serafumi Posted August 29, 2010 Report Share Posted August 29, 2010 hi all , i recently brought a sherco 290 04 model , bike is very clean and looks like its had hardly any use!! however ever since i have had it , its got a really annoying whine , sounds like its drive related .. last week i stripped the engine completely and replaced , mains , all gearbox bearings, rings , waterpump bearing and a few other things!! im a motorcycle mechanic by trade so i should know what im looking at lol!! all the gears look ok , selectors are good . however once all back together and running it still whines??? you can change the noise with the clutch!!! i have been told by a few people at my local trials place that all early shercos whine!!! surely this cant be true!! can anyone shed some light!! cheers tony Quote Link to comment Share on other sites More sharing options...
copemech Posted August 30, 2010 Report Share Posted August 30, 2010 hi all , i recently brought a sherco 290 04 model , bike is very clean and looks like its had hardly any use!! however ever since i have had it , its got a really annoying whine , sounds like its drive related .. last week i stripped the engine completely and replaced , mains , all gearbox bearings, rings , waterpump bearing and a few other things!! im a motorcycle mechanic by trade so i should know what im looking at lol!! all the gears look ok , selectors are good . however once all back together and running it still whines??? you can change the noise with the clutch!!! i have been told by a few people at my local trials place that all early shercos whine!!! surely this cant be true!! can anyone shed some light!!cheers tony I suppose first question is are you sure it is abnormally loud? There is some normal whine from things here. If it sounds loke a Scorpa Yam or worse, there is a problem. I would start with a close reinspection of the bearings in and behind the clutch including the main shaft. Quote Link to comment Share on other sites More sharing options...
serafumi Posted August 30, 2010 Author Report Share Posted August 30, 2010 hi cope thanks for reply , i hvae never heard a yam so i cant compare!! however all the other shercos i have heard do not sound like this , if you hold the front brake on and release the clutch , just as the clutch starts to send drive to back wheel the noise goes then comes back once riding , if you rev it in neutral it does it , its just very annoying , i just feel it must be clutch related as you can vary the noise!! the only bearings i didnt replace were clutch release and the needle roller in the clutch centre! could it be these? thanks again tony Quote Link to comment Share on other sites More sharing options...
1oldbanjo Posted August 30, 2010 Report Share Posted August 30, 2010 Tony: The Sherco uses straight cut primary gears......and these do whine. The pitch changes as the load is applied. Most road going bikes and enduro's use helical primary gears which make much less noise - but are not as efficient in transferring power as they make a lot of side thrust. I suspect that what you are hearing is the whine of the primary gears.....which may be normal. Since your bike looks unused, maybe there just isn't enough use to break in the gears yet? Maybe the gear set you have does not fit up very well and is noisier than most? Quote Link to comment Share on other sites More sharing options...
ormplus Posted August 30, 2010 Report Share Posted August 30, 2010 check your clutch basket the rivets on them and it moves back and forward. fitted s/hand one last week and it cured the problem. Quote Link to comment Share on other sites More sharing options...
serafumi Posted August 30, 2010 Author Report Share Posted August 30, 2010 Tony:The Sherco uses straight cut primary gears......and these do whine. The pitch changes as the load is applied. Most road going bikes and enduro's use helical primary gears which make much less noise - but are not as efficient in transferring power as they make a lot of side thrust. I suspect that what you are hearing is the whine of the primary gears.....which may be normal. Since your bike looks unused, maybe there just isn't enough use to break in the gears yet? Maybe the gear set you have does not fit up very well and is noisier than most? this is a very interesting point, i kinda thought that may be the case. i have just never heard a sherco as loud as mine?? its very annoying Quote Link to comment Share on other sites More sharing options...
serafumi Posted August 30, 2010 Author Report Share Posted August 30, 2010 check your clutch basket the rivets on them and it moves back and forward. fitted s/hand one last week and it cured the problem. hi , the basket deffinatly moves back and forth , theres a few marks on the basket fingers, maybe i will buy a basket and new rivets?? Quote Link to comment Share on other sites More sharing options...
houseape1000 Posted August 30, 2010 Report Share Posted August 30, 2010 (edited) Try these - Click me ! Sorry.....I couldn't resist ! Edited August 30, 2010 by houseape1000 Quote Link to comment Share on other sites More sharing options...
copemech Posted August 31, 2010 Report Share Posted August 31, 2010 If it does it revving in neutral with clutch out, the main shaft and bearings are still spinning up, yet there is not much load on the primary gears. If put into gear(clutch in) the noise stops, the main shaft is isolated by the clutch and not spinning or under load. If noise continues, it is in the primary gears or clutch hub bearing. The main shaft bearing should be tight, with little to no movement! Quote Link to comment Share on other sites More sharing options...
serafumi Posted August 31, 2010 Author Report Share Posted August 31, 2010 If it does it revving in neutral with clutch out, the main shaft and bearings are still spinning up, yet there is not much load on the primary gears.If put into gear(clutch in) the noise stops, the main shaft is isolated by the clutch and not spinning or under load. If noise continues, it is in the primary gears or clutch hub bearing. The main shaft bearing should be tight, with little to no movement! hi cope , the main shaft and output shaft bearings are all new ,, u can hear the noise in neutral once revved and just as they come down to idle it whines , u can also change the noise with the clutch in , in neutral cheers tony Quote Link to comment Share on other sites More sharing options...
copemech Posted September 1, 2010 Report Share Posted September 1, 2010 hi cope , the main shaft and output shaft bearings are all new ,, u can hear the noise in neutral once revved and just as they come down to idle it whines , u can also change the noise with the clutch in , in neutral cheers tony In neutral once revved, you are still spinning up the main shaft. Placing in gear and clutch in isolates that section, main shaft stops turning. Now apply a load feeding in the clutch, yet brake held, so gears on both shafts cannot move. The only things spinning here are the clutch and primary gears. Main and output shaft are locked into the gear and not moving. Spinning components are still primary drive gears and main clutch bearing. If noise appears under load from clutch, these are suspect. If mainshaft must spin for noise to occur, the latter. Hope that makes sense! Quote Link to comment Share on other sites More sharing options...
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