I have a 1997 Honda cbr600f3. Bike was sitting for years in a garage, 10,000 miles and in what I would say is good to fair condition, generally speaking.

At first could not get it running and there was gas pouring out of the air hoses that run to the carb. I took off the carb and tightend the carb boots put it back together and it started.
I idled it for about 15 mins turned it off. Several hours later I did the same thing again. Seemed fine except was running quite rough.
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Problem is that couple days later tried to start it and it backfired pretty loud and seems to be experiencing same issue and again there is also fuel in air hoses.
The petcock leaks but if I hook it to fuel hose quick it stops leaking once connected.

I took the air box off and one of the carbs has black residue in it all other looked good.
Idk what is causing this, any help?

 

I wouldn't expect a problem with the carb boots to solve a problem of fuel in the air lines.

I'm currently renovating a 1998 F3 that had been standing for a few years - less than yours. I had to remove the carbs but found that they were so badly corroded that the jets wouldn't come out. I eventually bought a second hand set of carbs and the bike is now running fine.

With the bike sitting as long as yours has been, I don't think you're going to get away without removing the carbs. Hopefully yours will clean up and not need replacing like mine did.

I hope it goes well for you.

 

Pulled new spark plugs and

 

No the pulling of the boots was actually unrelated to this matter, I pulled them because the two middle ones were missing a screw and were loose.
Also the carbs were taken off a couple months ago and replaced gaskets and some other things as well as cleaning them

 

A quick and easy check would be to put a good spark plug into each plug lead, earth it and turn the engine over to see if they're all sparking. That'll give you some confidence in your ignition.

Looks like a new set of plugs would be wise! Are they all like that?

 

Carbs and petcock needs complete disassembly for overhaul and restoration. Sitting causes petrol to dry up into plastic and clogs all sorts of tiny passages between jets and bleed holes in carb-venturi. Also messes up float-valves and they don’t seal. That’s problem here where float-bowl is filling up too high and petrol is backing up into air-passages inside carb and venturi. Leading to too rich mixtures. Liquid petrol dripping down into cylinders can also accumulate and hydro-lock engine.

Need to completely disassemble carb down to every last nut, bolt and individual component for scrubbing with PEA-based fuel-system cleaner. Spray “carb cleaner” no longer works due to removal of chlorinated compounds. Poke out all bleed holes in emulsion tubes and carb-venturi. Scrub out all secret hidden passages in carb body. It’s places you can’t see that hides worst clogs.

Then ultrasonic soak everything. Micro soda-blast everything for final cleaning. Replace all rubbers when re-assembling: petcock diaphragm, float valves, fuel-rail O-rings, pilot-screw O-rings, float bowl seals and even slide diaphragms if needed. Set float heights with wet-test confirmation. Balance carbs when installed. If you skip any of these steps, carbs won’t be fully factory-fresh clean and bike won’t run right. Thus, requiring yet another carb pull! Typically requires pulling carbs 5-6x for ever deeper cleaning before they’re back to factory-fresh OEM clean. One guy had to pull then 10x for deeper cleaning before it ran right!


Easiest and fastest way fix this is to send carbs+petcock to pros for expert restoration services. They have experience with repairing thousands of carbs with decades of experience. Reasonable fees and quick turnaround.

https://customcarbservices.com

 

Yes all the plugs are like that. And, wow thanks for the detailed response with thr photos as well! My only real question mark about the whole thing is why would it have started and ran for over an hour. Then couple days later not. Idk, maybe I will havr to take it somewhere to be re built just to do away with the headache of car rebuild

 

Clogs get worse over time.

Some of it is rust in tank from above fuel-level. Running bike shakes it loose. and it takes time to vibrate and work towards petcock. Takes some time to work their way through fuel-system to end where they pack together and back up flow even worse.

 

Oil dipstick smells like gasoline.

 

Yup, at least 2 failures for this to happen.

1. Petcock diaphragm broken and not sealing. This lets petrol flow to carbs even when engine isn’t spinning and generating vacuum to open petcock. Probably drips petrol through even when turned to OFF position.

2. float valves aren’t sealing and fuel-level gets too high and dribbles down into cylinders


DO NOT run engine until you get these fixed!!! Liquid petrol in cylinders does not compress! You stand good chance of hydrolocking engine and snapping con-rods and sending them out through side of block!