Need help CBR starting problem
 

Hello Everyone I have a 1991 CBR 1000f with 9k on the clock it runs super once its started but getting it started when its cold & the fuel tank is below half a tankis the problem ...if I choke it when the tank is full it will run for about 5 minutes then stall, I shut off the choke & restart it &it will run fine but if there is less then half a tank of fuel in it I am screwed I have to make a trip to the gas station with a gas can.. any ideas what this could be maybe fuel filter?
thank you in advance for your help :)

RE: Need help CBR starting problem
 

trade in for 08 busa

RE: Need help CBR starting problem
 

did you try turning your petcock to reserve?

RE: Need help CBR starting problem
 

My bike (1990 F L) also stalls when I run it on the choke for that long. Try going to half choke as soon as you can,,,,The "half tank of gas" worries me though - your bike has a vacuum release fuel flow in the tap unit - sounds like either the filter's blocked or the diaphragm's a bit past it...you may also have a partial blockage in the vacuum tube betwee carbs 2 and 3...when the choke's on it takes more vacuum because it's pulling more fuel........?
That's the best I can do without seeing the beast.

RE: Need help CBR starting problem
 

Thank you to everyone that helped I guess i'll have to wait till the weather gets a little warmer to tinker with it or make sure the gas tank is always full :)
here is a link to her getting down on youtube if you would like to check her out.

http://www.youtube.com/watch?v=YxHLs7-EV-o

RE: Need help CBR starting problem
 

If you run the bike and a blockage is causing the bike to run 'lean", you run the risk of burning your valves.....The check is quick, and simple : remove the tank (2 bolts in front, one at rear, plus 3 hoses (one is vacuum) and you're nearly there. Pull the vacuum hose off, and check it's sound. Drain the tank, remove the tap carefully, and check for muck in the filters.....even if you have to remove the carbs, it's not a major job - let us know and we'll take you through it......removal, clean and refit carbs can be done in about 1 1/2 hours complete. You can of course take a shortcut and suck on the vacuum hose with it connected to the tank, but petrol in your mouth is nasty.......[8D]

RE: Need help CBR starting problem
 

I agree with Shadow1. In that clip the bike is running on what is in the line and sucks some out of the bowls then falls on its face.

To verify it you can pull the hose off at the petcock and put a vacuum on thesmaller line. You should have good fuel flow, if you don't pull the petcock and clean it.

When doing my carbs adjustments I use a vacuum pump that is for sucking break fluid. I keep a vacuum on the petcock to keep the bike running instead of using a "T". You can also use a long line hooked to another vehicle.

RE: Need help CBR starting problem
 

Yea your right I dont want to burn a valve. I'll check it this weekend & let you know..its funny I work on cars all the time & can figure them out but this is my baby & I get nervouse when I start pulling it apart, halfway through I am like the hell with this! I am gonna screw something up & wont be able to go riding this weekend so hurry up &I put it back together ;)

RE: Need help CBR starting problem
 

What happens if you run it, full tank, with the fuel cap open?

RE: Need help CBR starting problem
 

You'll get gas, all over you "multiplication machinery" and it burns like hell !! he he:)
I think I see what you're getting at, perhaps some sort of vent blockage in the tank ? Maybe vent hose blocked ? Good thinking....!