Bam1979 Posted October 6, 2011 Share Posted October 6, 2011 Hi folks im wondering if anyone can help me? I have just bought a xv125 Virago on a W/2000 plate. Just mot'd it and it started running rough then fine again. Then he next day it wouldnt start. Finally got it started and it wont rev properly or go above 25mph. Carb now taken off and cleaned thoroughly and its starting now on the button but still wont go above 25 mph. Im stumped any ideas folks??????????? Link to comment Share on other sites More sharing options...
Moderator Airhead Posted October 6, 2011 Moderator Share Posted October 6, 2011 you say carb was cleaned "thoroughly" Bam, yet this does sound rather like a blocked main jet possibility, did you look through the mj...is it clear? Link to comment Share on other sites More sharing options...
Dickwad Posted October 6, 2011 Share Posted October 6, 2011 Have you checked the fuel tap, try it on reserve, or take the fuel pipe off the carb, let it flow into a bottle or jar and watch for a steady strong flow,do this on reserve as well, if all is well, then you know its not that, if it does make a difference, and you have restricted flow, then remove the tank and thoroughly clean it and the tap. and you will need to clean the carb again. oldgitonabike is probably right, but, the only way dirt gets into the jets, is from the tank, so check the basics first. just a thought, has your bike got a restricter of some kind in it, to make it legal for moped riders, im not to up on the new power restrictions for 125s, so I might be talking do-do. Link to comment Share on other sites More sharing options...
Bam1979 Posted October 6, 2011 Author Share Posted October 6, 2011 All the bits in the carb were taken apart and sorted right out as for the tap its running freely. My mate suggested a sensor on the carb cos when you take the lead off it makes no difference at all. The bikes done under 5k and always been kept inside til i got it Saturday. Could it need a new carb alreday??? Link to comment Share on other sites More sharing options...
Moderator Airhead Posted October 6, 2011 Moderator Share Posted October 6, 2011 oh your carb has a sensor! its no doubt a TPS and i've no idea what to do with it...never had the need to find out, it is no doubt in the manual...maybe a resistance reading check? Link to comment Share on other sites More sharing options...
Bam1979 Posted October 6, 2011 Author Share Posted October 6, 2011 Whats a TPS? Link to comment Share on other sites More sharing options...
Moderator Airhead Posted October 7, 2011 Moderator Share Posted October 7, 2011 Throttle Position Sensor Link to comment Share on other sites More sharing options...
Bam1979 Posted October 7, 2011 Author Share Posted October 7, 2011 I should have warned you bud I'm not the sharpest spoon in the knife draw. What are the chances of me getting a sensor or will I have to get the complete carb do you reckon? Link to comment Share on other sites More sharing options...
Moderator Airhead Posted October 7, 2011 Moderator Share Posted October 7, 2011 Bam i'm not saying you need a new sensor,... no way a new carb i'm just guessing (and thats all it is) about this sensor on your carb...I may be wrong I have no experience of them. I suggest that if you can...get a manual and see if you can do any checks on it? Link to comment Share on other sites More sharing options...
neversaydie Posted October 7, 2011 Share Posted October 7, 2011 New carb? Unlikely Throttle position sensor. Hmmmmmm, cant be certain, and I could be wrong but, unlikely Restricted? Doubt it, only 11 bhp Try the easiest and cheapest possibilities first Spark plugs and leads/air filter/are both cylinders firing/if theres a rubber sleeve onto the carb does it have splits or cracks in it/stiff throttle cable/timing Link to comment Share on other sites More sharing options...
Bam1979 Posted October 8, 2011 Author Share Posted October 8, 2011 Plugs, leads, and filters all checked and are practically brand new. Slight perishing crack in inlet rubber but its only surface so is not sucking air. Throttle cable is ok. So ill check both cylinders and timing today thanks people I really appreciate all your help. I might even get some pics uploaded if I finish work early enough today. Link to comment Share on other sites More sharing options...
Bam1979 Posted October 9, 2011 Author Share Posted October 9, 2011 The guy i bought the bike of who is also a mate had a look at it yesterday and said the plug on the back cylinder is dodgy so ive ordered a pair cos no one holds them in stock round here. But would a dodgy spark really cause this mush grief? Link to comment Share on other sites More sharing options...
Moderator Airhead Posted October 10, 2011 Moderator Share Posted October 10, 2011 if a plug is dodgy it is likely to go down completely, yeah that would do it as far as 25mm top speed goes but it would also 'not sound right' or feel right for that matter! Its an easy one to test , when the bike is running dab the exhaust header with a damp rag, the running cylinder will have a hot exhaust and you will hear the hiss of the damp rag touching it, obviously a cylinder not firing will have a cool exhaust so this wont hiss. Its a good method of diagnosing cylinders that are not firing on multi-cylinder bikes. dont be dabbing any heat shields if they are fitted, you need to get to the pipe as it exits the cylinder if poss Link to comment Share on other sites More sharing options...
Bam1979 Posted October 11, 2011 Author Share Posted October 11, 2011 How stooooooopid do I feel??? It was the plugs. What a twonk eh? But I would like to thank everyone that posted advice and help on this one guys you helped me right out. Thanks again fellas. Link to comment Share on other sites More sharing options...
Recommended Posts