CBR F3 wont start -help!

[Mforza]

Carbs nice and clean, plugs working fine, checked the electric, then put all back and still nothing! Will not start. Sometimes looks like it will start but then it just beckfires and nothing again. :?
I think the problem must be with airflow or something but I'm not sure.
Anybody have anything that I might have overlooked? :)
Thx

[Scored51]

Check the basics, especially if it ran before it was worked on. Make sure you have the plug wires on the right cylinders (1&4, 2&3), and the primary wires from the ignition box on the right coils (I believe the connectors are color coded). Also make sure all of the airbox plumbing is attached to the correct places.

Hope this helps.

[615HereICome]

Sounds really stupid but my problem one day is the side stand switch from when i put the farrings back on was not totally plugged in and did not allow my bike to start.

[marty]

-check your plugs, are they dry or covered in gas

-check to make sure carbs are getting gas (pull the drain in one of the bowls)

-try arcing the plug to a screw driver or the side of the block (you don't want to be holding the plug and the screwdriver at the same time :twisted: )

-and may be a bit redundant but make sure the kill switch and key are cut on. i have tried to push start my bikes countless times with the kill switch off, i usually just play it off to everyone who is watching as something more complicated and babble off something about the squish on the head or pipe resonance :lol:

[Mforza]

Do you think that the problem might be the 'air selenoid valve'? I think after all that it's not working. I'm not sure if that's needed to get the bike started. Should this valve work allways or just when the bike is moving?
Anybody knows anything about it?

[Dodd]

The only time my old F3 wouldn't start, it turned out the fuel pump stopped working (It was a 1998). I took it apart, cleaned up the electrical parts, put it back togeather and it ran fine for another 10K, and another 5k after it was bought by a friend of mine. Just an idea

[phildrummond]

The backfire means it's getting a spark and air, right? Just not the right amount of something, fuel + air + ignition.

Here's a super-basic one for ya. Have you tried a few drops of fresh fuel directly into each carb? Hardly the same engie but my old Yamaha 426 wouldn't start unless the fuel in the carb was like 5 minutes old. Yours sounds like a bigger problem, though. On the plugs, check the gaps, too. While they're out, soak them in gas in a plastic container. Metal container can react with the plugs and gas.

Keep in mind my knowledge is this: turn key, engine runs. Engine doesn't run, I call for help.

OK, back to my paper-pushing job where I can't cause much damage.

[dragos13]

Hey Martin, throw in a new fuel pump if you have one to rule that out of the problem. I dont think the valve is going to be an issue. If you need any help let me know, i have done work on F3's before :)

[Mforza]

I will try few more things on the weekend. If I will not get this thing running I will let you know Casey if you can halp me. Thx Martin

[dragos13]

For sure Martin, I think I might have a spare pump in the garage. Also have a spare motor too. Let me know and we can get her running this weekend!!!

[goldman812]

martin. are you sure the pilot jets on the carbs are clean??? that is first. then if you spray a little starting fluid in it and see if it starts. if it does, then u have a fuel issue. try to loosen the float bowl drain screw on the carbs to see if fuel is in the carbs? if no fuel in the carbs then check fuel pump,filters and fuel lines.if there is fuel in there, which could be if it is backfiring, then you probably have pilot jets plugged up in carbs or mixture screws plugged. usually if it is backfiring it is dirty carbs. if all that is done and still no go and u checked fuel pump, then move on to next area of electrical. could be firing at the wrong time. this is unlikly to be the problem, but if all else is fine, then check. is your leg all healed???

[Mforza]

The leg is fine, just a nice scar. Thanks for asking Craig.
The CBR is out of the house. I trade it for a classic bike. There was more problems with that bike and no time to work on it. After all it was a good trade. :D