i recently got a 99 600F4 and ran it for a few weeks with no problems. Now all of a sudden after it is warmed out and running for a few minutes the oil light comes on and she starts bogging down and dies. She starts back up fine after a few minutes and several tries. Changed oil and filter and same thing happens. fuel filter looks full. Has anyone had this happen? Can anyone give me a direction to go in? Thanks in advance..........

 

A little history on the bike would help. Could be as simple as the idle is adjusted too low and needs to be tweeked. What's the general overall condition of the bike ? Mileage, owners, recent maintenance.

 

i am 3rd owner. last owner is a friend and I know he did all the routine maintenance, oil & filter, air filter etc. Bike has about 15,000 miles on it and was not pampered thats for sure. this never happened to him before. unknown about any other maintenance. getting all ducks lined up to tear it down and check everything (fuel, air, ign) but just wondered if anyone had similiar experience.

 

check for a stopped up vent tube on the tank. Insects love finding round openings to build nests and crap in.

Sounds like you're starving the carbs, just like running out of gas. If the vent tube/s are blocked or capped off, you're building up a suction in the tank and potentially reducing the fuel flow through the petcock to the carbs. Once the motor stops, the carbs can fill up again as pressure slowly bleeds off. Then you go to crank up with full float bowls, and it takes a second or 3 for the carbs to re-prime and fire up. Then the process begins again.

 

yea there were remnants of a few spider webs under the tank. The air filter was clean, the vent tube was clear, all the hoses look good and the top of the carbs look good too. Next I guess will be testing the fuel pump, all the solenoids, carbs and plugs unless anyone has any other ideas. Thanks again

 

Hi. Have you filled up recently with fuel? If you have and the problem has just manifested itself, it's just possible that you have filled up at a garage that has had a crossover when it took a delivery of fuel. Sometimes the driver connects the diesel tank to the unleaded tank at the customers underground tank by mistake and there's your crossover! Take a sample and if you know how to check the specific gravity it should be around 0.745-0.750. Any higher and it may have diesel mixed with the unleaded which would cause the problem you are having.

 

ive got the 99 cbr too, and I'm having almost the same problem.
when i got it it ran great for awhile, then started having the problem

Itll start first crack, sometimes can ride it for a bit, then slowly starts to bogg down and dies.
If i choke it sometimes it fires right up and runs for a bit then it happens again, sometimes, it wont start at all for quite a while, unless it sits.
ive got a new fuel pump relay and fuel filter in and still does it.
I'm going to test the pump, but my gut tells me its electrical, which is brutal cuz i know nothing about electrical.
You have any luck let me know

 

Definitely check the vent on the tank. Is it usually warm where you are? Does it sit in the sun? If you think about it, bring a long flathead screwdriver with you and crack your float bowl drain screws next time it happens to see if fuel comes out.