baldilocks Posted May 4, 2008 Report Share Posted May 4, 2008 (edited) Hi All When I first got my 290 it kicked back terribly when you tried to start it. Once it was run in I found it bit too powerful so retarded the timing by about 5mm as per copemechs diagram (see earlier posts). This made the power delivery much smoother and I really like the bike but it still kicks back terribly. Recently I noticed a small crack in the kickstart no doubt caused by it kicking back all the time so I got somebody to weld it. Ive tried to start it today and it kicked back as usual, bent the kickstart out of shape and re opended the crack in the kickstart so know i need a new pedal ! I'm presuming welding the pedal has weakend the alloy ? What I need to know is why my bike kicks back so much as I dont want to replace the pedal and break another one, is anyone elses 290 like this ? Can you retard the timing too far ?Its an 07 by the way cheers Edited May 4, 2008 by Baldilocks Quote Link to comment Share on other sites More sharing options...
dabomb Posted May 4, 2008 Report Share Posted May 4, 2008 (edited) I had the same problems with the same bike(including bent kickstart).Moving the stator plate completely cured the problem for me.May be you need to retard timing a bit more??,it cant do any harm,and as you know,its a 5 minute job.Asuming there is nothing wrong anywhere else,i would try doing this. PS,mmight be worth double checking that you have moved plate in right direction Edited May 4, 2008 by dabomb Quote Link to comment Share on other sites More sharing options...
copemech Posted May 5, 2008 Report Share Posted May 5, 2008 Aye, Baldi, I cannot recall what year your's is, but you can try another setting at 2-3mm further back. The further you go , the less difference it makes in actual distance on the piston. You just have to find your sweet spot! Seems "all the way" is too far and they run awkwardly. I've only broken one kickstart lever on the '05, but I believe it was from falling on it. Not sure it is practicle to repair as they may well be heat treated! Quote Link to comment Share on other sites More sharing options...
baldilocks Posted May 5, 2008 Author Report Share Posted May 5, 2008 Its an 07 copemech, trouble is I really like the performance as it is so I was hoping there was some other issue that was relevant. Maybe I need to build up my right leg so I can kick it harder in the first place. The pedal is heat treated apparently so when its been welded this has undone some of the heat treatment effect. I wouldnt recommend anyone else try welding one as I could of got a kickstart in the leg if I had been less fortunate. Quote Link to comment Share on other sites More sharing options...
ham2 Posted May 5, 2008 Report Share Posted May 5, 2008 Glen, Remind me to show you mine some-time,err,kick-start that is! As you know ,re-built the engine, test-rode it,washed it , went to kick the bike over and it was locked up solid (bent the kick-start lever)??? I had left the exhaust bung in I don't fancy heating it up to straighten it ,I'm just ignoring it,you know the scenario,let's use your style of analysis:- 1) If I heat it up to straighten it I may weaken it for the future so when I'm at that remote moorland section and I go to start her up 2) If I heat it up to straighten it I may break it..you know, that last few degrees to make it perfect...CRACK! 3) I could buy a replacement lever to carry around with me as permanent ballast ,never actually needing it until ...I sell it on...bugger! Any sign of sprogg No.2? Quote Link to comment Share on other sites More sharing options...
copemech Posted May 6, 2008 Report Share Posted May 6, 2008 (edited) Good thing is that you can buy just the top part(ali)! Still expensive, over $100 These things become somewhat awkward and dangerous if your foot slips off when wet. Best to fix it if you can. I have had my own horror stories with MX bikes, black and blue for weeks! Ouch! Edited May 6, 2008 by copemech Quote Link to comment Share on other sites More sharing options...
borus Posted May 7, 2008 Report Share Posted May 7, 2008 i have an 07 caby, i have had the timing set in positions of factory, -1mm, -2.5mm and -5mm, it has not kicked back once ever, i guess the differences in our bikes is keihin carb and hicomp head, still running stock reeds, just thought i'd let you know...oh, btw, i'm currently at -2.5mm and finding it a good mix, stock and -1mm was too much power for me. cheers Quote Link to comment Share on other sites More sharing options...
baldilocks Posted May 8, 2008 Author Report Share Posted May 8, 2008 i have an 07 caby, i have had the timing set in positions of factory, -1mm, -2.5mm and -5mm, it has not kicked back once ever, i guess the differences in our bikes is keihin carb and hicomp head, still running stock reeds, just thought i'd let you know...oh, btw, i'm currently at -2.5mm and finding it a good mix, stock and -1mm was too much power for me.cheers Hi Borus the 07 caby has a lower compression head so that it revs higher I think. My friends 07 caby is much easier to start and also doesnt kick back so maybe I could get a caby cylinder head ? Quote Link to comment Share on other sites More sharing options...
borus Posted May 9, 2008 Report Share Posted May 9, 2008 Hi Borusthe 07 caby has a lower compression head so that it revs higher I think. My friends 07 caby is much easier to start and also doesnt kick back so maybe I could get a caby cylinder head ? the sherco home page calls it a "thermodynamic cylinder head"??? be nice to know for sure what that means, i thought it was hi compression?? cheers Quote Link to comment Share on other sites More sharing options...
copemech Posted May 9, 2008 Report Share Posted May 9, 2008 I wish I knew the answer to this. I asked Ryan if he had a Caby head to examine, but no luck. Keep getting both opinions! Quote Link to comment Share on other sites More sharing options...
shercrazy Posted May 9, 2008 Report Share Posted May 9, 2008 so are we turning the plate clockwise or counter?i did mine but don't remember, but my 06 never kicked back, at least not like my 75 sherpa-t does. (ouch!) Quote Link to comment Share on other sites More sharing options...
copemech Posted May 9, 2008 Report Share Posted May 9, 2008 You turn the plate "counter" on the Sherco left side ignition to retard it! As all 2T's and 4T's are common in that the initial timing is set before TDC to some degree, they can all kick back, specially with w/limp boot! A good follow through is best, after you get them moving quickly. This also effects the motor ability to chug down low, as at some point the flywheel cannot carry through to offset the motors drive to turn the other direction, and it will stall. All I can say is that mine, once set back a bit, will at normal idle chug along in gear with no throttle, and even chug up the slight incline of my drive up. As with anything, it is a tradeoff for top performance, as your average expert may find that setting too slow on response and down on power. It seems to take about at least a 2mm change on the plate to make to make much of a "seat of the pants" change as well. And form that, you juse need to find your "sweet spot"! That is all I can tell you. Quote Link to comment Share on other sites More sharing options...
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