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post #1 of 50 (permalink) Old 07-18-2008, 06:13 AM Thread Starter
 
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Loss of Power

Hey guys, I'm worried that something is mechanically wrong with my bike. While riding at just over 60 mph yesterday my bike died right on the highway. I was in 4th, and was holding it just below the powerband (about 7k rpm's). As I started to accelerate just slighty (bringing it to 7.5) it completely stopped pulling. Wtf? I mean, I twisted the throttle and there was absolutely no response, nothing. I wish I had listened to the bike a little more right off the bat but I thought I had a flat tire from the way the bike was wobbling so badly and losing speed. By the time I had gotten over into a turn lane the bike was just struggling and coughing before finally cutting itself off. I tried to start it back up (afraid I had blown the motor or something) and it just sounded horrible and wouldn't start. Eventually I managed to get it going by revving it really high while I kept pushing the starter button.

I have never heard of anything like this before and I'm disappointed to lose a little bit of trust and reliability in my bike. To rule a few things out, I had plenty of fuel (which was 'on') and my oil level is fine and was changed not too long ago. I'm completely lost as to what happened and why it's now running just fine, like nothing's wrong.

Also, if someone could please tell me what would happen if it did this again and I happened to be cornering, I'd appreciate it. I would have thought it would be a smooth deceleration in the first place but that wasn't the case.
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post #2 of 50 (permalink) Old 07-18-2008, 06:54 AM
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In a corner you'd have little choice but to stand it up and try to bring it to as abrupt a halt as possible, unless you think you could finish the corner coasting; if the engine died, pulling in the clutch and standing it up as it slowed would be one possibility.

As for causes, I had a similar issue with my first bike just before I crashed it. I had cleaned the carbs pretty thoroughly and didn't seem to resolve the issue. It could be that your fuel tank's vacuum breaker is clogged and after riding it a while the vacuum in the tank is preventing fuel flow. Does it start up now and only die when its well-warmed?

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post #3 of 50 (permalink) Old 07-18-2008, 07:35 AM
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Yea in a corner when things go wrong like that the clutch is your best friend even if your not in a corner it can be your pal in bad times.

At first I was thinking you have a fuel/air problem but the wobbling and bad sound when trying to start it makes it seem like it might be worse than a simple fuel/air issue. Is it still problematic?

Not enough info to diagnose but I will say if the engine gets flooded with fuel the bike is hard to start back up unless you open the throttle or let the bike sit and evaporate the fuel. But rarely does a bike cut off from excessive fuel while cruising, it'd bog down before it did though. Too little fuel would cause a starving sensation and eventually die.
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post #4 of 50 (permalink) Old 07-18-2008, 07:52 AM Thread Starter
 
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Does it start up now and only die when its well-warmed?
It starts right up now and runs like normal. I took it out for about an hour after I had it going again yesterday evening to see if it was going to die on me again.. I ran it really hard most of the time and it seemed to be fine. That's why I'm so confused, I don't know if it needs to go to a shop or if it's fine...? I did just fill it up at a little country gas station that I had never been to before, I always use premium though... Maybe they had bad gas or something?

Last edited by RydeAddict; 07-18-2008 at 07:55 AM.
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post #5 of 50 (permalink) Old 07-18-2008, 08:36 AM
 
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I'm guess its a fuel problem, ignition problem ussually dont go away on their own, but tend to stay.

Possible causes.
1. Got bad gas with tons of water in it. If thats the case, it shouldn't happen again
2. Obstruction in the air flow. Check around the air filter to see if there is a bird or a squirell or something in there. It would have to be big
3. Something blocking the vent lines on the tank. If it happens again, stop and open the gas tank lid. If the problem goes away, thats the problem. Look for kinked houses.
4. A piece of gunk in the carburator blocking the jets. This could have dissolved by now, or it could float away from the jet then come back later. You would have to take apart and clean the carbs. Also, drain the gas, and check the inside of the tank for rust, or other debrees..
5. Maybe the choke was left on? Sounds extreme, but who knows...



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post #6 of 50 (permalink) Old 07-18-2008, 08:53 AM Thread Starter
 
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3. Something blocking the vent lines on the tank. If it happens again, stop and open the gas tank lid. If the problem goes away, thats the problem. Look for kinked houses.
You might be onto something.. Before I got it running I had opened the lid to look and see how much gas was in there. I closed it and that's when I got it to crank. The choke was off too. Are these hoses easy to see (I don't have the bike with me right now) or does it require taking off fairings?
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post #7 of 50 (permalink) Old 07-18-2008, 08:58 AM
 
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They are under the tank. On most bikes you have to take off the back seat, which will give you access to the screws holding the tail section. Once the tail is removed (sometimes all, sometimes partially) you can get to one bolt that holds the back of your saddle. Take that out and the saddle should slide out (its hooked under the tank). The saddle covers one bolt that holds the tank on, it is hooked around rubber thingies close to the steering head. You should be able to lift the tank by pivoting it. Place a board or something to keep it from going back, and have a look see.



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post #8 of 50 (permalink) Old 07-18-2008, 09:29 AM Thread Starter
 
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Oh this is going to be interesting.. Good info, thanks!

(Though you did leave out, 'take pictures so your dumb ass can put it back together.')
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post #9 of 50 (permalink) Old 07-18-2008, 11:16 AM
 
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Its not that bad....



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post #10 of 50 (permalink) Old 07-18-2008, 02:57 PM
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Take pictures of your dumb ass.





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