sean01
Legend Spanner Spinner
ok i got this info a while back and tested it out.. thanks to FPM for pointing me in the right direction.. and thanks Clayton from QBR in Lawnton for supplying a couple of crf50 idle gears..
i done 2 of these, mine is yet to be installed and one is in an LXR with 64mm TB BBK and V2 head, been in there since before the black duck valley ride day and still going strong..
quick note tho.. i don't expect these to be a permanent fix but they definitely slow down the failure rate of these china clutches
ok what you need is
standard china engine clutch basket
genuine crf50 or 70 clutch idler gear (ebay usa usually has them)
6 x m6x1x12mm long unbreako bolts (allen key headed) 10mm will fit, 15mm need cutting down
angle grinder with metal grinding disk
steel punch about 5mm in diameter
6 or 7mm drill bit
m6x1 tap
thread lock loctite
ok
grind the heads of the rivets off the china clutch basket but try not to damage the plate.
next remove the plate without bending it and remove the old rubbers.
then punch the remaining rivets out of the clutch basket.
now depending how sharp your tap is the holes may need drilling to suit an m6 bolt.
tap the 6 holes all the way thru.
degrease and clean the clutch basket..
get the crf idler gear and do the same with the rivets, remove the plate and pull the rubbers out..
install the rubbers into your china clutch basket (make sure there clean)
now the plate will need drilling so the m6 bolts will go through them. make sure you debur the holes too.
ok ready to assemble the plate and bolts... make sure you use loctite on all the bolts and make sure the bolts aren't too long and poke through the other side as it will interfere with the inner clutch hub.
the bolts i used needed a couple of mm ground off them so it cleared the kicker gears.. you need a good couple of mm clearance as the clutch wobbles a bit when running..
and there you have it, you now have a serviceable clutch.
i done 2 of these, mine is yet to be installed and one is in an LXR with 64mm TB BBK and V2 head, been in there since before the black duck valley ride day and still going strong..
quick note tho.. i don't expect these to be a permanent fix but they definitely slow down the failure rate of these china clutches
ok what you need is
standard china engine clutch basket
genuine crf50 or 70 clutch idler gear (ebay usa usually has them)
6 x m6x1x12mm long unbreako bolts (allen key headed) 10mm will fit, 15mm need cutting down
angle grinder with metal grinding disk
steel punch about 5mm in diameter
6 or 7mm drill bit
m6x1 tap
thread lock loctite
ok
grind the heads of the rivets off the china clutch basket but try not to damage the plate.
next remove the plate without bending it and remove the old rubbers.
then punch the remaining rivets out of the clutch basket.
now depending how sharp your tap is the holes may need drilling to suit an m6 bolt.
tap the 6 holes all the way thru.
degrease and clean the clutch basket..
get the crf idler gear and do the same with the rivets, remove the plate and pull the rubbers out..
install the rubbers into your china clutch basket (make sure there clean)
now the plate will need drilling so the m6 bolts will go through them. make sure you debur the holes too.
ok ready to assemble the plate and bolts... make sure you use loctite on all the bolts and make sure the bolts aren't too long and poke through the other side as it will interfere with the inner clutch hub.
the bolts i used needed a couple of mm ground off them so it cleared the kicker gears.. you need a good couple of mm clearance as the clutch wobbles a bit when running..
and there you have it, you now have a serviceable clutch.
That's just how I do 'em. One Chinese headache solved, a few more to go...