Petcock not working? Fuel not getting to the carbs and didn't know on the older bikes it's a petcock that spits fuel to go? Well When ordering the part it's called the "cover set" for the F2, and it's the whole petcock with an F3. It's very likely you can purchase just the cover set from an F2 and it will match the F3 since they are the exact same parts and this was not changed in the year transition.

BikeBandit and most places can order this part for you and it comes in the normal catalog too. The main assembly is not a part that breaks easily, the "cover set" (that's the name for the part you need to replace) (BB part# 1649093) on the side that has the diaphragms/disc/springs and does break or comes loose inside. Usually it's the plastic disc that comes off and blocks all fuel. It didn't just come off either, the diaphragm is likely worn and just popping it back on will not fix it. So if it starts messin up, just replace it or get an AMA membership so you've got free motorcycle towing. (AMA also gets discount at Bike Bandit! Sorry not promotin em just a pleased member).

What goes wrong?
So when this plastic disc pops off, the diaphragm itself usually is worn. If you look closely at the nipple the plastic disc connects to you may see some wire mesh. What will be more apparent is the distortion of the diaphragm. Without a new one it's hard to compare against but if it's shot then it cannot sit flat in the cover brim. It will look distorted/warped when you set it in there especially with the plastic disc connected. Attached is a pic that kinda shows this called "Why failed".

This is sure sign it's gone and you'll need to replace it even if you can get 1-800 miles out of this just by popping it back on. Colder states will probably get you further with that then say AZ where I live but it's still inevitable. Next time you'll probably be in the middle of nowhere in a flash blizzard just cuz that's how it works (remember I'm in AZ).
The reason it failed is because it sits, harsh fuels/additives/ AND just plain ol, operation especially under heavy load engine vacuum drives this part so the higher RPMS the harder this piece gets sucked on and the faster it moves. Guys could only dream.

I plan to keep my old one on hand just so I have it in my lil tool box on the battery for that flash blizzard day when the new one brakes. This way I can hopefully get that 1-800 miles to get my *** home esp with only 4 phillips to get to it.

Rebuild/Replace:

-So to rebuild this thing you just unscrew the 4 screws from the main valve on the side. They're the only 4 screws you can get to. CAREFULLY unscrew the last screw and prep to catch the spring that will drop from inside. Worst case you're fishing it from above the starter.

-Next assemble the new pieces just like what you have now. The big nipples on the large and small conical diaphragms is what connects inside the metal ring/(necklace bead lookin thing). You press hard with your thumb in the center of the nipple on the backside while the nipple is being forced into the hole. You then rotate the diaphragm and ring around back and forth until the nipple seats inside.

-Slip the large diaphragm thru the cover set with the huge hole in it so the indentions for the diaphragm edges match correctly.

-Put the spring inside the main valve of the petcock and then reach in and put the assembled piece, breather tube connector facing forward, all in place and hold it there so you can put a screw in. Once 1 screw is in the spring will stay in place. Until then figure out how to balance all three parts and you'll get it.

-There's an attached pic of the assembled item out of the bike.

-You're done and you only needed a phillips screw driver for a drive or no drive issue! This is like the only part that you can get away with that on I think....

-P.S. I hope you turned off your fuel valve before performing this. If not then enjoy the smell.


HOW DO I KEEP THIS FROM HAPPENING AGAIN!?!?!?!?!
As I understand the suction only occurs while the petcock is in normal operation which is when the petcock uses engine vacuum to force deliver fuel. You then go to reserve (which is like 1/3 your tank) and all still continues to operate just fine especially because you have float bowls in the carbs and fuel in the lines which acts as a small reserve as is... The ONLY difference that I know of here is that fuel is no longer forcefully delivered via engine vacuum, only gravity and with plenty of space to fill there's usually plenty of fuel available.
So my theory which I will test out will be to leave it on Reserve forever! I can't imagine this being an issue except while at the track and I accidentally ran the track the whole time last time on reserve with no issues. So I think this will be ok. If theory is correct, the diaphragm will never undergo stress causing the disc to become disconnected which is what blocks the fuel, otherwise reserve would also work. So the diphragm should never fail, and barring me being a bad *** motoGP racer (I'm not) I think fuel delivery will always be ok.

Cover Set Bike Bandit Part# 1649093 for Honda CBR F2. I have an F3 as well and the petcock is the exact same however the available parts are different F2 vs. F3 when ordering. I personally have not unbolted the F3 petcock and bolted it to the F2 tank, but they are a 100% match externally and inside the fuel tank so it should be the same assembly as they only changed a few things for the F2 to F3 mainly suspension and nothing fuel delivery related. I've even used the cams from the F3 in my F2 with 20k so pretty damn sure the petcock is interchangable. This also means purchasing the F2 part will be cheaper than the F3 part since you buy a piece not the whole assembly.

 

WELL that didn't work. Damn thing popped off as usual. At least I only ever have to push it 1/4 mile home when this happens since it seems to happen at home when it does and I only have 1/4 mile of fuel in the carbs....

EITHER WAY... I think I really do have it fixed now. Below is my latest post covering how to fix it with a pic of the mod done.

https://cbrforum.com/forum/f2-tech-9...al-fix-153411/