Ok, i'm at wits end. I've dotted i's and crossed t on this one. Maybe i've left something out on this one.
Pulled Carbs, cleaned, check and adjusted floats,replaced the intake boots to heads,replaced and re-routed fuel lines.Put it all back together. Cranked, over, not start. Pulled plugs, wet with gas, and a weak spark. It does have spark. I removed all the plugs, and cranked the engine over ,forcing all the fuel out of the cylinders.
Anyone have any ideas on what is wrong, Or what I should do or check next? I'm buying a 2nd set of new plugs to see if the engine comes to life.

Please help!!

 

Hey:

How new is the fuel as gas does not last long nowadays. Also the battery has to be at full charge or they have a weak spark. Plugs would be my first check as well. Sounds as if you're on the right track just make a change at a time till it fires up and be methodical not in a hurry or it will take longer than it should to get going. It is most likely carb related on these bikes, Good Luck.

Dub

 

Vacuum line to the petcock or the petcock itself

 

If your getting spark and fuel that's good.

How is the compression?

Also, you mentioned the plugs were out. Are the plug wires hooked up correctly? While sitting on the bike, the cylinders are numbered from left to right. The left side coil pack is left side to #1 and right side to #4 cylinder. The right coil pack is left side to #2 and right side to #3 cylinder.

In other words, sitting on the bike,
Coil packs 1-4 2-3
Cylinders 1-2-3-4

If the wires are correct and you have fuel and spark with good compression, I would check the cam timing next.

 

Doesn't this sound like the alternator damper? Replacing the alternator damper on your CBR1000F Honda motorcycle

 

Mate. Wet plugs means fuel is getting through. Is the spark weak at all plugs (from both coils is what I'm getting at)?

If it is, it could just be the battery. My appologies if you've already ruled this out but just because it cranks at a reasonable pace, doesn't mean there's enough for a spark. Have you tried a clutch start so that all the power goes to the plugs. Pull the light fuses so they don't sap power as soon as you turn the key too.

It just sounds like **** battery to me.

Press on, chill out with a cold beer and go back again. Fuel / air plus good spark at the right time = bang. You'll suss it out!

 

Thanks everyone! Charging the battery now, new plugs are due in today. Removed the suspected bad gas from the tank. Double checked spark with plugs in every ignition wire...All good. I'm hoping it is NOT the alternator. i will keep you posted. Thanks Again Everyone!!

 

we'll be waitin' for the lol

 

Update: New plugs installed and gaped at .030. Replaces suspected gas with 93 BP in a remote aux tank, being careful to block off the vac. line from carb for the petcock.Recharged battery, pulled the headlamp fuse and crancked engine. Full choke, no throttle.Not even trying to fire. Removed plugs, insert in coils and cranked over engin to check for spark on every cylinder.Got spark. HEY whats this... Gas coming out of #4 cylinder while cranking over.Looked inside top of piston, gas is in cylinder deep enough to cause aa ripple when the bike is bumped. Shut engine switch off, cranked engine over and placed a rag over cylinder to pump out gas from cylinder.

Removed air box, pulled carb's AGAIN, checked float and needle valve. Appears to be clean and shuts off the air supply while blowing air through the fuel line.

What is the proper float settings on a 1990 cbr1000f and where do you measure from so I make sure I have this correct. This bike will not get the best of me. I will win.....hehe. But it is driving me CRAZY!!!