I got a quick question for all you F3 gear heads out there. I just purchased a 97 F3 with around 20K miles on it. It ran like crap when I got it, but it still ran. I synced and cleaned the carbs and that night it ran like a dream. The next day I got about a mile away from home and it felt like it ran out of gas, then it would not start. After reading all the posts I could in here I came to the conclusion that the fuel pump went out on it.

It seems like a lot of people’s fuel pump goes out after they clean and sync their carbs. So is it a cause or just a correlation? Does the syncing exacerbate the fuel pump issue? I'm still not sure how these things work and all.

Is it mostly the pump that goes or the contacts? Is there a way to test?

Thanks in advanced everyone.

Cameron

 

I'd say it's neither Cause or Correlated. The bike is 12 years old, and the pump is not best in the world. The contacts seem to be the things that go out. Your bike probably most likely needed the carbs synch'd and cleaned. Now that the bike is running good and needs the fuel, the pump can't give it, maybe.

 

Thanks for the response Idodirt. I read your post on replacing the contacts. Good reading, is there a way to tell if its the pump or the contacts?

I took the hose running from the carbs to the fuel pump and plugged it directly into the gas tank. It runs now but as soon as I take off the choke it shuts off. Is this normal?

 

Taking the black endcap (1 screw) off the pump should give you and idea of the condition of the contacts. It's snug because there is an "O" ring around the base of the cap, and the wiring harness has a rubber gromet around it.


No, this is not normal. The bike should run fine without the pump except for possibly under heavy loads. How full is your tank ? Relying on gravity feed is subject to how full or empty the tank is. If you've just cleaned the carbs, it's possible that you've got the idle speed too low. Try turning it in a bit to see.

 

You could also check the vent from your tank to make sure it's not obstructed.

This could well be your problem, especially if it's still cutting out on you when you're bypassing the pump.

 

I pulled off the fuel pump and the contacts are definitely bad. They look really worn down and black/burnt. Looks as if i will have to replace them.
I don't think my idle screw is working. When I go to turn it, it feels as if everything turns (the tube and all). Should just the screw be turning? My idle was high last night and no matter which way I turn the screw, or how many times I turned it, it would not effect the idle.

Chuckbear thanks for the response. By tank vent do you mean the two hoses at the bottom of the tank? I don't think those are obstructed buy I will give it a look!

Thanks for all the help guys. I just put a new chain on last night and I can't wait to get my baby back on the road! The cage sure sucks

 

The idle screw tube and all does turn, that's normal. However it's not going to have an effect while the choke is applied. After you turn off your choke, that's when you can adjust your idle speed. You should feel resistance when turning the idle screw. If it turns freely, then you may have unscrewed it so much it fell out. I know the bike will not run very well, if at all, if the idle screw is unscrewed all the way out.

So how full was your tank ? Although your vent tubes might be clogged, I doubt that you would notice your engine dieing as quickly as you describe when turning off the choke. The amount of vaccuum generated in the tank as the fuel is drawn out while idling is miniscule. It wouldn't cause your bike to stall that quickly.

 

Sorry it took so long to get back. The tank is about 3/4 full. Is there any other reason the bike would be dying? I am so lost right now.

 

Well, before I started trying to find out why it's having troubles running, I'd get the fuel pump back in running condition. Then go from there. Are you going to go the contacts route, or replace the entire pump ?

 

Sorry it took me so long to get back but thanksgiving but a hold on the bike for now. I ordered new contacts, and thanks to your How-to, I was able to replace them. I also think I figured out my stalling problem also! Some how I managed to unscrew the idle cable from the carbs!!!!! Looks like I will have to take everything apart to put it back on?? Does anyone have a diagram on where the idle screw screws back into? I'm sure after some tinkering I will find where it goes.
Thanks again for all the quick responses everyone! After I get this all sorted out I will get back to you all to let you know how it goes.