lingo75 Posted April 26, 2010 Report Share Posted April 26, 2010 (edited) Hello chaps, my 99 mont has developed a worrying noise from the engine, only way i can describe it is 'a bit rattly' or 'a bit like an old tractor!' no difference in performance just a lack of the nice purring i used to have. Should i take the crank case covers off and see if the flywheel is loose - any other ideas? is it all gonna go pear shaped if i leave it?? (i dont want to do that i want it sounding nice again!) many thanks Dan Edited April 26, 2010 by Lingo75 Quote Link to comment Share on other sites More sharing options...
tt5th Posted April 26, 2010 Report Share Posted April 26, 2010 Did it start suddenly or has it just got gradually worse? Does it happen in a particular part of the rev range? Leaving it will be a bad thing in the long run. Checking the flywheel is easy enough, it could be the top end which is easy enough to take off and have a look. Worst case it could be the bottom end, best case it could be a leak in your exhaust somewhere or something else equally simple. Sometimes you can find the spot where its knocking by putting the metal end of a screwdriver against various parts of the engine and putting the rubber end on your ear. Works like a cowboy stethoscope! Quote Link to comment Share on other sites More sharing options...
lingo75 Posted April 26, 2010 Author Report Share Posted April 26, 2010 Thanks for the reply! Well it started this weekend, never noticed it before. Funny you should say about the exhaust as i had had the front pipe off to spray it this weekend and i think it was after i replaced it that i noticed the noise, could that be it?? Quote Link to comment Share on other sites More sharing options...
b40rt Posted April 26, 2010 Report Share Posted April 26, 2010 Thanks for the reply!Well it started this weekend, never noticed it before. Funny you should say about the exhaust as i had had the front pipe off to spray it this weekend and i think it was after i replaced it that i noticed the noise, could that be it?? Always start with the last thing you did to the bike, when trying to isolate a problem ! Quote Link to comment Share on other sites More sharing options...
lingo75 Posted April 26, 2010 Author Report Share Posted April 26, 2010 ha. Yeah i get that, but i due to my lack of the knowse i don't know why refitting the exhaust could cause a knocking/rattle. Is it because it is not sealed/air tight?? and what does that do to make the noise?? sorry for all the questions. But i guess that's one of the reasons for a forum??!! Quote Link to comment Share on other sites More sharing options...
b40rt Posted April 26, 2010 Report Share Posted April 26, 2010 If its touching the frame / engine at any point (where it should'nt) you could well get a rattle. Quote Link to comment Share on other sites More sharing options...
lingo75 Posted April 26, 2010 Author Report Share Posted April 26, 2010 Aha, gotcha muchos gracias! I dont think it is though (will check) the noise deffo sounds like it is coming 'from within' which is a worry!!! in answer to initial questions Did it start suddenly or has it just got gradually worse? Well i noticed it on Saturday and have never heard it before so i'd say gradually. It hasn't got worse (rode a trial with it like it on Sunday) Does it happen in a particular part of the rev range? Nope just always there in the background, no change in performance Thanks in advance to anyone who replies. I really really appreciate it. Ta Dan Quote Link to comment Share on other sites More sharing options...
tt5th Posted April 26, 2010 Report Share Posted April 26, 2010 Definately double check the exhaust if that's something you've had off. Make sure it's all sealed nicely and the gasket didn't fall out/off when you removed it. I only mentioned it as on one of my other bikes I could have sworn it was tapping and it just turned out to be a loose exhaust manifold bolt so it wasn't sealing properly. Rattling in the top end usually changes with revs. Normally worse when the engine is settling back down after a high rev. Check all the simple things first though, 315's are usually bombproof. Quote Link to comment Share on other sites More sharing options...
lingo75 Posted April 27, 2010 Author Report Share Posted April 27, 2010 Thanks all. Should there be a 'proper' gasket where the front pipe goes in the engine. As i seem to remember it just looked a bit liek clear silicone or sort of off colour rubber. I reckon i need to put a new kind of seal on there - what should i use?? Quote Link to comment Share on other sites More sharing options...
lingo75 Posted April 27, 2010 Author Report Share Posted April 27, 2010 Hmmmm may have answered my own question... I reckon i should put a new one on http://www.apexmotosports.com/montesa%20pa...20book/f-12.htm http://www.jimsandiford.co.uk/exhaust-seal...r1-680-68-p.asp what say you experts?? Quote Link to comment Share on other sites More sharing options...
tt5th Posted April 27, 2010 Report Share Posted April 27, 2010 I don't know what the experts say but i say yes, that's what you need. Sounds like you've disturbed someones bodged repair, not certain but worth a try for fiver. Quote Link to comment Share on other sites More sharing options...
lingo75 Posted April 27, 2010 Author Report Share Posted April 27, 2010 or even Quote Link to comment Share on other sites More sharing options...
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