My bike had a fit and I can't figure out why
Discussion
I own a Yamaha YBR 125 2006 (carb)
So there I was riding home when I shifted up a gear and my engine just sort of went 'limp' and started dying. It continued 'running' albeit very badly until I came to a halt but there was no power coming from it (throttle unresponsive).
So I push it to a pavement and spend about 15 minutes. kicking the bloody thing trying to get it to start. Trying with choke and no choke, throttle and no throttle. It took 15 minutes to finally start it and then it cut out after about 5 seconds.
I think maybe my fuel gauge is broken and I've ran out. Luckily there was a petrol station down the road so I push it to that. Fill it up and it takes about 4 litres, so it clearly wasn't empty.
Manage to get it started (only the third or fourth kick this time). Get moving, pull out of the petrol station and on to the road. Pretty much as soon as I start to accelerate faster than 10/15mph it just cuts out again. Exact same thing. So I push it on to the pavement again.
Spend another 15 minutes kicking it trying to start it. This time when it finally started I let it 'warm up' (even though it should already have been warm) for about five minutes.
I took it home (about 1-2 miles) only in first gear as I was worried it was an issue with shifting up. Finally get it home and take it round the block shifting up to second....... Literally no problems, rides like normal.
The only thing that has changed is that I tried shifting without the clutch today after reading some advice about sequential gearboxes on various forums. I was pretty confident that I was getting the hang of it as most of my shifts were smooth.
Also, the bike was in a crash about a month ago, and did have petrol in the oil sump. It was recommended that I should change the oil and it'd probably be fine. So I did change the oil a couple weeks ago and it has been fine until today.
It's also worth noting that sometimes the bike is *really* difficult to start, but I've mostly just put this down to it being carburretted and my being a learner.
So what could have caused this to happen and then seemingly/hopefully disappear? Could I have done something wrong?
So there I was riding home when I shifted up a gear and my engine just sort of went 'limp' and started dying. It continued 'running' albeit very badly until I came to a halt but there was no power coming from it (throttle unresponsive).
So I push it to a pavement and spend about 15 minutes. kicking the bloody thing trying to get it to start. Trying with choke and no choke, throttle and no throttle. It took 15 minutes to finally start it and then it cut out after about 5 seconds.
I think maybe my fuel gauge is broken and I've ran out. Luckily there was a petrol station down the road so I push it to that. Fill it up and it takes about 4 litres, so it clearly wasn't empty.
Manage to get it started (only the third or fourth kick this time). Get moving, pull out of the petrol station and on to the road. Pretty much as soon as I start to accelerate faster than 10/15mph it just cuts out again. Exact same thing. So I push it on to the pavement again.
Spend another 15 minutes kicking it trying to start it. This time when it finally started I let it 'warm up' (even though it should already have been warm) for about five minutes.
I took it home (about 1-2 miles) only in first gear as I was worried it was an issue with shifting up. Finally get it home and take it round the block shifting up to second....... Literally no problems, rides like normal.
The only thing that has changed is that I tried shifting without the clutch today after reading some advice about sequential gearboxes on various forums. I was pretty confident that I was getting the hang of it as most of my shifts were smooth.
Also, the bike was in a crash about a month ago, and did have petrol in the oil sump. It was recommended that I should change the oil and it'd probably be fine. So I did change the oil a couple weeks ago and it has been fine until today.
It's also worth noting that sometimes the bike is *really* difficult to start, but I've mostly just put this down to it being carburretted and my being a learner.
So what could have caused this to happen and then seemingly/hopefully disappear? Could I have done something wrong?
I'm wondering if when it was on its side it got engine oil in the carb and air filter. Might be worth having a look. When I tipped my rotary lawnmower on its side a year ago to clean the compacted grass out of the underside it filled the air filter with oil and needed a good clean out before it ran ok again.
I'd speculate there could be water in the float bowl. OP remove the carb and have a look inside. Fuel floats on water. Also check the float and needle are working correctly. You do this by inverting the carb and blowing down the fuel pipe. When you lift the float by hand the needle should close the fuel supply into the float bowl. The float should move freely on it's pivot pin.
What does the spark plug look like? Is it brown and fluffy, black and sooty or maybe black and oily? Does the bike have smoke coming from the exhaust pipe?
What does the spark plug look like? Is it brown and fluffy, black and sooty or maybe black and oily? Does the bike have smoke coming from the exhaust pipe?
Edited by Boosted LS1 on Wednesday 14th November 16:54
From experience, same symptoms.
1) some bas*ard stuffed leaves in my petrol tank in 1978., so blockage in tank problem.
2) modern fuel has a horrible effect on fuel lines, we have seen them swell up and /or dissolve and block the system and jets. Even seen a fuel line explode on a Harley efi when the engine coughed!
1) some bas*ard stuffed leaves in my petrol tank in 1978., so blockage in tank problem.
2) modern fuel has a horrible effect on fuel lines, we have seen them swell up and /or dissolve and block the system and jets. Even seen a fuel line explode on a Harley efi when the engine coughed!
Thanks for everybody's replies. I went through and looked at the carb again and couldn't find anything wrong with it. I decided to replace the battery since it seemed like the weakest link in the ignition system and it worked!
Not only does my bike now start every time but the starter motor now works too (it hasn't worked while I've had the bike at all). Better result than I could have hoped for really.
Now let's just hope it stops bloody raining
Not only does my bike now start every time but the starter motor now works too (it hasn't worked while I've had the bike at all). Better result than I could have hoped for really.
Now let's just hope it stops bloody raining
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