dantyper Posted February 26, 2016 Report Share Posted February 26, 2016 Hi guys, I recently bought a Sherco 250 2010 bike which appeared to be running pretty sweet on my first outing until I did a 3rd gear hill climb (not screwing the engine). Once i reached the top and stopped, the bike died even though I had the clutch in. It then took a while to get started again and when it did finally start I had to wind the tick over up a bit to prevent it from stalling. Since then I purchased a new air filter and I took the carb out of the bike and thoroughly cleaned it all out with an airline. Some of the jets were pretty blocked up, so I thought that could have been the issue. I put it back together and it fired up straight away. I adjusted the idle and it now sounds spot on and starts 1st or 2nd kick and sounds perfect on tick over. The problem I am now facing is that if the bike is held at mid revs in neutral it produces a really loud cracking and popping sound out the exhaust which firstly I am sure it never used to do and secondly it just doesn't sound right. It also does this thing, where if you rev it up in neutral and then let the revs return back to idle, it doesn't do the 'ring ding ding' noise as it drops down the revs. It just makes a constant noise like a 4 stroke engine would. My friends GasGas 250 will make the 'ring ding ding' noise once returning down to idle. Once my Sherco returns to it's idle, it will do the 'ring ding ding' sound again and it sounds ok. But it certainly doesn't sound crisp during it's down revving. I have blasted the inlet manifold with easy start whilst the bike is running to check for air leaks. I sprayed it on nearly every gasket and it had no effect on the idling of the bike, which suggests it isn't pulling in any air from there. Any help is appreciated guys! Cheers, Dan. Quote Link to comment Share on other sites More sharing options...
worldtrialchamp Posted February 26, 2016 Report Share Posted February 26, 2016 start simple 1. Spark plug 2. Fuel flow 3. Compression 4. Exhaust and combustion chamber cleanliness or seek a mechanic Quote Link to comment Share on other sites More sharing options...
sprinter Posted February 26, 2016 Report Share Posted February 26, 2016 Sounds like sheared fly wheel key to me Quote Link to comment Share on other sites More sharing options...
jfc Posted February 26, 2016 Report Share Posted February 26, 2016 Long shot but may be worth unplugging your multi pinned CDI and check to see if any moisture on the connection pins has caused any corrosion to form on the pins, this can cause the symptoms you describe and can be misstaken for fuelling / Carb problems. If you find any corosion on the pins just clean the pins with WD40 and gently rub the pins with a terminal screw driver to remove the corrosion. Quote Link to comment Share on other sites More sharing options...
ham2 Posted February 26, 2016 Report Share Posted February 26, 2016 Stator coil failing? Quote Link to comment Share on other sites More sharing options...
copemech Posted February 27, 2016 Report Share Posted February 27, 2016 Lets have a video so we can hear this. Your description is a bit vague to me. Quote Link to comment Share on other sites More sharing options...
pauls320 Posted February 27, 2016 Report Share Posted February 27, 2016 I would first try a new spark plug....has the fuel hose system been updated ?? Quote Link to comment Share on other sites More sharing options...
jfc Posted March 2, 2016 Report Share Posted March 2, 2016 Bump, any news? Quote Link to comment Share on other sites More sharing options...
dantyper Posted March 4, 2016 Author Report Share Posted March 4, 2016 Hi guys, sorry for the late response. The bike is still not running perfectly. I went out on it last weekend for a few hours and it works, but i dont have faith in it because its not running 100%. I think what I need to do is take it to a trials specialist and let them hear the thing running and take it for a spin. Like copemech said, a video is pretty crucial to diagnose this issue, i will try get one uploaded. It's hard for me to explain what it is doing. But it certainly isn't running as it should be. i ordered a new spark plug, for the sake of a few quid. Cheers. Quote Link to comment Share on other sites More sharing options...
dantyper Posted March 16, 2016 Author Report Share Posted March 16, 2016 Hi guys, If a stator was to fail or be temperamental, what would the effect be on the bike? ie what does the stator actually do? Last weekend i was out on the bike. Started 1st kick, rode sweet for 10 mins, then all of a sudden it started making a real lumpy whiring sound on tickover. It wanted to cut out unless i kept the revs up. i wound the tickover up slightly to stop it actually stalling. Then 5 minutes later it was ticking over okay again. When i say okay, it certainly wasn't lumpy or making a misfire sound, but i didn't have full confidence in it, especially after what had happened 5 minutes earlier. I fit a new spark plug but that doesnt seem to have cured anything, but it was worth a try. I will get this to a specialist, its just finding the time during their opening hours for me to do it. In the meantime your help is much appreciated. Quote Link to comment Share on other sites More sharing options...
tony27 Posted March 17, 2016 Report Share Posted March 17, 2016 A dodgy stator normally stops sparking when hot, definitely not what you just described. Sounds almost like you have some water somewhere that partially blocked your pilot jet for a short time Quote Link to comment Share on other sites More sharing options...
digger144 Posted March 17, 2016 Report Share Posted March 17, 2016 check the breather pipes from carb, a mate had similar issues & had to shorten breather pipe that had blocked with mud. Quote Link to comment Share on other sites More sharing options...
dantyper Posted March 17, 2016 Author Report Share Posted March 17, 2016 Thanks Tony27. I know what you are saying regarding the water, but it did the exact same thing once before. It's almost like it goes dodgy once it is fully up to temperature after 10 mins or so. digger144. Okay, cheers i will have a look. Just to confirm, the breather comes off the carb from either side and the hose creates a 'U' shape? I do know that mine has split in half and so essentially there is a piece of hose hanging down from either side of the carb, the 'U' is broken. Could this cause the bike issues? Cheers. Quote Link to comment Share on other sites More sharing options...
jkendall Posted March 17, 2016 Report Share Posted March 17, 2016 Few suggestions for you... Firstly if it is struggling to tick over it could be one of a few things: 1) Lack of fuel - Check breather pipe on petrol cap, check flow from tank to carb, ensure the filter on the fuel inlet of the carb isn't blocked. Strip carb, check all O-rings etc (ensure no air is getting in)...& make sure jets are clean. 2) Check rubbers between carb and engine to ensure no cracks & also shine a light in on reed block to ensure petals are fully intact and closed. 3) Check crank seal on flywheel side (may have dried out and be allowing air in causing poor tick over. 4) Ensure flow of exhaust gas right through to exit is clear...be sure none of the exhaust system has collapsed inside! This can prevent gases escaping, cause a bike to sound strange and ultimately prevent it ticking over properly. It would also cause the holding over revs, and stop it "ring ding dinging" as you put it Hope those ideas help, Thanks, James Quote Link to comment Share on other sites More sharing options...
jkendall Posted March 17, 2016 Report Share Posted March 17, 2016 Just come across this too: http://www.splatshop.co.uk/2010-2011-sherco-preparation 1 Quote Link to comment Share on other sites More sharing options...
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