skik Posted May 6, 2011 Share Posted May 6, 2011 hi folks.my yamaha sr125 is smokin a bit from the exhaust[white smoke]could it be anything else other than rings.anything i should check before i take the head off? Link to comment Share on other sites More sharing options...
Moderator drewpy Posted May 7, 2011 Moderator Share Posted May 7, 2011 hi folks.my yamaha sr125 is smokin a bit from the exhaust[white smoke]could it be anything else other than rings.anything i should check before i take the head off? white is usually over rich mix, could be float in carb/ needle issue. need to get it done asap as it'll bore wash the oil in the cyl and then you will need a rebore Link to comment Share on other sites More sharing options...
Moderator Cynic Posted May 7, 2011 Moderator Share Posted May 7, 2011 white is usually over rich mix, could be float in carb/ needle issue. need to get it done asap as it'll bore wash the oil in the cyl and then you will need a rebore Isn't that normally black smoke Andy? Skik it depends on WHEN it smokes, under power it may be the rings or the mixture, on the overun (when slowing down with the throttle shut) it may well be the valve seals. If it smokes at first start up that is also valve seals generally. Most of my 4 strokes have been cheap junk with one of the above issues with one exception. Fortunately i learned my lesson and stick with 2 strokes now Link to comment Share on other sites More sharing options...
skik Posted May 7, 2011 Author Share Posted May 7, 2011 Isn't that normally black smoke Andy? Skik it depends on WHEN it smokes, under power it may be the rings or the mixture, on the overun (when slowing down with the throttle shut) it may well be the valve seals. If it smokes at first start up that is also valve seals generally. Most of my 4 strokes have been cheap junk with one of the above issues with one exception. Fortunately i learned my lesson and stick with 2 strokes now how do i check valve seals and what am i looking for Link to comment Share on other sites More sharing options...
blackhat250 Posted May 8, 2011 Share Posted May 8, 2011 Hi skik. the valve stem seals, symptom , is when engine sits overnight , the oil thats been pumped up to topend,[ head] , runs down valvestems . if seals are worn or hardend, a little oil seeps past , & into combustion chamber, when starting, will burn off, whte/blue smoke. nowt to worry about , check oil levels regulary . Link to comment Share on other sites More sharing options...
Moderator drewpy Posted May 8, 2011 Moderator Share Posted May 8, 2011 mine was white when i had float level issues. I've also had worn valve stem seals and its the smell gives it away! Link to comment Share on other sites More sharing options...
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