skik Posted September 21, 2010 Share Posted September 21, 2010 hi.i still cant seem to get my yamaha sr125 running 100%.it idles and runs ok its just if you give it quick throttle from idle it will die[bit of a bummer taking off at lights]i have checked and cleaned all i can think of.this is,carb and jets many times[carb cleaner,air gun].have fitted new idle/slow jet,air filter seated well no leaks,inlets to carb no leaks[sprayed around with carb cleaner no different]float height and fuel height ok. mixture screw to the best i can get it[one and a half turns out]peacock and fuel lines clear.valve clearance ok.new plug which looks ok[nice and brown]moved clip on needle up one,then down one notch.tried fresh fuel.checked coil and lead for spark leak[at night]taped up lead anyway.fixed small blow out in exhaust.it will just happen from idle,if the revs are up slightly it will take the quick throttle ok.i could live with it[i guess]but its the first thing people do when they get on it[quick twist and it dies]HELP! Link to comment Share on other sites More sharing options...
2 Wheels Posted September 21, 2010 Share Posted September 21, 2010 Correct pulg heat range ? Is the slider in the carb nice and free. Link to comment Share on other sites More sharing options...
skik Posted September 21, 2010 Author Share Posted September 21, 2010 Correct pulg heat range ? Is the slider in the carb nice and free. slider goes up and down freely.the plug i have is the one suggested in the manual ngk d8ea Link to comment Share on other sites More sharing options...
Moderator Airhead Posted September 21, 2010 Moderator Share Posted September 21, 2010 Its not a diaphragm carb is it? Link to comment Share on other sites More sharing options...
skik Posted September 21, 2010 Author Share Posted September 21, 2010 Its not a diaphragm carb is it? no slide type Link to comment Share on other sites More sharing options...
Moderator Airhead Posted September 21, 2010 Moderator Share Posted September 21, 2010 Have you got a Haynes manual? What about float height, could it be too much, making for a lean mix? What happens if you put choke on and then snap open the throttle? Link to comment Share on other sites More sharing options...
Moderator Airhead Posted September 21, 2010 Moderator Share Posted September 21, 2010 Has the needle detached from the slide? Link to comment Share on other sites More sharing options...
skik Posted September 21, 2010 Author Share Posted September 21, 2010 Have you got a Haynes manual? What about float height, could it be too much, making for a lean mix? What happens if you put choke on and then snap open the throttle? everything set to haynes manual.the choke works with a knob on the side of the carb.i think its meant to stay out when you pull it but it springs back.you need to hold it out to start from cold.once it fires up you let it go and it will tick over sweet.if you pull it full on when warm it will die but half on it will rev up and you can snap the throttle ok.sorry about all the shit im just trying to explain Link to comment Share on other sites More sharing options...
Moderator Airhead Posted September 21, 2010 Moderator Share Posted September 21, 2010 .........if you pull it full on when warm it will die but half on it will rev up and you can snap the throttle ok. so that cofirms it then , it's a carb issue and its fuel starved when you snap open the throttle quickly. However much you think you have fettled this carb, something still isnt right, still a bit lean somewhere, the things I said before could be the cause, or partially blocked jets...did you look at the holes in the jets through a magnifying glass, are they perfectly clean? Link to comment Share on other sites More sharing options...
skik Posted September 21, 2010 Author Share Posted September 21, 2010 so that cofirms it then , it's a carb issue and its fuel starved when you snap open the throttle quickly. However much you think you have fettled this carb, something still isnt right, still a bit lean somewhere, the things I said before could be the cause, or partially blocked jets...did you look at the holes in the jets through a magnifying glass, are they perfectly clean? i have a new idle jet in.ive tried switching jet for jet from the old broken carb i have which i boiled,poked with a strand of wire brush,blew out with air gun and sprayed with carb cleaner.but as you say somethings not right but fucked if i can find it Link to comment Share on other sites More sharing options...
skik Posted September 22, 2010 Author Share Posted September 22, 2010 so that cofirms it then , it's a carb issue and its fuel starved when you snap open the throttle quickly. However much you think you have fettled this carb, something still isnt right, still a bit lean somewhere, the things I said before could be the cause, or partially blocked jets...did you look at the holes in the jets through a magnifying glass, are they perfectly clean? i took carb off AGAIN today.completely striped it.jets,choke and mixture screw out.cleaned everything,blew it out,put it back together exactly the way haynes manual tell you,and guess what.JUST THE ****ING SAME.im beat Link to comment Share on other sites More sharing options...
Moderator drewpy Posted September 22, 2010 Moderator Share Posted September 22, 2010 i took carb off AGAIN today.completely striped it.jets,choke and mixture screw out.cleaned everything,blew it out,put it back together exactly the way haynes manual tell you,and guess what.JUST THE ****ING SAME.im beat you need to get it ultra-sonically cleaned you will be amazed whatcomes out after that. Mervin does the service if you can stand the wait (he lives in Devon) Link to comment Share on other sites More sharing options...
skik Posted September 22, 2010 Author Share Posted September 22, 2010 you need to get it ultra-sonically cleaned you will be amazed whatcomes out after that. Mervin does the service if you can stand the wait (he lives in Devon) pity im in n.ireland.what is ultra-sonically Link to comment Share on other sites More sharing options...
Moderator drewpy Posted September 22, 2010 Moderator Share Posted September 22, 2010 pity im in n.ireland.what is ultra-sonically ultrasonic uses sounds waves to vibrate crud off things, used in jewerly and dental applications Link to comment Share on other sites More sharing options...
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