shercosi Posted April 9, 2008 Report Share Posted April 9, 2008 Hi everyone help needed, having chucked a bucket full of money at my bike l still find myself with a noisey engine. After the bike was stood for 12 months and not been run when I got it out got and got it to run eventually boy did it rattle so l have replaced engine mains and seals, small end bearings, water pump seals and bearings, engine back in the bike still sounded rough so on closer inspection of the piston some heavy scoreing was found so a full rebore and piston and rings have been fitted. Bike sounds good at low revs but at about 1/3 throttle l get a rattle that sounds like a loose bracket have not reved much higher but noise seems to be speeding up with the revs. Quote Link to comment Share on other sites More sharing options...
godzilla Posted April 10, 2008 Report Share Posted April 10, 2008 I had the same thing with my Sherco. I replaced everything, still a slight rattle (you have to really listern for it). I was told by a guy who had a lot to do with them that its normal. Some things wear and just never get replaced; cases etc. I have run mine for ages and it just never gets worse.. either that or its goosed! Quote Link to comment Share on other sites More sharing options...
rlracer Posted April 10, 2008 Report Share Posted April 10, 2008 Trying to answer this is like throwing a dart at a dart board with out hearing it run. Did you check the crank itself to see if it was still true ? If not, you can take the spark plug out and ground it then pull the ignition cover off and rotate the flywheel, if it is way out you can see it or Clamp a piece of steel to the bash plate and use a magnetic base with a dial indicator to check run out. Quote Link to comment Share on other sites More sharing options...
copemech Posted April 10, 2008 Report Share Posted April 10, 2008 (edited) There are "normal" noises as they are not perfectly quiet when new. Piston noise, gear noise , clutch rattle! At that throttle opening, some ignition ping is not uncommon depending upon fuel, and engine load as they are tuned sort of "on the edge". I would not freak out yet, just ride it a bit and break it in. Go to a trial and find others to compare, or other first hand knowledge from someone familar. Some of this depends upon year model as well, with changes over time in head design and such. I always ran my earlier bikes on higher octane fuel, but the latter bikes seem to run fairly well on US 93 octane, although I do have a bit of ping at times. Edited April 11, 2008 by copemech Quote Link to comment Share on other sites More sharing options...
ham2 Posted April 11, 2008 Report Share Posted April 11, 2008 I put new main bearings and seals in mine recently and now all I can hear is a rattly clutch,I was a bit paranoid about it at first but... if it runs well....ride it! Quote Link to comment Share on other sites More sharing options...
zippy Posted April 11, 2008 Report Share Posted April 11, 2008 I replaced rings, small end bearing, crank bearings, crank seals, and wrist pin. Before doing this did not hear much noise. After I hear a some what "knocking" noise. Actually seems to go away with higher revs. Or bike too loud at that point to hear the knocking. Runs great, performs well. I just figure it is cuz I was too cheap to change the piston. When I tore the engine down the rings were leaking by so badly there were scorch marks on the piston below the rings and on the cases under the crank bearings. How did that darn thing still run? Quote Link to comment Share on other sites More sharing options...
clav3 Posted April 13, 2008 Report Share Posted April 13, 2008 Sounds like pre ignition engine ping to me. My 2000 did it and my 08 does exactly the same. I ran my 2000 so rich on the pilot and needle to stop it pinging but fowled a plug every second weekend. Try raising the needle all the way up and scewing out the gas screw or a richer pilot jet to see weather it helps. If it does, try to reach a happy medium. From my experience with two bikes from 2000 to 2008 you'll never get rid of all the pinging. Quote Link to comment Share on other sites More sharing options...
Guest majestyman340 Posted April 13, 2008 Report Share Posted April 13, 2008 Hi everyone help needed, having chucked a bucket full of money at my bike l still find myself with a noisey engine. After the bike was stood for 12 months and not been run when I got it out got and got it to run eventually boy did it rattle so l have replaced engine mains and seals, small end bearings, water pump seals and bearings, engine back in the bike still sounded rough so on closer inspection of the piston some heavy scoreing was found so a full rebore and piston and rings have been fitted. Bike sounds good at low revs but at about 1/3 throttle l get a rattle that sounds like a loose bracket have not reved much higher but noise seems to be speeding up with the revs. Its impossible to rebore a nikasil cylinder, but from what you are saying it sounds as though the big end bearing is probably badly worn. In general if you are planning on keeping a bike, and its so badly worn that cylinder needs re-plating, and main bearings replacing, its false economy not to change con rod at the same time. Also on a Sherco carefully check the crankcases, as some bikes suffered from main bearing problems, which may have damaged crankcases, resulting in very loose fitting main bearings, which will mean new cases or sleeving the bearing housings. Quote Link to comment Share on other sites More sharing options...
wraggy78 Posted April 14, 2008 Report Share Posted April 14, 2008 Hi guys been reading the post so to sum it up what exactly do I need to do the mains on a 2001 290? If someone could reply to what is needed also the best place to get them in the uk. Im in the midlands not sure if there are any local ? Gonna have a go and do it myself Quote Link to comment Share on other sites More sharing options...
copemech Posted April 15, 2008 Report Share Posted April 15, 2008 Hi guys been reading the post so to sum it up what exactly do I need to do the mains on a 2001 290? If someone could reply to what is needed also the best place to get them in the uk. Im in the midlands not sure if there are any local ? Gonna have a go and do it myself Well, in lew of responding to your other post? I think at the very least you will need two new main bearings, main seals and a center case gasket, possibly a clutch side gasket depending upon how well these come apart. You need a flywheel puller, some air power and a good 3/8 drive air pistol impact. And I think it is a 24mm socket for the three large nuts, could be wrong, maybe 22mm. Seems MRS Rathmell Sports is the main sourse in the UK for stuff, don't know how to reach them, but forget about the internet as I never got them when I tried. If you have done motors before, follow Waynes instructions, but as a shortcut, mark with a chisl or scribe with a dremel disk, the three major nuts and shafts for proper reassembly and store them accordingly. Meaning the flywheel nut, the primary gear nut(other end) and the clutch hub nut, so you may reassemble to factory torque or ever so slightly beyond. There are other things that should be inspected upon disassembly, but primarily the connecting rod lower end bearing, there should be no verticle movement, and if it is loose it should go. Anything else such as waterpump shaft and seals, clutch basket, or even piston and rings can actually be done as an afterthought once the bottom end is stable. Although you would be well advised to inspect these and address things as applicable to your findings. Hope that helps! Quote Link to comment Share on other sites More sharing options...
wraggy78 Posted April 15, 2008 Report Share Posted April 15, 2008 Yes thats a great help thenk you very much I will update ..... Quote Link to comment Share on other sites More sharing options...
ham2 Posted April 16, 2008 Report Share Posted April 16, 2008 Hi guys been reading the post so to sum it up what exactly do I need to do the mains on a 2001 290? If someone could reply to what is needed also the best place to get them in the uk. Im in the midlands not sure if there are any local ? Gonna have a go and do it myself Read these:- Idiots guide (I can prove it!) 1 2 3 It's running so well now that I feel quite smug when I ride it Quote Link to comment Share on other sites More sharing options...
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