rods and sproket.


green dots = 4 bearings. the small bearing on the main shaft is a needle bearing. dont loose needles, red lines are 3 circlips,

Step 3: lift out mainshaft, careful not to loose 1 circlip. spin remaining gears on layshaft that are now free. listen for whirring sounds. (bad bearing) -drewpy

step 4: hold mainshaft and spin free gears (step 3)

step5 : lift out layshaft watch for 2 circlips, inspect journals for scoring ect.




step 6: remove oil pump assy. 3 allen bolts on the clutch side on the case beside the crank shaft



step 7 : remove oil baffle plates by pressing down on them while sliding the transverse rod out the clutch side of the case


Step 8 : flip case over remove the oil strainer cover and screen (small square cover) pull out screen and clean, note the stamped arrows on the cover and screen when reassembling. points to front of engine.

Step 9: clean the inside of the case. inspect main bearings (u journals that hold the crank shaft) i didnt replace mine because i dont have a micrometer or new ones so i just made sure there was nothing obviously wrong.


Step 10: if you need to replace bent clutch forks or shifting assy parts do so now

step 11: reassemble in the reverse order.. hopfully you Bagged and tagged everything


clean mating surface on 2 halves of cases. im not sure if this needs rtv gasket sealer or anything. does anyone know? mine had some residue that i scraped off witha razor blade.

happy trails

nice one, I use wellseal, yamabind the the official recommendation

How many circlips are there suposed to be in total? Im trying to put mine together but i only have 4, 2 smaller and 2 larger. It looks like there is room for 8. Not sure if Ive lost some while tearing it apart. Thanks.

Now for the extra bonus points, I have to do all that, and seperate the crankshaft gears, and put them onto a new one. I am sure the directions are inthe supplemental manual, (I just haven't looked) Looks Good! I will pratice it next month!

Benj said:

How many circlips are there suposed to be in total? Im trying to put mine together but i only have 4, 2 smaller and 2 larger. It looks like there is room for 8. Not sure if Ive lost some while tearing it apart. Thanks.

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If you are referring to the mainshaft/layshaft split circlips, there should only be four. The other ends are held in by the bearings, they have a built in ring on them already that fits into the crankcase slots.