lust rebuilt the petcock about 2 months ago!

 

okay, no responses in a couple days but hers the story from today.....
Woke up this morning and went straight outside to try and crank the CBR, no go she wouldnt fire for ANYTHING! Got frustrated and went to church. Got home and figured id try and crank her, turned the choke on and hit the starter BAM she fired right up! only factor i can see now is the temperature, in the morning right now where i am its close to 40 degrees F, when i got her to crank it was at least 75F. What can i do to help with cranking in the cold?

 

Try richening up the pilot screws a 1/4 - 1/2 turn. Not too much as it will affect your overall performance. You could check the choke cable to make sure you don't have too much slack at the carbs. You are supposed to align the groove on the cable end with the edge of the clamp. Mine actually is lined up slightly inside the clamp. Cable stretch maybe.

 

guess ill be ripping the carbs off yet again today to clean and mess with the pilot screws a bit, I wouldnt be soo pissed if the bike simply didnt run at all, just makes me mad that itll work sometimes and wont others but when she runs she runs great.

 

Motion Pro makes an adjustment tool with bits for the pilot screws. Or you can slot the screw heads when you have the carbs off. I had to take mine of at least 10 times to get mine to run the way I wanted. I actually got good at it. I also kept the side fairings off to ease tank removal.

Definitely check the choke cable. If it is too loose it makes starting in cold weather a pain.

 

okayyyyyyy, still not working, i completely dismantled the carbs and soaked them in carb cleaner, reassembled and still the same exact problem. Im moving on to spark or compression now, what are the chances of bad coils?

 

I'm beginning to wonder if you've got a battery issue. Your "wont crank when cold, will when warm" is exactly what happened to the Yamaha FZ1 (1st gen carbed bike) I babysat last winter. It would crank eventually, but sometimes would take several minutes of trying, or only with a battery charger connected to the battery. It was turning the motor over, but the spark quality must have sucked. Threw a new battery in it on a 40 degree night, and it never was a problem again for the rest of the winter.

 

i have a friend stopping by with his f3 tonight so were gonna swap some parts around. Took the batt to autozone and they said it was fine so im assuming the batt isnt the problem.

 

Had a similar problem on my 72 bug. Wouldn't crank. Checked batt, starter, spark, everything checked out. Put on relay to bypass original ignition wiring and presto. Voltage drop could be affecting your ignition/spark set up. Battery may not put out voltage when cold, but checks out ok by the time you get to the store. CDI ignitions need proper voltage to function. Maybe keep your battery in the house, take it out early, install it and crank. If the problem stays the same it would indicate another component to focus on. If it fires up, then the battery is suffering from the cold, maybe a new one in order?

 

changed the coils and battery out with no avail but we did notice his bike turns over alot faster than mine so im wondering if it is the starter or voltage drop, of corse this is the day i leave my multimeter at work so ill bring it home tomorrow and see if voltage is dropping or if its maybe a starter issue