bikingcodger Posted August 1, 2012 Share Posted August 1, 2012 Hi guys, new member here could do with a little help. My sons '98 virago vx 125 ( bought last week) was running a little rough, seemed to be fuel starvation at higher revs. I stripped the carb down today and found the fuel injection tube (if thats what it's called) that protrudes into the main throttle body and supplies fuel under acceleration and on open throttle ( its fed through a galley in the bottom edge of the float chamber mating face and supplied with fuel direcly via the plunger pump on the side of the float chamber) was completely blocked. It looked as if someone had tinkered previously as the end of the tube was a bit mangled and crushed (pliers maybe) and the exposed screw head of the jet was sheared off so I couldnt get it out to try and clear it. I searched the web without success for a carb diagram showing this part, and after 2 hours with an airline and some yard brush bristles had no choice but to put another hole a little further along the tube, before the blockage. It wasnt an exact science,theres no access from below to put the new hole in line with the original and so the fuel now squirts sideways rather than downwards through a slit that is substantially bigger, I suspect, than the original pin hole. It runs much better at high revs now, but theres a tiny hesitation when its revved from tickover and I'm guessing that its now dumping a little too much neat fuel. I cant find this part on any website, Its not even shown on the exploded diagrams Ive found so far. Is it a replacable part? or will it only come fitted to a new carb body? A new carb seems to be in the £700 region, the bike was only £900. Seen a few used carbs on flea-bay but they look a bit tatty and may be no better. Any suggestions anyone? All help gratefully recieved! Paul Link to comment Share on other sites More sharing options...
TheBoltons Posted August 3, 2012 Share Posted August 3, 2012 Hi Paul - I had a similar issue - is it the main jet? It's a little screw that is attached to the main nozzle that feeds down into the carb body - if so, it IS a replacable part, for no more that a fiver usually - but if you have placed a hole in the nozzle as well, you will need to buy a new main nozzle as well - no point searching ebay for a bike model specific part, just search "main jet carburetor" or "main nozzle carburetor" and get one the right size. hope that helps. Link to comment Share on other sites More sharing options...
bikingcodger Posted August 5, 2012 Author Share Posted August 5, 2012 Thanks for that info, though not certain its the main jet. I could br wrong (it has been known) bit I thought the main jet was the large screw in one in the bottom of the carb body. I'll check it out anyway, though since its gone back together it seems to be running fine. My lad reports a top end of around 58mpg and decent acceleration so may end up not interfering again if he's happy with it. Paul Link to comment Share on other sites More sharing options...
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