45
...ourprojectbikeisprogressingnicely,
butaswithallgoodrebuilds,occasionally
youneedabreather...andthisisours!For
anumberofverygoodreasonsourproject
bikeisonholdforafewweeks.Asthe
wholepointoftheserieswastoshowan
ordinaryenthusiast–theeditor–doing
theworkratherthanshippingit offtoa
specialist,we’vehadsomeofthedelays
everyoneexperiences,beforereturningto
theITprojectnexttime.Thestorysofar...
mainbearings,leakingforkseals,worn
gearchangeshaftsplinesandaclutch
needingstronghandstooperatethelever.
Actuallythislastoneisalsothetechfeature
hereandinvolvedthehelpofsomeonewith
moreengineeringabilitythanmetodothe
machining.Withoutspoilingthesurprise
ofthetechfeaturetoomuch,it involvesa
Can-Amclutchmodificationaimedatgiving
theeditor’sclutchhandaneasiertimeofit
inenduros.
Thethingis,whileabikeisapartthere
alwaysseemstobeothertaskstoattend
to.Forquiteawhiletheprimarycaseonthe
RotaxenginefittedtomyCan-Amenduro
bikehasleakedoilatanalarmingrateand
thisaspecthasbeenignoredratherlonger
thanit shouldhavebeen;inmydefencethe
casehasbeenonandoffalot,makingsure
thestandardclutchactuatorwaslubricated
properly soit couldperformatitsbest.
Iwasjustabouttogiveuphopewhen
severalsuggestionsformodswereputmyway,
oneactuallyincludedthebitstodothejob...
WiththistaskcompletedIturnedmyattentiontostemmingtheflowofoilout
ofthecase.Rotax’sdiscvalvetwo-stroke
engineisafairly well knownunitandcomes
inanumberofspecifications,dependingon
theintendeduse,butit canbegroupedinto
twomaintypes,thesebeingautolubeand
pre-mix.Intheformer,theprimarycasehas
aseparatecompartmentinit whichhouses
anoilpumpfedfromanexternaloilreservoir
–inthecaseofmyex-militaryCan-Amthis
reservoirformsthetoptubeoftheframe–
whileenginesusingpre-mixoftenhavea
differentcasewithnooilpumpandthetwo
strokeoil ismixedinwiththefuel.
Now,Iwasadvisedbynolessanauthority
thanJeffSmith,whoactuallydesignedthe
bikesforCan-Am,toretaintheautolubefacilityonanendurobike,soIdid.
Thewaymostofusflattenthemating
facesofacaseisbyrubbingthecaseon
anoldmirrorwhichhashadsomegrinding
pastespreadonit andlubedbyasquirtof
lightoil.Allyoudothenislaythefacetobe
flattenedonthemirror,inthegloopandswirl
thecaseroundwhileapplyinglightpressure.
It’snoisy,dirtyandboring,butworks.The
problemwithaRotaxcaseistheautolube
systempumpsoilthroughpassagesdrilledin
thecaseandit isalmostadeadcertgrinding
pastewouldfinditswayintothedrillingsand
if notcleanedoutwouldhappilydestroythe
bigendbearingwhenfittedtothebike.
Sowhat,Ihearyousay, washoutthe
drillings...It isn’tquitethateasyastheoilWhiletheclutchwasbeingdone
wedidafewotherthingstoo
asforsomereasontheoilwas
determinedtoleakpastthecase.This littlecogsitsatthebackoftheoil pump
andispreventedfromspinningbyaflatinthe
spindlehole....It wouldbereallybadfortheoilorificetohave
grindingpasteinsideit, soalightsmearofgrease
toblockitoff workedatreat....whichcorrespondstoa
flatonthepumpspindle.Thepumpwasrefittedquickly enoughandtheoil
pipescanonly gobackoneway,Istill usedmypic
forreferencethough.044 Rebuiltto ride_044.indd 45 01/08/201712:59:14