argentum40 Posted July 17, 2012 Share Posted July 17, 2012 Lads i wonder if any of you smart lot can point me in the right direction here.. Basically i have a 2 stroke twin and when engine is cold and choke is on it idles and pulls fine from a standstill.. Once warmed up it bogs down relaly badly and wont idle at all...I have checked all the usual stuff like plugs and air filter etc and also checked the inlet rubber in case its split but all seems fine..Could it be an air leak, a weak spark on one of the cylinders as it sounds like it could be dropping to one cylinder before it stalls or something else? Quote Link to comment Share on other sites More sharing options...
gravelrashedaprilia Posted July 17, 2012 Share Posted July 17, 2012 2 strokes, despite being simple, are very finicky. Could be lots of things, even the crank oil seals which have failed which causes the symptons you described. Quote Link to comment Share on other sites More sharing options...
argentum40 Posted July 17, 2012 Author Share Posted July 17, 2012 yeah someone else mentioned crank oil seals... it can be a twat to start sometimes yet other times it fires straight away... once revs are up it pulls like a train Quote Link to comment Share on other sites More sharing options...
Weebl Posted July 17, 2012 Share Posted July 17, 2012 Is the choke definitely coming all the way off? The symptoms would fit if the choke was sticking on. Quote Link to comment Share on other sites More sharing options...
argentum40 Posted July 17, 2012 Author Share Posted July 17, 2012 yeah the choke is a plunger type which you manually push and pull... its working correctly mate Quote Link to comment Share on other sites More sharing options...
eastanglianbiker Posted July 17, 2012 Share Posted July 17, 2012 one way to check the left hand crank seal is check behind the outer casing as its meant to be dry and clean in there no oil residue or oily film as its that area that the points or electronic ign units would be Quote Link to comment Share on other sites More sharing options...
argentum40 Posted July 17, 2012 Author Share Posted July 17, 2012 EAB i had that casin off last week and its clean as a whistle on there... no signs of oil at all. Quote Link to comment Share on other sites More sharing options...
eastanglianbiker Posted July 17, 2012 Share Posted July 17, 2012 then crankseal on that side of the engine should be ok it could be the other side or have you done compression check on it to make sure it hasnt lost any?and have you checked for air leaks by spraying some easy start/wd40 or anything like it to see if revs increase? Quote Link to comment Share on other sites More sharing options...
Joeman Posted July 17, 2012 Share Posted July 17, 2012 What's it do if you put it on choke when its warm?? Does that stop the stall??Sounds like you need to get the carb off and give all the little jets a good blow out.What engine is it anyway?? Does it have reed valves?? If they wear out and not close properly you get similar problems.. Quote Link to comment Share on other sites More sharing options...
argentum40 Posted July 17, 2012 Author Share Posted July 17, 2012 EAB it could be leaking at the clutch side but i cant spray that side with engine running.. i have tried around the head, base gasket, inlet rubber etc and made no difference to revs at all..the carb has brand new jets in it and it has been cleaned so many times its beyond a joke... it doesnt have reeds at all it just has the carb then inlet rubber onto the head.. choke on when its warm kills the engine straight away.. Quote Link to comment Share on other sites More sharing options...
eastanglianbiker Posted July 17, 2012 Share Posted July 17, 2012 i assume you have checked mixtures and that both carbs are set the same then next its compression check to see if one cylinder is a lot lower than the other Quote Link to comment Share on other sites More sharing options...
argentum40 Posted July 17, 2012 Author Share Posted July 17, 2012 i assume you have checked mixtures and that both carbs are set the same then next its compression check to see if one cylinder is a lot lower than the other its a single carb mate and as the other cylinder is fine i wouldn tthink it would be a carb issue... could points or condensor cause it as it has a set for each cylinder Quote Link to comment Share on other sites More sharing options...
eastanglianbiker Posted July 18, 2012 Share Posted July 18, 2012 yes it could be a set of points burning out normally the condensor will either work or it wont they dont often become intermitantly faulty other thing to do is give it a blast then while still hot carefully remove the plugs to do colour check on them see if they show up as being different colours from each other Quote Link to comment Share on other sites More sharing options...
argentum40 Posted July 18, 2012 Author Share Posted July 18, 2012 yes it could be a set of points burning out normally the condensor will either work or it wont they dont often become intermitantly faulty other thing to do is give it a blast then while still hot carefully remove the plugs to do colour check on them see if they show up as being different colours from each other i did that the other day EAB and they are both the same colour.. a kinda of dark caramel colour... Quote Link to comment Share on other sites More sharing options...
Joeman Posted July 18, 2012 Share Posted July 18, 2012 Doesnt sound like an electrical problem to me - if its fine when its cold and on choke, then starts playing up when its warm and off choke...Just an idea - its getting enough oil right? i mean its not partially seizing up when it gets warm? Quote Link to comment Share on other sites More sharing options...
argentum40 Posted July 18, 2012 Author Share Posted July 18, 2012 no its not nippin when warm mate,,.,. once the revs are up it goes like the clappers... as the revs drop it sounds like its dropping to one cylinder but that of course is just a guess... it may just be very weak on the poor cylinder Quote Link to comment Share on other sites More sharing options...
eastanglianbiker Posted July 18, 2012 Share Posted July 18, 2012 compression test it and if that is showing up as ok on both cylinders then its time to start looking again Quote Link to comment Share on other sites More sharing options...
argentum40 Posted July 18, 2012 Author Share Posted July 18, 2012 right this is what i have checked today.... swapped coils over and plugs which made no difference.... Took head off what i thought was the poor cylinder and checked gasket, gave it a decoke while i was i there... no difference... carb and inlet rubber off again and after a thorough check of both and a clean of the carb again... no difference... finally i checked the compression on what i think is the bad cylinder and it has tons of compression for a 2 stroke... so back to square one again Quote Link to comment Share on other sites More sharing options...
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