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It's not the float/needle - but gas is still leaking from hose. HELP

Started by aslovik, August 19, 2013, 10:16:38 AM

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aslovik


I took apart the carbs on my FJ1200 and gave them a thorough cleaning. Now, it turns over easily and sounds better than it has in years.

One problem though -it streams gas from one of the hoses. Not one of the hoses connected to the bowls, but one of the other two longer and thicker hoses that are connected to the carbs.

What are those two hoses? Any idea why one would be leaking gas? Any help or suggestions would be GREATLY appreciated!

Adam

Pat Conlon

Those hoses are the vent hoses for your float bowls. The fuel in the bowls needs to stay at atmospheric pressure to assure proper flow in the carbs.

Gas flowing out of the vent hoses usually indicates that, 1) the float level is set too high or 2) that the float is sticking open or 3)something is preventing the float needle from fully seating or, 4) your float needle seat O rings are leaking.

If you took apart your carbs for cleaning (good for you) you need to be sure you replace those float needle seat o rings with new ones..

My bet is on #4 above..

Report back on what you find....

Here is some good reading: http://www.fjowners.com/index.php?topic=46.0
1) Free Owners Manual download: https://tinyurl.com/fmsz7hk9
2) Don't store your FJ with E10 fuel https://tinyurl.com/3cjrfct5
3) Replace your old stock rubber brake lines.
4) Important items for the '84-87 FJ's:
Safety wire: https://tinyurl.com/99zp8ufh
Fuel line: https://tinyurl.com/bdff9bf3

FJmonkey

Quote from: Pat Conlon on August 19, 2013, 11:30:59 AM
My bet is on #4


Pat, that is amazing, you are predicting that carb #4 is the one leaking???? His post did not even say what side is leaking....  :biggrin:

I just had to post that, it was the first though I had when I read that line....
The glass is not half full, it was engineered with a 2X safety factor.

'86 Ambulance - Bent frame, cracked case, due for an overhaul
'89 Stormy Blue - Suits my Dark Side

aslovik

Quote from: Pat Conlon on August 19, 2013, 11:30:59 AM
Those hoses are the vent hoses for your float bowls. The fuel in the bowls needs to stay at atmospheric pressure to assure proper flow in the carbs.

Gas flowing out of the vent hoses usually indicates that, 1) the float level is set too high or 2) that the float is sticking open or 3)something is preventing the float needle from fully seating or, 4) your float needle seat O rings are leaking.

If you took apart your carbs for cleaning (good for you) you need to be sure you replace those float needle seat o rings with new ones..

My bet is on #4

Report back on what you find....

Thanks for the reply. The thought of having to take the carbs out and apart again is depressing me....

I thought that if the float was stuck open, one of the hoses connected to the bowls would leak gas - that is what was happening that caused me to clean the carbs in the first place but no longer happening. Does that eliminate #2?

I'd hate to replace to o-rings and find out it is something else. Is there anything else I can/need to check while I am there? (how do I check float level?). Is the only way to find out if the o-ring is leaking is to replace it and see if it fixes the problem?

Thanks again for all the advice. I'll report back what I find.

Adam




Pat Conlon

That is one reason I ditched the oem air box and installed Unipods...it makes carb removal much, much, much easier.

Yes, if the carbs are clean, I would think #2 and #3 would be ok.. Over time those float needle seat O rings dry out and allow gas to leak thru.

Go ahead and double check your float settings...but I really think it's the o rings. 
1) Free Owners Manual download: https://tinyurl.com/fmsz7hk9
2) Don't store your FJ with E10 fuel https://tinyurl.com/3cjrfct5
3) Replace your old stock rubber brake lines.
4) Important items for the '84-87 FJ's:
Safety wire: https://tinyurl.com/99zp8ufh
Fuel line: https://tinyurl.com/bdff9bf3

FJmonkey

You can perform a simple float height check with some clear tubing. On the center stand, shove one end onto the bowl drain and hold the other end so it is higher than the bowl. Crack open the drain screw and see where the fuel sits. Then check the others to see if they sit higher/lower than the others. The other way is to drain them, pull the carb bowls off and measure the height setting on each float. Use the search function, we have had some recent discussion on this so it should be easy to find.
The glass is not half full, it was engineered with a 2X safety factor.

'86 Ambulance - Bent frame, cracked case, due for an overhaul
'89 Stormy Blue - Suits my Dark Side

aslovik

Quote from: Pat Conlon on August 19, 2013, 12:03:27 PM
That is one reason I ditched the oem air box and installed Unipods...it makes carb removal much, much, much easier.

Yes, if the carbs are clean, I would think #2 and #3 would be ok.. Over time those float needle seat O rings dry out and allow gas to leak thru.

Go ahead and double check your float settings...but I really think it's the o rings. 

I can't thank you enough for taking the time. Is this the o-ring you are talking about? (I just want to be sure)


http://awesomescreenshot.com/03f1mh2r71

Adam

Pat Conlon

Yeppers.
I would go ahead and order the full kit from RPM, including the ss replacement screws.
Those soft oem Phillips screws suck.

If you're short of funds, just the o rings for now..

Mark ( FJ Monkey) brought up a very good point about checking your 'fuel level'.
Do that first. Maybe one float got misadjusted and just needs readjustment.

My money is still on the o rings.
1) Free Owners Manual download: https://tinyurl.com/fmsz7hk9
2) Don't store your FJ with E10 fuel https://tinyurl.com/3cjrfct5
3) Replace your old stock rubber brake lines.
4) Important items for the '84-87 FJ's:
Safety wire: https://tinyurl.com/99zp8ufh
Fuel line: https://tinyurl.com/bdff9bf3

FJmonkey

Quote from: aslovik on August 19, 2013, 12:16:51 PM
I can't thank you enough for taking the time. Is this the o-ring you are talking about? (I just want to be sure)
http://awesomescreenshot.com/03f1mh2r71

Adam

Yes, that is the one. When I replaced mine I was shocked at how bad they looked and that they were not leaking.
The glass is not half full, it was engineered with a 2X safety factor.

'86 Ambulance - Bent frame, cracked case, due for an overhaul
'89 Stormy Blue - Suits my Dark Side

aslovik

Quote from: Pat Conlon on August 19, 2013, 12:32:50 PM
Yeppers.
I would go ahead and order the full kit from RPM, including the ss replacement screws.
Those soft oem Phillips screws suck.

If you're short of funds, just the o rings for now..

Mark ( FJ Monkey) brought up a very good point about checking your 'fuel level'.
Do that first. Maybe one float got misadjusted and just needs readjustment.

My money is still on the o rings.


Last questions (I hope): If I order these unipods, I then don't need the airbox at all - is that right? I just replace the air box with these? Anything that will make getting the carbs out and in easier is worth the money.


Pat Conlon

Yep, they replace the air box. You also need to order the vent filter that goes on your crankcase breather tube.
Also, put on a longer crankcase vent hose. About 8 to 10 inches long...this will help the hot oil mist cool down and condense in the longer hose and drain back to the crankcase.
Review the posts on Unipods for advise on shimming the jet needles so as to prevent lean running in the upper RPMs.
Might as well replace those stock 37.5 pilot jets with slightly richer 40 pilot jets while you at it...
1) Free Owners Manual download: https://tinyurl.com/fmsz7hk9
2) Don't store your FJ with E10 fuel https://tinyurl.com/3cjrfct5
3) Replace your old stock rubber brake lines.
4) Important items for the '84-87 FJ's:
Safety wire: https://tinyurl.com/99zp8ufh
Fuel line: https://tinyurl.com/bdff9bf3

aslovik

I visually inspected the o rings and they appear like new (not surprising since the bike only has ~9k miles on it). The height of the floats also looks to be the same as the others. I noticed two things though:

1) when I opened the bowls, one of the bowls had a lot more gasoline in it (on the side that was streaming from the vent hose)

2) The dainty piece that holds the needle was slightly bent (see photo). Is it possible that this is the cause?

http://awesomescreenshot.com/0041mric08

I am grateful for any suggestions or help.
Adam

movenon

Quote from: aslovik on August 21, 2013, 11:26:24 AM
I visually inspected the o rings and they appear like new (not surprising since the bike only has ~9k miles on it). The height of the floats also looks to be the same as the others. I noticed two things though:

1) when I opened the bowls, one of the bowls had a lot more gasoline in it (on the side that was streaming from the vent hose)

2) The dainty piece that holds the needle was slightly bent (see photo). Is it possible that this is the cause?

http://awesomescreenshot.com/0041mric08

I am grateful for any suggestions or help.
Adam

Yes that could bind, prevent full seating or cock the valve off center. Doesn't take much. Try to find out what bent it. Could have been accidentally bent during a float height adjustment. If you have the time I would put new o rings in just because...
George
Life isn't about having the best, but about making the best of what you have...

1990 FJ 1200

FJ_Hooligan

Looking at that picture, the spring needle tip (that the float persses on) is stuck in the compressed position.  I remember reading somewhere (probably in the Carb Files) that if the spring tip is stuck, the needle will not seat well and will leak.

Also, what year is your FJ?  9Kmiles isn't that many, but think about the number of YEARS those o-rings have been sitting there (assuming they are stock). 
DavidR.

aslovik

Quote from: FJ_Hooligan on August 21, 2013, 12:46:35 PM
Looking at that picture, the spring needle tip (that the float persses on) is stuck in the compressed position.  I remember reading somewhere (probably in the Carb Files) that if the spring tip is stuck, the needle will not seat well and will leak.

Also, what year is your FJ?  9Kmiles isn't that many, but think about the number of YEARS those o-rings have been sitting there (assuming they are stock). 

I just noticed that myself. I will try and loosen it or order a new one. Riding season is slipping away...

The FJ is a '93. I know, not a lot of miles. I used to ride it to work and back - but lived and worked in San Francisco, so it was only 3 miles each way. Now I am in Utah and want to do a lot more leisure riding....

Adam