Bike won't start. Please help!

[ace16a]

Put new cbr led tail light on a couple nights ago and was messing with the front led turns to adjust the flash rate. Started it up last night to see how the lights looked and shut it down. Ran for a couple of minutes. Went to start it this morning and it just cranked. Tried starting fluid and dumping fuel into carbs but gave up cause I had to get to work. Got home this afternoon and it still just cranks. Has newer ngk plugs, has spark at all plugs, clean fuel came from carb bowls, fuel pump is pumping fuel as far as I can tell. Has air, fuel, and spark but still won't start. I'm very confused. Could I have messed something up when I was working with the blinkers? Any sugestions are appreciated.

 

[Ratt1eHead]

Check your fuses... and you said you have spark? This might sound stupid, but did you maybe bump the kill switch?

 

[ace16a]

All fuses are good. Kill switch in run position.

 

[Miles Long]

With fuel and spark, it should be "good to go", providing it is turning over fast enough (have you tried jump-starting from a car?) and the ignition timing is correct. In any event, avoid long starting attempts with a weak battery. Many think that this long, slow grinding is what contributes to starter clutch failure...very common with these bikes.
Could something related to the throttle cables or choke operation come unhooked, or binding? Check for this at the carbs themselves.
What did you do when "messing" with the flash rate? Did you have the left hand scoop off?
Cheers!

 

[ace16a]

Checked all the cables, nothing is binding. Didn't have the scoop off till the no starting problem, just the wires behind the headlight. I have read about starter motors developing problems from prolonged usage so I don't crank it over for more than a few seconds, haven't wore the battery down yet. I'm going to pick up a new set of plug on my way home from work this morning and see what happens. I know the carbs are rich so may the plugs are bad already. Kind of seem like they aren't firing.

 

[davesax36]

Charge your battery and check spark gap. . 31-35 for stock coils. Sometimes when the battery gets just low enough the spark is too weak.

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[Miles Long]

If the bike was running well before the electrical mods, and you still have a strong spark at the plugs, I can't imagine this "no start" as being electrical in nature....however...
first thing I would do is return everything to as it was before the mods. Seems to be too much of a coincidence that the problem began immediately after making the alterations.
Keep us posted

 

[Rollie]

If the bike was running well before the electrical mods, and you still have a strong spark at the plugs, I can't imagine this "no start" as being electrical in nature....however...
first thing I would do is return everything to as it was before the mods. Seems to be too much of a coincidence that the problem began immediately after making the alterations.
Keep us posted

+ 1 on returning to " prior to mod " state. You may very well find the problem while un-doing the mods.

 

[ace16a]

Thing thing that gets me is that the bike was running after the mods. It didn't start till the day after everything was put back together and the bike was running. I've had the battery on a trickle charger for the past week while working on the tail light. It's full charged and is about 10 months old. Every once in a while it sounds like a cylinder is firing and it's trying to start. I don't think it's fuel related. I took the pump loose and ran it, shot fuel right out and I could build a little pressure by pluging the hose end with my finger. I drained all the float bowls and tried starting it. All the bowls were full again. The only concern I have with the pump is that I can't tell if its running while cranking the motor. It primes when the key is turned on and that's all I can tell for sure. I don't really feel anything when I touch the pump while cranking.

 

[davesax36]

Crack the throttle while it's cranking? I do this to mine once in a while when it's acting up.

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[Miles Long]

If the bowls fill before attempting a start, the bike should at least fire up, then eventually die, if the pump is defective.
If the problem is fuel-related, the only other thing I can think of is "bad gas". Is this a possibility? Did you last fill up at a seldom used station?
You said that you were going to pull and check (condition and gap) the plugs. Let's see what you find.
Probably something very simple . Keep the faith!

 

[ace16a]

Got it. Fuel filter was very dirty so I change that and new plugs and she started up with a shot of starting fluid. Now it starts up just fine. Going to wait an hour or so and I'll try it again. I think the cylinders got flooded and fouled the plugs when I went to start it yesterday morning. Thanks for everyone's in put. I got a little more familiar with the fuel system now.

 

[Rollie]

Thing thing that gets me is that the bike was running after the mods. It didn't start till the day after everything was put back together and the bike was running. I've had the battery on a trickle charger for the past week while working on the tail light. It's full charged and is about 10 months old. Every once in a while it sounds like a cylinder is firing and it's trying to start. I don't think it's fuel related. I took the pump loose and ran it, shot fuel right out and I could build a little pressure by pluging the hose end with my finger. I drained all the float bowls and tried starting it. All the bowls were full again. The only concern I have with the pump is that I can't tell if its running while cranking the motor. It primes when the key is turned on and that's all I can tell for sure. I don't really feel anything when I touch the pump while cranking.

I figured it wasn't the filter if you had gotten this far.