Number two carburetor leaking fuel

[Fzjohn]

Hi guys, maybe you guys can help me. I have a problem with the number two carburetor leaking gas only when running. I have pulled the carburetors inspected the needles and jets cleaned them and replaced the float bowl gaskets. I turned the ignition to the arm position the fuel pump kicks on and pressurizes the carbs no leaks only when the motor is running it leaks

 

[Isleoman]

2005 Yamaha FZ1 (FZS1T) Carburetor

Shop online for OEM Carburetor parts that fit your 2005 Yamaha FZ1 (FZS1T), search all our OEM Parts or call at 877-999-5686

www.partshark.com

O-Ring Item 58 was what was leaking on my carbs a couple years ago. Looked like it was a carb bowl leak till I looked closer to see it was coming from higher up.

Those are on the fuel rail, Item 57 between carbs. If that's what it is, it requires de-racking the carbs. Don't panic, it's doable. If you find that's what it is report back and I''ll walk you thru it.

Personally, I won't clean 24 y.o. carbs without a complete de-rack and replacement of every o-ring. Getting the balance springs back in is a pain, but not hard when you know some tricks. There was a great FZ1OA thread on this with all the OEM and McMaster-Carr o-ring cross reference numbers.

 

[Isleoman]

Let me back up for a second. Is the gas leaking from around the outside of the #2 carb in which case my suggestion stands

or is it leaking from the hoses on the lower right side of the bike?If it's leaking from the hoses it's something internal like a stuck float

 

[Fzjohn]

Let me back up for a second. Is the gas leaking from around the outside of the #2 carb in which case my suggestion stands

or is it leaking from the hoses on the lower right side of the bike?If it's leaking from the hoses it's something internal like a stuck float

I'm not sure where its leaking from because I can only see it at the bottom of the float bowl and it's only happening when it's running on the bike

 

[Fzjohn]

2005 Yamaha FZ1 (FZS1T) Carburetor

Shop online for OEM Carburetor parts that fit your 2005 Yamaha FZ1 (FZS1T), search all our OEM Parts or call at 877-999-5686

www.partshark.com

O-Ring Item 58 was what was leaking on my carbs a couple years ago. Looked like it was a carb bowl leak till I looked closer to see it was coming from higher up.

Those are on the fuel rail, Item 57 between carbs. If that's what it is, it requires de-racking the carbs. Don't panic, it's doable. If you find that's what it is report back and I''ll walk you thru it.

Personally, I won't clean 24 y.o. carbs without a complete de-rack and replacement of every o-ring. Getting the balance springs back in is a pain, but not hard when you know some tricks. There was a great FZ1OA thread on this with all the OEM and McMaster-Carr o-ring cross reference numbers.

Would these O rings only leak when the engine's running because I could Turn the ignition on The fuel pump will run and pressurize the carbs but no leak but it will leak when the engine is running. I had the carbs rebuilt last year they never detached the carburetors to replace the old rings but I'm pretty sure they replaced the other rings this kind of makes sense to me.

 

[Deleted member 14062]

There was a great FZ1OA thread on this with all the OEM and McMaster-Carr o-ring cross reference numbers.

My biggest regret when the site went down was not having those mccmaster carr p/n's. I realize you have to buy a huge bag of them, but i wanted some for that fatefull day.

 

[Isleoman]

O-Rings?

New guy here, Big fixer upper!

So today after install I went to jump my bike and i got sparks and my starter turned over. The rubber cover of the starter relay came off and made contact with + jumper causing the starter too turn but i think in the wrong direction and blew the 30 amp fuse connected too it. I'm currently...

998cc.org

See the two .pdf files on page 2 of referenced thread. Thank Blue Flash.

The other FZ10a suggestion I forgot was turning the carbs upside down and pressurizing them with a hand pump to make sure the float valves are seating and not leaking before re-instal.

 

[Fzjohn]

Let me back up for a second. Is the gas leaking from around the outside of the #2 carb in which case my suggestion stands

or is it leaking from the hoses on the lower right side of the bike?If it's leaking from the hoses it's something internal like a stuck float

Its leaking from the carb

 

[cpabard]

http://[URL]https://www.partshark.com/oemparts/a/yam/500451e5f8700209bc79217e/carburetor

[/URL]

O-Ring Item 58 was what was leaking on my carbs a couple years ago. Looked like it was a carb bowl leak till I looked closer to see it was coming from higher up.

Those are on the fuel rail, Item 57 between carbs. If that's what it is, it requires de-racking the carbs. Don't panic, it's doable. If you find that's what it is report back and I''ll walk you thru it.

Personally, I won't clean 24 y.o. carbs without a complete de-rack and replacement of every o-ring. Getting the balance springs back in is a pain, but not hard when you know some tricks. There was a great FZ1OA thread on this with all the OEM and McMaster-Carr o-ring cross reference numbers.

I need to de-rack my 03 carbs and replace all the O-rings. I've overhauled carbs before, but have never done a de-rack. Any advice will be much appreciated. Thanks

 

[Isleoman]

https://www.partshark.com/oemparts/a/yam/5004451ef8700209bc78f5bf/carburetor

There’s only the two long screws (Item 52) that hold the four bodies together. The carbs will be easier to clean / soak as single units. Get four containers and keep all the parts from each body in its own container. It all comes apart simple enough.

The hard part is getting the three carb balance springs back into where they rest which is deep in between the bodies. Before you de-rack hold the carbs in front of you and visually find all three of the balance spring locations. Find them looking front to back and from the back looking towards the front. If you can get a picture of them in place take it.

The springs can't be inserted into their rest when fully extended. They need to be compressed. You can try to use something like hemostats or needle nose pliers to hold them closed but what happens is they compress the spring on only one side which is not the side your trying to get into the tight spot. The other issue with hemostats is if the spring slips out of them it’s going to tidily wink somewhere across your work area and be lost for good (ask me how I know). In fact if you have to order other stuff from Yamaha get a balance spring as insurance.

What I found worked for me was while the springs are out is to tie the springs with heavy duty thread on two sides so that the spring is compressed and then use a hemostat to grab them by the side and place them in their rest. Once in place you can take a thin exacto knife and cut the thread with the spring in place. Someone on FZ1OA came up with that method.

Cotton thread from a home sewing kit or your home sewing machine won’t be heavy / strong enough. I had some size “F” polyester thread for canvas / leather. The other thing that might work would be waxed dental floss or fishing line. If you can’t find a thread that works send me a PM with your address and I’ll send you a few feet in the mail. The other bitch here is tying a knot that won’t slip back open especially with fishing line. Using thin wire instead of thread to tie the springs closed would solve the knot issue but you need to be able to cut it once in place.

An FZ1OA member posted that he was able to loosen the two long screws just enough to allow the carb bodies to be pulled just slightly apart while still being captured by the long screws. While the bodies are loose he was able to take each of the fuel logs Item 57 and slide them side ways enough to remove/replace the orings. I assume he did the same thing with item 68. I didn’t try this method because I wanted to do the full Monty clean of each carb body. If the balance springs have you concerned you can give it a try. I’m a little skeptical that you can slide the carbs side ways enough to get the logs out.

I have to resign myself to the fact that carb cleaning takes time when done right.

You could also count the number of turns to full tight on the three balance screw adjusters. Then when you re-assemble you can get the screw adjusters in the ball park to get it started before using vacuum gages.

 

[cpabard]

Many thanks for all the great info, Isleoman.

I didn't have anything stronger than dental floss and, as you warned, the synch spring easily broke it. But I can see how the heavy thread approach would work well. After many failed attempts, I got the three synch springs installed using industrial/medical tweezers and a long, straight pick (plus a bit of praying and cussing). If I ever have to do this again, it will be with the heavy thread and spare springs (dental floss tape, which is wide and strong might work, too).

After separating the carbs and replacing the O-rings, I used the two long bolts and carb spacers to keep the carbs loosely together during reassembly. For carbs 1-3, I was able to install the spring in the keeper over the raised teet, then slide the adjacent carb over until the tang butted against the spring. Using the tweezers to keep the spring in place, I used the straight pick to compress the spring and then seat the carbs together by pushing the carbs together while slipping the tang between the adjusting screw and spring. For some reason, this would not work on the 3 to 4 carbs, so I had make many attempts to compress the spring and force it into its place while the 3 and 4 carbs were seated with the tang under the adjusting screw. I did send the spring flying several times, but got lucky and found it.

 

[Isleoman]

You work fast, congrats on getting it done. I still haven’t come across the spring I lost it’s been more than a year.

What do you think about my last comment concerning loosening the bodies and sliding the fuel logs out. Do you think there’s enough room?

 

[cpabard]

It sounds feasible, but it never crossed my mind to try that. (I was pretty far into it by the time I saw your post.) It sure would make the job a lot easier. One wonders how they were assembled at the factory. Surely they had a trick for it. I can picture a row of techs putting them together and springs flying everywhere.

Perhaps springs are like socks in the dryer...sometimes they find a better place to be.