seventies2stroke Posted December 18, 2010 Share Posted December 18, 2010 Hi to all,I need some advice regarding my 79 xs 250 I have been trying to trace a idling problem once the bike is warm,done the basics,fuel ok,points new and gapped properly.I thought I'd check the ignition timing,so I pulled off the cover to get alook at the timing marks,jeeze I thought that I'd undone the sump plug by mistake!oil every where inside the alternator,it's a wonder that it was running,is there an oil seal behind the alternator rotor or do I have a big problem?Is this a common fault with the xs 250? Any help would be appreciated........thank you Link to comment Share on other sites More sharing options...
Moderator drewpy Posted December 18, 2010 Moderator Share Posted December 18, 2010 Hi to all,I need some advice regarding my 79 xs 250 I have been trying to trace a idling problem once the bike is warm,done the basics,fuel ok,points new and gapped properly.I thought I'd check the ignition timing,so I pulled off the cover to get alook at the timing marks,jeeze I thought that I'd undone the sump plug by mistake!oil every where inside the alternator,it's a wonder that it was running,is there an oil seal behind the alternator rotor or do I have a big problem?Is this a common fault with the xs 250? Any help would be appreciated........thank you main stand or side stand? Link to comment Share on other sites More sharing options...
seventies2stroke Posted December 18, 2010 Author Share Posted December 18, 2010 main stand or side stand? Sorry,I what difference does the stand make? Link to comment Share on other sites More sharing options...
2 Wheels Posted December 19, 2010 Share Posted December 19, 2010 Sorry,I what difference does the stand make? He's takin da piss,,,,,cause ya didnt introduce ya self ! He's also da man in da know about the XS's :) Link to comment Share on other sites More sharing options...
seventies2stroke Posted December 19, 2010 Author Share Posted December 19, 2010 Hey sorry,start again? Old bloke not very good with four strokes,was brought up on screaming two strokes in the very early seventies(wish I still had the bikes)just bought a reasonable xs 250,as I'm back riding after a 35year lapse!I hope you can help as I'm a bit lost...worked out that he's takin the pi** but did'nt know why.....thanks for your help 2Wheels Link to comment Share on other sites More sharing options...
2 Wheels Posted December 19, 2010 Share Posted December 19, 2010 Hey sorry,start again? Old bloke not very good with four strokes,was brought up on screaming two strokes in the very early seventies(wish I still had the bikes)just bought a reasonable xs 250,as I'm back riding after a 35year lapse!I hope you can help as I'm a bit lost...worked out that he's takin the pi** but did'nt know why.....thanks for your help 2Wheels Well, i dont think ya have a huge problem,,,,,,i remember something that sound kinda like this in another thread,,,,,,dont quote me but i think there is something above but inside the cover of the alternator that is prone to a little oil leak on the XS,,,,,,,,,,,,,,,I may be very wrong though,,,,,,,,my memory is not what it used to be.. Anyway,, sit tight for a while and someone might be able to sort ya out. Good luck with her/it !!! Link to comment Share on other sites More sharing options...
JimR Posted December 19, 2010 Share Posted December 19, 2010 Hi to all,I need some advice regarding my 79 xs 250 I have been trying to trace a idling problem once the bike is warm,done the basics,fuel ok,points new and gapped properly.I thought I'd check the ignition timing,so I pulled off the cover to get alook at the timing marks,jeeze I thought that I'd undone the sump plug by mistake!oil every where inside the alternator,it's a wonder that it was running,is there an oil seal behind the alternator rotor or do I have a big problem?Is this a common fault with the xs 250? Any help would be appreciated........thank you Hi There, The XS250/400 alternators run in oil, I would guess the oil is running out of the small hole at the bottom of the case ? if so there are a few causes :- The engine is over full of oil the alternator cover was removed with the bike on the side stand ( the oil will lie to the l/h side of the engine). Fuel has entered the crankcase (worn bores etc) and has 'topped' up the oil level. Was the oil rather runny ? If so this would indicate fuel in the oil Link to comment Share on other sites More sharing options...
seventies2stroke Posted December 19, 2010 Author Share Posted December 19, 2010 Hi There, The XS250/400 alternators run in oil, I would guess the oil is running out of the small hole at the bottom of the case ? if so there are a few causes :- The engine is over full of oil the alternator cover was removed with the bike on the side stand ( the oil will lie to the l/h side of the engine). Fuel has entered the crankcase (worn bores etc) and has 'topped' up the oil level. Was the oil rather runny ? If so this would indicate fuel in the oil Link to comment Share on other sites More sharing options...
seventies2stroke Posted December 19, 2010 Author Share Posted December 19, 2010 Hi thanks for your reply.the bike was on its side stand at first,then transferred to the main stand,I did'nt check the oil before I took off the case,but I will now,I don't think that the bores would be to bad as the bike has only done 21000 miles,the oil was very dirty,but not what you would call thin.....I'll have a look and get back online with what I find,thanks. Link to comment Share on other sites More sharing options...
seventies2stroke Posted December 19, 2010 Author Share Posted December 19, 2010 Hi thanks for your reply.the bike was on its side stand at first,then transferred to the main stand,I did'nt check the oil before I took off the case,but I will now,I don't think that the bores would be to bad as the bike has only done 21000 miles,the oil was very dirty,but not what you would call thin.....I'll have a look and get back online with what I find,thanks. Update oil level ok.I'm guessing that the oil that was present was there because the bike had spent along time on it's side stand?I don't believe that the bike has been serviced for a long time,just been and checked the air filters(looking for the original problem which was poor idle when hot)the filters are really bad and the left hand one is full of fuel any ideas guys?I'm gonna give it an oill change and all new filters any way... Link to comment Share on other sites More sharing options...
JimR Posted December 19, 2010 Share Posted December 19, 2010 Update oil level ok.I'm guessing that the oil that was present was there because the bike had spent along time on it's side stand?I don't believe that the bike has been serviced for a long time,just been and checked the air filters(looking for the original problem which was poor idle when hot)the filters are really bad and the left hand one is full of fuel any ideas guys?I'm gonna give it an oill change and all new filters any way... add stripping the carbs down, setting valve clearences, dwell angles, ignition timing and compression testing to your to do list . Link to comment Share on other sites More sharing options...
seventies2stroke Posted December 19, 2010 Author Share Posted December 19, 2010 That should keep me busy,thanks for your help guys....... Link to comment Share on other sites More sharing options...
Moderator drewpy Posted December 19, 2010 Moderator Share Posted December 19, 2010 Sorry,I what difference does the stand make? on the side stand oil pisses out, on the main stand it stays in! Link to comment Share on other sites More sharing options...
seventies2stroke Posted December 19, 2010 Author Share Posted December 19, 2010 on the side stand oil pisses out, on the main stand it stays in! Yep now I know,like I said before I'm new to four strokes,but I'm catching up fast,thanks for your help,do you have any other ideas regarding the poor idle when hot?Jimr has made afew sugguestions which I will do.The bike does struggle a little to start,then runs fine,even idles ok,then after about 10 mins the idle fades...and it stops Link to comment Share on other sites More sharing options...
blackhat250 Posted December 19, 2010 Share Posted December 19, 2010 .The bike does struggle a little Most four strokes do ,, Welcome 70sstroker " keep asking , eventualy drewpy will answer senciblly , Hes like scrooge at this time of year, Bah ,,,, By the way you shouda stuck to 2 smokes " all oil will be burnt Link to comment Share on other sites More sharing options...
seventies2stroke Posted December 19, 2010 Author Share Posted December 19, 2010 Hey blackhat250 thank you for your reply,I cut my teeth on yams in 1971,we really used to pi** the guys off of their BSA's and Triumphs,even got nicked by a copper on a 650 triumph,he struggled to catch me...when he finally stopped me I could'nt convince him that I was only on a 250...should have seen his face...think I should start looking for 71/72 250 again or maybe a 350 wahoo! Link to comment Share on other sites More sharing options...
Moderator drewpy Posted December 19, 2010 Moderator Share Posted December 19, 2010 Yep now I know,like I said before I'm new to four strokes,but I'm catching up fast,thanks for your help,do you have any other ideas regarding the poor idle when hot?Jimr has made afew sugguestions which I will do.The bike does struggle a little to start,then runs fine,even idles ok,then after about 10 mins the idle fades...and it stops you need to check all the basics, compression, timing (valve and ignition). you may have to play around with the pilot adjustment on the carb yellow in the diagram you'll have to excuse me, i got man flu!! Link to comment Share on other sites More sharing options...
seventies2stroke Posted December 19, 2010 Author Share Posted December 19, 2010 Hey drewpy thanks for the pic,I will get back to you,hopefully to say it's sorted........... Link to comment Share on other sites More sharing options...
HoughMade Posted December 21, 2010 Share Posted December 21, 2010 In the shop manual I have, it says to drain the oil before removing the alternator cover....because oil is supposed to be behind the cover. Less comes out when it is on the center stand, but nothing is wrong, nothing is amiss, nothing is leaking if there is oil behind the alternator cover. Link to comment Share on other sites More sharing options...
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