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Discussion Starter #1
Here is what is happening. I was riding along the other day and all of the sudden I lost power, not all power the bike didn't die or anything it just felt weak and I really had to throttle it to maintain speed. All of the sudden all the power kicked back in and it was all good again. No fi light flashing or anything. Fast forward to when I leave work that afternoon. I pull out of the parking lot at work and when I get to the first light while sitting there I notice the rpm's drop from 1300+/- to just below 1000 and as I start to take off again I have to really throttle it to get it moving and the bike is crazy sluggish again. Then again all of the sudden full power kicks in and Im off. But this time it did it maybe 5 times causing the bike to die twice and leave me stuck on the side of the road for a few minutes trying to keep it going. I got it going enough to pull out of a gas station and right on to an on ramp and once I got on the highway all the power came back and it didn't act up again the rest of the way home, about a 20 mile trip.

A motorcycle mechanic buddy of mine says it sounds to him like I have a coil going out and when it acts up it's only running on one cylinder. Makes sense because the bike doesn't lose all power.

What do you guys think, any ideas?
 

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A motorcycle mechanic buddy of mine says it sounds to him like I have a coil going out and when it acts up it's only running on one cylinder. Makes sense because the bike doesn't lose all power.
i think hes headed down the right path... failing coil, plug, or as ldh said a bad battery connection. i had a buell that did something similar and it was in fact a loose battery connection
 

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I had something similar happen to me and, with 4 cylinders, it was harder to identify. I filled a small squirt bottle with water and put it in my tank bag. The next time it lost power, I gave it a minute and then pulled over. I squirted each of the header tubes, a few inches out of the head, and you can clearly see what is firing and what is not. The firing cylinder will evaporate the water before it can touch the metal. A dead cylinder will allow the pipe to get wet and take a few seconds for the water to evaporate. Once you know which cylinder is the problem, you are almost there!
 

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Discussion Starter #5 (Edited)
Battery cable lead is not tight enough on one of the posts...
i think hes headed down the right path... failing coil, plug, or as ldh said a bad battery connection. i had a buell that did something similar and it was in fact a loose battery connection
But wouldn't a loose battery cable cause the bike to lose all power temporarily? I still have power but the bike gets weak when whatever is happening happens. Either way I didn't have time on Friday to pull the seat off and check the cables but I'll check em for sure when I get home this evening. I may go ahead and order a couple of new coils anyways. They're only $40 a piece

Thanks guys
 

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But wouldn't a loose battery cable cause the bike to lose all power temporarily? I still have power but the bike gets weak when whatever is happening happens.
No, because what you are experiencing is intermittent loss of power as the bike vibrates at certain rpms enough to cause a very quick disconnection and reconnection of the current for x amount of time.

Fluorescent lightbulbs cycle on & off 60 times per second, but you don't notice it because it happens so quickly.
 

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Discussion Starter #8
No, because what you are experiencing is intermittent loss of power as the bike vibrates at certain rpms enough to cause a very quick disconnection and reconnection of the current for x amount of time.

Fluorescent lightbulbs cycle on & off 60 times per second, but you don't notice it because it happens so quickly.
Interesting


I'll check it out when I get to the house and let ya know.

Thanks again
 

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Discussion Starter #10
Ok I checked the battery cables at the posts and the connections on the side and everything was good and tightened down
 

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Check the connector on the harness leading to the main fuse by the battery, although if it runs on one cyl, then it's unlikely to be just that. Did you check the connections to the CDI? I had a problem with blowing CDI units because of bad wiring there (From previous owner). Once sorted, it's been good as gold. Carefully checking wiring connections & earths would be the way to go first.
 

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How much voltage do you have when the headlights are on highbeam at 5000 rpm? Not more than 15.5V.
How much at Idle? not less than 13.4V.
If you're outside those parametres, you have a problem with the r/r or stator.

Especially if you're low on voltage, that could cause abrupt interference like you describe.
 

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Discussion Starter #13
Check the connector on the harness leading to the main fuse by the battery, although if it runs on one cyl, then it's unlikely to be just that. Did you check the connections to the CDI? I had a problem with blowing CDI units because of bad wiring there (From previous owner). Once sorted, it's been good as gold. Carefully checking wiring connections & earths would be the way to go first.
I'm going to pull all the plastics off this weekend and go over all the wiring. I now have an issue with my blinkers. They all stay on like running lights and the blinker indicator on the gauge stays permanently lit. They still blink but they're always on.

How much voltage do you have when the headlights are on highbeam at 5000 rpm? Not more than 15.5V.
How much at Idle? not less than 13.4V.
If you're outside those parametres, you have a problem with the r/r or stator.

Especially if you're low on voltage, that could cause abrupt interference like you describe.
You're speaking Greek to me:). I can turn wrenches with the best of them but when it comes to electricity I know nothing. The previous owner did mention that he had to replace the stator about 3 months ago though so you might be on to something
 

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I don't know what LDH had in mind, he knows these bikes inside out.
Not to step on anyone's toes here, but with the multi-meter check the voltages I listed above. Check the connectors for the R/R to see if there's any corrosion or signs of burn. Put a dab of die-electric grease when you reconnect them.
 

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Discussion Starter #17
I don't know what LDH had in mind, he knows these bikes inside out.
Not to step on anyone's toes here, but with the multi-meter check the voltages I listed above. Check the connectors for the R/R to see if there's any corrosion or signs of burn. Put a dab of die-electric grease when you reconnect them.
I have to go to Home Depot tonight to pick up some things for a bathroom remodle im doing so I'll get a multimeter tonight.

Thanks for the help
 

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Discussion Starter #18
I scored the meter last night and will be checking voltages in the am. I'll let you know my results.
 
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