stevie16v Posted November 26, 2008 Share Posted November 26, 2008 Right, Story goes like this. I have been doing some work on an sr125 which has been sitting for a year. Finally got it (almost) up and running. Had it out a scoot last week and it was fine. i turned it off, 15mins later i went to go again, Made it about a mile and it started chugging then just died. re-started it. Made it about 50m, same again. This time i had to bump start it. Made it another 50m and it was a goner. so pushed it the mile home (yes it hurt) I put a new battery in it as i thought that was the problem. but no. I have stripped, cleaned and made sure the carb settings are all correct. Whenever i open up the throttle it will give a rev then nothing. Engine still ticks, i have to come off the throttle to do it again. When i go to move, it will do the same, Will build up speed to about 10mph, then theres no power, and it will chug again until it cuts out. This is my first bike and i have spent a fortune on parts, Im pretty downhearted by it. Can anyone suggest anything? Link to comment Share on other sites More sharing options...
Moderator Airhead Posted November 26, 2008 Moderator Share Posted November 26, 2008 Can anyone suggest anything? Yep...Dynamite Seriously though, you could do with some help and if you lived down my way i would do it Link to comment Share on other sites More sharing options...
wild foamy Posted November 26, 2008 Share Posted November 26, 2008 possibly its not moving off the idle jet onto the main jet, have you checked to make sure the jet is actually clear and not blocked? try changing the fuel also, i remember my dads' generator wouldnt go after about a years storage and it turned out to be sh*tty fuel Link to comment Share on other sites More sharing options...
stevie16v Posted November 26, 2008 Author Share Posted November 26, 2008 possibly its not moving off the idle jet onto the main jet, have you checked to make sure the jet is actually clear and not blocked? try changing the fuel also, i remember my dads' generator wouldnt go after about a years storage and it turned out to be sh*tty fuel Yup, its all fresh fuel. The carb is as clean as they get. To me it def sounds like some sort of fuelling problem. If i put the factory settings for the carb on eg idle, it just dies. I need to screw it in at least 1 turn for the idle to be high enough to keep it going. OLDGITONABIKE - If it wasnt in my mates garage in a residential street, there'd def be a stick of the banging stuff going right into the engine! lol Link to comment Share on other sites More sharing options...
wild foamy Posted November 26, 2008 Share Posted November 26, 2008 checked valve clearances and that sort of thing? gotta be fueling... are you getting a good spark? Link to comment Share on other sites More sharing options...
Moderator drewpy Posted November 26, 2008 Moderator Share Posted November 26, 2008 classic blocked main jet and emusion tube problem. got given a CG125 standing after 6 years, wouldn't rev without choke. used my trusty aldi ultrasonic bath and super dee dooper no more problems Link to comment Share on other sites More sharing options...
JimR Posted November 26, 2008 Share Posted November 26, 2008 Yup, its all fresh fuel. The carb is as clean as they get. To me it def sounds like some sort of fuelling problem. If i put the factory settings for the carb on eg idle, it just dies. I need to screw it in at least 1 turn for the idle to be high enough to keep it going. OLDGITONABIKE - If it wasnt in my mates garage in a residential street, there'd def be a stick of the banging stuff going right into the engine! lol Hi Steve, I guess the obvious has been done, compression check, valve clearance & cam chain tension ? If all those are correct you may want to check the electronic ignition is performing as it should, CDI dynamically adjusts the ignition curve so if its gone west you can get odd results - make you think its carb when its ignition. If these check out OK (this includes all connections & joints) then move to the carb. First off check fuel flow from the fuel tap ( and vacuum connection if the 125 has one ... from memory not but later model's may have this type of tap fitted (post '89)). Then run to the carb, First off remove the carb, inspect the manifold & gasket ( visual if on a budget as if removed you will need a gasket and a possible manifold) If the manifold shows no cracks and the cylinder head shows no yellow stains where the manifold joins you may deem these to be correct. As you have cleaned and set the carb to factory I guess that will be correct. With the distance ridden, is a scoot longer than a mile ?, and the restart (if within a short period of the scoot) will have all electrical components at the high end of their operating temp and if they have voltage applied to them (being on the edge of spec) may push one of the componets out of spec. If the first 3 parts of the 'flow chart' are not done redo those & go from there. Regards Jim Link to comment Share on other sites More sharing options...
stevie16v Posted November 26, 2008 Author Share Posted November 26, 2008 Jim, i havent checked compression and clearances etc as i dont have a compression tester, clearances i am just very uncertain on as it means removing bits that i dont know much about, so worried i mess something up. I think i've got a fair few things i'm going to need to check through now, I just need to figure out how to do it! lol Link to comment Share on other sites More sharing options...
JimR Posted November 26, 2008 Share Posted November 26, 2008 Jim, i havent checked compression and clearances etc as i dont have a compression tester, clearances i am just very uncertain on as it means removing bits that i dont know much about, so worried i mess something up. I think i've got a fair few things i'm going to need to check through now, I just need to figure out how to do it! lol Compression can be tested via putting your finger over the plug hole opening the throttle and pressing the start button if it hurts the compression is ok. If you have the guts to take the carb apart and get it together again valve clearences will be a dodle, cam chain is simple to check & I'm quite welcome to write a walk thro on how to do it ! Regards Jim Link to comment Share on other sites More sharing options...
stevie16v Posted November 26, 2008 Author Share Posted November 26, 2008 Compression can be tested via putting your finger over the plug hole opening the throttle and pressing the start button if it hurts the compression is ok. If you have the guts to take the carb apart and get it together again valve clearences will be a dodle, cam chain is simple to check & I'm quite welcome to write a walk thro on how to do it ! Regards Jim Jim, if you wouldnt mind, that would be a big help. I'm sitting just now writing out bits n bobs about what to check and roughly how to do it, Mainly electrical side just now. I have a manual for a ybr 125 but it isn't very clear. SO if you wouldnt mind doing that and anything else you can suggest i can pm you my email to fire it through to me Link to comment Share on other sites More sharing options...
stevie16v Posted November 27, 2008 Author Share Posted November 27, 2008 Time for positive post, Today i, stripped and rebuilt the carb again. check the spark etc, battery, throttle cable free play etc. Gave it another crank and still the same, so i thought, last resort, empty the fuel tank again, so, done it again. put 5l of fresh fuel in and like magic its going like a dream. Didnt take it out a good run yet tho. Sprayed some carb cleaner through the air filter housing whilst revving it and that took out some wee lumps aswell. So, going to take it a decent spin tomorrow, and touch wood. All will be good Link to comment Share on other sites More sharing options...
JimR Posted November 27, 2008 Share Posted November 27, 2008 Time for positive post, Today i, stripped and rebuilt the carb again. check the spark etc, battery, throttle cable free play etc. Gave it another crank and still the same, so i thought, last resort, empty the fuel tank again, so, done it again. put 5l of fresh fuel in and like magic its going like a dream. Didnt take it out a good run yet tho. Sprayed some carb cleaner through the air filter housing whilst revving it and that took out some wee lumps aswell. So, going to take it a decent spin tomorrow, and touch wood. All will be good Thats good !!! Regards Jim Link to comment Share on other sites More sharing options...
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