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Discussion Starter #1
i was riding home yesterday and the bike started acting funny. if i gave it full throttle, it wouldnt accelerate. just stayed at the same RPM and sounded like it was misfiring. if i slowly rolled on it would go though.

so a few miles down the road, still out in the country, i was doing about 60 or 65 or so and it just died. i pulled over and it fired back up, so i took off again. same full throttle problem, but i just kept it smooth so that wasnt really an issue. got back up to about 60, died again. got it fired back up while i was still rolling... got back up to about 60 and it died again.

so i got it going, and limped it home about 45 or so.

got it home and it would idle fine, and ride fine, except when i got it up to speed, and the full throttle thing.

so i took the carbs apart, made sure everything was clean. no clogged jets or anything like that. i just cleaned them like a month ago, and they were still pretty clean.

i adjusted the float height, and checked the fuel level and set the pilot screws.

put the carbs back on, and it fired up, but was idling low and died. started right up and with bit of throttle and it would run, but was still idling very low. before i could get my hand under there to adjust the idle, it died again.

now it wont start at all. throttle or not. i checked the petcock, and it was working fine. there was fuel in the bowls too.

so now im boned. what should i look at next? im gonna pull the plugs and look at them after dinner, but id bet they are fine, as they are only about two weeks old.

ignition system? still a carb problem?
 

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Discussion Starter #3
you mean when i checked the fuel level in the carbs? i dont think it did, but then again, i wasnt really paying attention.
 

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Discussion Starter #5
when i said checked the fuel level, i meant in the carbs. but i did open the tank at one point, b/c i thought i remembered reading something about that on this site. didnt hear any noise.
 

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i still think it's the fuel cap vent. did you back flush the fuel line? ARE YOU SURE the pilots are clean? The petcock functions properly? does the problem go away if you switch to reserve?
 

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Discussion Starter #9
yeah definetly the pilots are clean. fuel line was back flushed when i cleaned the carbs last time.

tried it on ON, PRIME and RESERVE. still no start :(
 

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Lets check your battery voltage 12.6 right? if not charge it and then recheck. Then let us know.
 

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Discussion Starter #13
battery is fully charged. im going to start checking wires today, but i dunno... it seems like a carb problem to me, since it ran for a minute or two before sputtering out. then it just wouldnt start at all... i know wires break and stuff comes disconnected, but it was sitting on the centerstand in my garage, and im not rly sure how something would come undone like that.
 

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I would look at a couple of things first be sure you carb vent tube is clear or better thrown it away. Open the tank cap. check for fuel in the carb bowls. be sure the Idles setting is open a little crank the engine in this condition and witness the fuel level in the carbs. (crenk 3 sec wait 10 crank 3 wait 10) fit a clear piece of tubing on the carb drain and run it up along side the carb the fuel level should be right the split line. DOn't touch the throttles at any time if all that goes well it will start.

FOG
 

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Water in the gas? Or lots of ethanol content that sat for a while? Sometimes fresh gas really helps in these cases.
 

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It could be a missfireing in one cilinder or you have foueld a spark plug i had that issue and it was doing the same thing it would only reach around 6o
 

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Discussion Starter #17
well. i went out yesterday, after letting it sit all night, and it fired right up ???

i let it warm up and set the idle. starts fine now. checked the fuel level, and its within specs. checked the plugs and they are fine. both coils produce a spark...

so after she warmed up i took it out for a little spin. seemed to run a bit better, but it started to rain so i only got about 5 miles on it.

still has the same full throttle problem though. wants to miss and sputter when it gets to WOT when its under load. if its in neutral it will rev freely.
 

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Mine did the same exact thing on the track last weekend- culprit- out of gas! This leads me to believe it is a fuel issue- not electrical. One thing you did not mention was is the air filter clean and unobstructed?

Did you discon the fuel line at carbs and have fuel run freely from the tank?

Bad gas rarely effects the main jet especially when it was running and not sitting. Is there afuel filter installed? If yes- does it flow properly?

Float hight like FOG said is important to check. At lower rpm, everything could be kosher but as the engine asks the carbs for more fuel, if it is not there it will not get it.

Assuming that valves are not making any noise and that they have been properly adjusted. Have you done any super high rpm (bouncing off the limiter) at all? A bent valve will mimic a fuel issue sometimes.

Being that I have flat slides and no airbox, and have never had a stocker: Does the stock air box have a main opening that could be getting clogged with say your registration (have seen it on other bikes.)?

Man am I reaching for straws or what!

Others asked about the battery, but since it fires up fine, and on a non- FI motor the voltage being low will not really affect it if the alternator is working.
Oh and forgot to add, did you check for an air leak at the boots between carbs and motor?
Good luck and let us know how it goes.
 

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dragknee said:
well. i went out yesterday, after letting it sit all night, and it fired right up ???

i let it warm up and set the idle. starts fine now. checked the fuel level, and its within specs. checked the plugs and they are fine. both coils produce a spark...

so after she warmed up i took it out for a little spin. seemed to run a bit better, but it started to rain so i only got about 5 miles on it.

still has the same full throttle problem though. wants to miss and sputter when it gets to WOT when its under load. if its in neutral it will rev freely.
Clean the insides of the plug boots.

FOG
 

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Discussion Starter #20
the air filter is new(ish) and unobstructed. nothing in the airbox, i dont think... ill double check, but when i had it all apart to get the carbs off, everything looked kosher.

fuel will run freely from the tank. i have a petcock with a prime setting, and it works fine. i know its sucking gas, because i rode it for 5 miles and it didnt die at all... if it wasnt pulling gas out, i dont think it would go very far on whats in the bowls lol.

no super high RPM either.

will check for air leaks, and clean the inside of the boots. what should i use to clean it FOG?

other than that im stumped. i thought maybe the timing isnt advancing correctly... but to really check that id have to have it on a dyno, which aint gonna happen lol. the problem only occurs when its under load, if its in neutral or on the center stand, it works beautiful.
 
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