Carbs leak while fuel is on

[Jaytibba]

New bike I've been restoring. Just took carbs apart and cleaned. 17mm float height on both of them. Nothing looked wrong they looked good but when I installed and tried to start the bike they were leaking a good amount of fuel out of them. Bike did not start, guessing it was flooded.

Ugh just want to ride this thing. One thing is that the bike did fall on its side today on the grass while installing new front forks.. pet cock does let out a very small flow of gas when the tank is off the bike but in the on position but not much at all

[jkv45]

Did you replace the Float Valves (aka - "needle and seat") ?

That's what shuts off the fuel to the floatbowls when the level is correct. They wear and eventually don't seal.

Rust from the tank can also hold the valves open if you don't have an adequate in-line fuel filter.

[Ghostt]

Okay two problems need to be addressed.

One: float valves, did you replace them? Fuel bowls O-rings? Check the needle seats?

Two: did the fuel stop flowing once the bike was off? Did this happen while it was off? If so your petcock is shot, replace it.

If your petcock is shot, save your time, and money and get a new one, the cost of rebuilding it isn't much cheaper, due to you need two separate kits, as they for some reason don't make just one.

New one cost about $65.00

1988~00 models
http://www.partzilla.com/parts/detai...1023-1139.html

2001~07 models
http://www.partzilla.com/parts/detai...1023-1393.html



Also be sure to order the orings(92022-183 WASHER,6.2X11X1.5)and new bolts(92001-1091BOLT,6X20),trust me you'll be better off in the long run.

Rebuilding kits are about $60 total.

K&L Supply Diaphragm Only for Fuel Petcock Repair Kit 18-6638 https://www.amazon.com/dp/B0055DWO60..._s1CGub1W9N3PH

K&L Supply Fuel Petcock Repair Kit 18-2723 https://www.amazon.com/dp/B001KO2JRW..._U1CGub05DT5NT

http://faq.ninja250.org/wiki/Rebuild...tcock/fuel_tap

IMHO not worth it rebuilding, also be sure to check vacuum and fuel lines for wear, holes, and cracks, if in doubt replace them. Also replace the two small O-rings on the bolts for the petcock part# 92022.

This is the time to add an inline filter filter, if you don't have one already.

K&N 81-0221 Fuel Filter https://www.amazon.com/dp/B000E2AR70..._ncMwwbE333H0E






Your messing with gasoline, not a time to be cheap, or shortcuts. The risk is too high!!!

[Jaytibba]

I messed up then. I wanted to drain the gas out to put new has in. Turned the Petcock on and nothing happened. So I took it apart and cleaned it, now it's bad I guess :/
Yes, the fuel would still flow out of the carbs without trying to start it or anything

Is there some type of kit I can buy for a 1993 250 that has all of those things in it. I may need to to do some research because I'm not sure exactly what I'm looking for with carb parts

Inline fuel filter was installed today, along with new fittings and fuel lines.

Would you say the bike not starting was due to this carb issue?

[Lazarus]

K&L supply has a carb rebuild kits I believe. I always order my rebuild kits from Murphys at least I'm pretty sure that's the name. Google it, should come up right away.

Carbs leaking gas will cause a no start. It happened to me (made a thread about it) turns out my petcock was leaking and flooding my engine. That and some dirty float needle seats. I mean I had the carbs off the bike anyways why not clean them again.

[Jaytibba]

Awesome, I think I found what I need. Is there supposed to be a hose connected to the "vent" tube? The one next to wher the gas comes out. And the base of the tank hose just kinda sits there and dosent connect to anything right?

[Ghostt]

It's not supposed to, it's a vent/drain hose for the tank, carburetor has its own tube, but not necessary, except to keep fuel off the hot engine.


Also you didn't read my post above about the petcock, read it again.

[juliusmichaelhonrada]

Originally Posted by Jaytibba

Awesome, I think I found what I need. Is there supposed to be a hose connected to the "vent" tube? The one next to wher the gas comes out. And the base of the tank hose just kinda sits there and dosent connect to anything right?

The one next to the gas outlet is a vacuum outlet , you put a hose there and connect it to the carb vacuum line in the engine side of the carb there is a nipple per carburetor one goes to the coasting enrichener and one goes to the petcock .

[Ghostt]

My bad, never reply when your tired, I thought you mentioned the nipple on the back of the tank itself, I need coffee.

Try looking here

http://faq.ninja250.org/wiki/Carburetor_photos

[Jaytibba]

I did find these
http://www.partzilla.com/parts/detai...P-4097365.html

I did also find the Petcock on the same site. Ready to order both of needed

But it seems like if I don't have a vaccume hose going from the petcock to the carb, won't that itself cause an issue? What if that vaccume line just isn't telling the fuel to stop pumping or something.

EDIT: found vaccume hose to Petcock and installed it. With bike off but Petcock on gas still leaks. Looks like Petcock and carb rebuild it is

[Ghostt]

The petcock needs a vacuum to function properly in order for fuel to flow, no vacuum, no flow. It's a safety feature, if the bike is off, no fuel should flow, in case the float valves are not working properly.

If the vacuum line was off the petcock nipple, and fuel still flowed, your petcock has issues/bad. Also with an open vacuum post, the bike will not run properly.

But if the float valves were working properly, once the bowls are full, the valves shut the flow of fuel off, so you need to address those before you do anything else.

I'd also recommend checking the oil, odds are you have gas in the oil now, so once you get the carburetors and petcock fixed change the oil and filter as well.

Gas and oil don't mix well for the engine.

SIDENOTE: send @ducatiman a PM he has rebuilding kits, for a lot cheaper than you'll find anywhere, and he also offers a full carburetor services.

[Jaytibba]

Thanks for the info, learning a lot here so far you guys are great! Looks like I will be buying a brand new Petcock. I also just sent a message to Ducatiman about his kit.

[Ghostt]

I have know Ducatiman for a long time, we meet over at EX-500.com about 8 years ago. He's well known over there for his excellent services and reasonable prices as well.

When I joined this forum, I told him about it, and now he's been here doing the same. He's the only one I would trust with my carburetors, and I have. He has the tools, and experience to deliver a top quality products, and services.

Too many threads here, as well as other forums about carburetors, and a lot of wasted time, money, and aggravation. When just admitting your in too deep, and paying someone else to do the job correctly the first time.

I have first hand experience with a set of his carburetors. They arrived all fresh and refurbished, installed then, prime the carburetors, and started on the first time, no issues, no drama, just set the idle, and off I went.

Here's the thread on a little experiment Ducatiman and I are doing now.
https://www.ninjette.org/forums/showthread.php?t=269055

Here is a link to his services, parts, etc...
https://www.ninjette.org/forums/showthread.php?t=226815

And he's another link from fellow forum members feedback on his services.
https://www.ninjette.org/forums/showthread.php?t=239678


Carburetors are not as easy as they seem, especially if they've been sitting awhile, and/or messed with by previous owners.



Beyond common problems...... comprehensive carb cleaning is not for everyone, there is much to go wrong in short order. We've seen many members endlessly chase their tails, break stuff, assemble and adjust stuff wrong.

With some of the fleet becoming old, the vast majority require much more than "cleaning". The potential for leakage must be addressed, any less attention is irresponsible, and yes, this may even require thowing money and parts at them (gasp). Consumables...carb innards are not forever items.

And certainly there is MORE... much more....to it than simply addressing the pilot jets while they are out and on the bench.

Please...you're screwing around with FUEL...if not absolutely sure of what you're doing...send them to someone who is.

[Spencerrides]

Sounds like sticking float needles/valve clean and LUBRICATE the float needle/valve and valve hole to eliminate sticking.

And OP replace O-rings, replace float needles if needed, I only read a few sentences of this post so I'm just throwing out suggestions.



If I'm incorrect these guys should help you their great.
@Jaytibba @Ghostt

[Ghostt]

Lubricant with what?

[Spencerrides]

I used vasoline/protroleum jelly worked well for me @Ghostt did you see my question

[Jaytibba]

I cleaned the **** out of needles and holes today.
Float height is fine. The needles look brand new.
If I blow of the fuel inlet then press on the floats the air will stop / clog
But when I run fuel into the carb it won't seat..
I would hate to replace the needles because they look fine, but **** idk what else it could be.

[RacinNinja]

Originally Posted by Jaytibba

I cleaned the **** out of needles and holes today.
Float height is fine. The needles look brand new.
If I blow of the fuel inlet then press on the floats the air will stop / clog
But when I run fuel into the carb it won't seat..
I would hate to replace the needles because they look fine, but **** idk what else it could be.

Looks mean absolutely nothing.

If the parts don't work, the parts don't work.

Needles should seal WITHOUT pressing on the floats with the carbs upside down. If they don't, replace them.

[Jaytibba]

Problem solved. Kinda ghetto but I ended up just messing with the wire that holds the float needle onto the float. Kinda changed it a bit, then readjusted my float height. No more leak yay. Now onto water pump leaking and a couple more things and this thing should be revived from the dead

[Ghostt]

[Ghostt]

Originally Posted by Spencerrides

I used vasoline/protroleum jelly worked well for me @Ghostt did you see my question

Gasoline breaks down petroleum jelly, so that's out.

If the valve is sticking there's a reason for it. Float valves are a consumable part, due to the viton tip, and the little spring loaded pin. Just like O-rings, bowl gaskets, etc....

Rigging them is ill advised to say the least, this is a major safety issue, fire, burning, engine damage, etc...

You have been forewarned.

[Jaytibba]

Your absolutely right.. Well atleast now I can start the bike and fix other issues but I will replace the needles with new ones before it is actually ridden.

Only things is needs now is new water pump. It has a leak and I've read that pretty much of its leaking out of that little hole then it needs to be replaced. So a newer used one will be ordered.

Just noticed choke on carb is stuck.. Ugh sick of taking that carb off!

Other than that a new battery and fluids should be it

Valves have been adjusted. New plugs and air filter. Carbs cleaned. New front and rear suspension from newer years. Inline fuel filter, and new front end (street fighter style).

I know I bit more then I can chew but I do have some experience and I'm learning so much that I believe the experience alone is worth it and will help me with all the bikes I may own in the future. And of course I have you guys (:

[Spencerrides]

Originally Posted by Ghostt

Gasoline breaks down petroleum jelly, so that's out.

If the valve is sticking there's a reason for it. Float valves are a consumable part, due to the viton tip, and the little spring loaded pin. Just like O-rings, bowl gaskets, etc....

Rigging them is ill advised to say the least, this is a major safety issue, fire, burning, engine damage, etc...

You have been forewarned.

I used protroleum jelly so I'm sure the gasoline has broke down the jelly I used by now


BUT @Ghostt my Petcock rubber vent hole is leaking gasoline any idea how to fix it?

[Lazarus]

Man I missed all the fun. The experience from working on your own bike translates to a lot of other areas in life, its good you are learning/have previous expierince.

As ghost said, rigging anything on the bike is very unsafe and the issue should be addressed properly. Not sure if it was mentioned or not but check the carb bowl gaskets (There are 2). They can become flat and distorted causing leaks. Might be a good idea to replace all 8 carb bowl screws as well. Should the screws be cross threaded/old/stripped take your pick, the carb bowls won't press the gaskets/bowls up enough to stop gas from flowing.
That combined with the bad petcock/bad float needles/seats would cause a problem. Definitely change your oil a couple times as was mentioned.

Alright, now that slowbro has caught up, hope this info helps. My apologies if I said something that has already been written.

[Ghostt]

Originally Posted by Spencerrides

I used protroleum jelly so I'm sure the gasoline has broke down the jelly I used by now


BUT @Ghostt my Petcock rubber vent hole is leaking gasoline any idea how to fix it?

Do you mean it's leaking gas thru the vacuum port? Or the back ?

Testing a petcock is easy, but it suck literally. Bike is off, fuel line off the carburetors, going to a clear bottle, water bottle works great for this part.

If at this point fuel is coming out the petcock, in any setting besides PRI, then it's bad, replace.

SIDENOTE: PreGen has off, run, res, and requires vacuum for both. NewGen has off, run, and pri, the pri, or prime bypasses the vacuum part and allows you to prime the carburetors, saving you from endless cranking, etc.....

It didn't leak,
With the petcock off, attach one end of a vacuum to the petcock, and the other end to your mouth, and start sucking, if at this point you get gas in your mouth, petcock is bad, replace.

While applying vacuum did any fuel flow into the bottle? There shouldn't be any fuel in the bottle, petcock is off, if there is fuel, petcock bad, replace.

If the off position passed, go the run, and res(PreGen only) repeat the vacuum test, when vacuum is applied fuel should flow freely, note how much fuel, if it's barely coming out, there's an issue right there, replace the petcock.

You can confirm any findings by doing an R.D.I. on said petcock.

I know a lot people say rebuild the petcock, but it's not cheaper as I stated in my write-up, plus your getting a whole petcock, New inlet screens, seals etc...

I went the rebuilding route before I did some research, and wasn't happy because for a few dollars more I could have had the whole piece, and saved my time

Something to consider when weighing the facts, and figures don't forget to factor in time, and aggravation as well.

Could also be the gasket on the petcock to the tank is bad? Or the two O-rings around the bolts leaking?

I had one so bad one time it was letting fuel thru and was sucking it into the carburetor vacuum post, causing too much gas to the cylinder.

As I said in my petcock write-up your better off in the long run just to order a new one.

[Alex]

Is it up and running?

[Jaytibba]

yep its up and running. I still have some things I would like to do, but it runs and drives well.
little smoke coming from the exhaust flanges so its most likely just burning off oil and crap thats caught in there. My newer water pump also leaks a tad bit from the peep hole but she idles nice and runs fine revs right up and has good power. Here is a crappy picture of her current state.



The fairings were all super messed up so thats why I decided to go the naked route. It looks much better in person but yeah im happy with it for what iv'e spent

[Triple Jim]

If you do need a grease that's made for lubricating parts in a fuel system, EZ Turn works well. You can get it from places like Aircraft Spruce.

Here's a post on the triples board I wrote about it a while back:

http://kawi2strokes.com/forum/viewtopic.php?f=25&t=3592

[Jaytibba]

Just cleaned her up. Added air to tires and topped of the oil. The water pump is no longer leaking I guess it just needed to purge a little water. May need to tighten suspension but I took her out last night and she ran and drove good!

[CaliGrrl]

Whoo!!! Back on the roads!