Hi all,
Help needed, any opinions would be appreciated...
I recently bought an NSR250 in Thailand and it was in pretty bad shape. Initially it was running really rough and blowing a lot of smoke and it would drip oil from the join between the exhaust and cylinder. First thing i did was pull the carbs off and clean them, they were filthy, never seen anything like it... Put them back on and it started first kick and sounded much better but after warming up on low revs it was blowing heaps of smoke. Turned it off and the plugs were very oily. My thinking was the oil injection was feeding too much oil so I disconnected it and ran premix 30:1 (95 octane). It ran well on this and the smoke problem was fixed so I assume I was correct. The engine revved up all the way to 12000 and pulled hard from 7000 but it was sputtering under 7000.
The carbs were leaking a little petrol from the seals so i took them off again and adjusted the floats. I lost the 95 octane fuel as I put the fuel tank on the grass and it was not turned off properly (my foolishness). Anyway I put the carbs back on and this time put in 91 octane fuel with 5% ethanol. Started up sweet and took off with the engine feeling good for maybe 1 minute and then the engine cut out. Pulled over and gave it a kick and it started up again but after accelerating for a couple of gear changes it cut out again. This happened a few more times on the way home.
I looked up this forum and found that maybe it was electrical so I checked the battery with a voltmeter. With engine off its around 12.7v, engine on and its up to 14.2 or so, revving to 5000 and its up at around 14.6 and fairly steady. With the headlights on it goes down to around 12.9 at idle and up around 13.5 with the revs up. So I'm assuming the electrical side of things is ok.
I tried riding it a few more times and the same thing happened, it would run sweet for a minute or 2 and then cut out but it is now even worse. For a while it was better with the choke on but now choke on or off it doesn't want to go anywhere and I had to push it home.
So I'm wondering, could the wrong float setting cause these symptoms? Or low quality fuel? Or a mixture of both? Or could the carb jets be clogged again? Or could it be something else entirely? Any ideas??
cheers,
Tim