Ok, so I know its been a long time but ive been out of town...I'm still here and supporting cbrforum 100%! anyway, I have gone through 3 petcocks looking for a good one..no luck. Whats happening is when I start my bike, gas pours out of my carb overflow tube...but the motor continues to run fine....which tells me that its the petcock that is leaking way too much fuel in....not the carbs themselves......aslo it pours out when on the bike...soemone told me a f3 one would work...it did not. Any after market ones or anyplace that I dont have to spend 190 bucks on one?

 

Im not 100% sure, but this sounds like a problem with the floats in the carbs, but i could be wrong. The only other thing i can think of is a vacuum problem with the petcock, but im no certified mechanic!

 

I am having petcock issues my self. I went to go order one for my 92 and was told by my dealer they couldn't get me one so I ordered one for a 95 F3 for $53.00.

In another thread very recently, someone advised me of this site for a gravity fed petcock, cost I think was $110.00

http://www.pingelonline.com/powerflo...ion_frames.htm

I'm with jakemc, providing all your lines are hooked up correctly, and your getting fuel discharge, I'd suspect the floats too.

 

hmm that seems decent...but wouldnt gravity fed still have the same problem i have now?.....because mine comes out without the vacuum hose hooked up......and its only supposted to let fuel out with the vacuum line hooked up and the motor running...so you should be able to take the tank off and turn the valve on and have nothing come out if im not mistaken

 

Yeah thats correct, you should be able to take the tank off without having a lot of gas come out, a little will though. There could be a problem with a diaphram in the petcock. Not sure if you have mentioned this before, but have you tried rebuilding the petcock? Have you had the carbs apart before?

 

I have taken the petcock apart and it does not seem to seal correctly..which im sure is why it is not working properlly...allthough I am not aware of any rebuild kits for them? And yes I thought it may be something with one of the float valves so I took them apart and cleaned them and tested them and they all sealed properlly and looked great...I took the bike out two or three times after that just to make sure the carbs were working properlly, everything seemed fine, then one day it just started pouring gas out the overflow tubes on the carbs. The only thing other than that that has been happening ever since i bought the bike is that sometimes when im at low rpms around 3 or so it feels very underpowered and the motor sounds like a v-twin......then at about 5 it goes back to normal and takes off like nobodies business...this doesnt happen all the time but it has more than once...so im guessing that its just letting way too much fuel from the tank and occasianally floods the motor a bit.

 

It's a definate, your petcock is shot. But in your first post you mentioned you went through three of them, were any of them brand new? Were any of them gravity fed or were they all vacuum types?

Ok, your getting fuel flow anyway, but too much it seems. Why?

You checked the Floats, none of them have sunk, they are all intact and you said they seated properly........

The floats go up and down obviously to let fuel in as needed and to shut fuel flow of when not needed through the fuel valve. Did you check the operation of the fuel valve? Gas has to get past it to fill the float bowls up enough to cause the fuel to spill out the overflow tube.

If it were me, this is where I'd begin my search to the problem. I'd make sure the integrity of the floats was ok, then I'd check to make sure the fuel valve stopped the fuel from entering the bowls when the floats were set to the proper level.

But how to test this on a Honda Carb? In the days when I messed with Datusn 510's, it was easy to do with the Weber Carbs, they had glass fronts on the float bowls, you could see the floats.

I can honestly say,I have never dicked around with the carbs on either of my F2's, but I would start my search in the float area making sure no rust or debris from a disentigrating diaphram was fouling the fuel valve and check all my o-rings.

I would then get a good manual that showed a cut out of the carbs and make sure I didn't over look something when I reassemled them. I'll attach one I found on the net, but it's not a very good scan.

It could be a bad o-ring inside the carb too I'd imagine. Actually, I'm not much help. Have you thought of just having your carbs rebuilt?

You have a problem and I think the petcock is just a sysmptom and not the disease. I think you havea carb issue. How long have you owned the bike? Did it sit for any period of time?

Sorry,I wish I could be of more help.

 

Hey, thanks for the input, I went to the honda dealership and talked to one of the mechanics. He said that regardless i need to replace the petcock, but also that it sounds like there is something wrong with the floats as well. I think you hit it dead on when you said that the petcock is a symptom, not the disease.....I will definatly pull the carbs apart and see whats going on in there, possibly order the new float valves and possibly the new floats themselves. I do not see replacement seats on royaners, is this critical to replace both the needle and the seat? Thanks again!

 

I doubt you need to replace the floats themselves. There really shouldn't be a reason for that. What you probably could replace are the needle and seat. The needle is the thing the float pushes up and the seat is what that fits into. if the needle is not fitting properly into the seat it will let fuel stream past and then to prevent gas from running directly into the engine and washing oil off the cylinders and contaminating the oil it flows out the overflow. Say your petcock leaks gas, the bike should still theoretically run because the floats/needles/seats will keep too much gas from filling the bowls. I suspect things would still leak a little out the overflow but I'm not certain.

I've worked on several different bikes, and whenever they leak out of the overflow, its pretty much always the needle and seat. Or such my experience has shown.

 

I just read Elmers diagnoses, and I have to agree with him. Concentrate on the needle, seat area. As for replacing the needle and the seat together, I would do it myself in all 4 carbs just for piece of mind. As to availablity of replacement seats, I have no clue. Nothing on royaners, thenI would ask a Dealers Parts Person if new ones can be purchased. If not, then go look on eBay and get some used carbs if they can be found cheap enough.

Would you mind posting the results once you get the problem solved? I am curious as to what it is. I'm not the mechanic I used to be, or thoughtI was,or should have been I guess.