Carbs leaking from float bowl gaskets after cleaning

[vandy]

I finally got around to taking my carbs off a few weeks back for a good cleaning and installed the RPM o-ring and screw kit. I also installed size 40 pilot jets and new choke plungers while I had them apart. '87 that wouldn't idle without the choke on. Put everything back together, sync'd the carbs and adjusted the idle. Bike idles and runs good. Noticed no fuel leaks while syncing the carbs, but after a few rides I started noticing a gasoline smell in the garage after the bike had been in there for a few hours. Got to looking around and a could see gas on the outside of the float bowl on carb #1. I did not replace the float bowl gaskets during the cleaning which I'm guessing was my mistake. Today I got around to taking them back off the bike to investigate further and when I disconnected the fuel line from the tank the petcock was slowly dripping gas. In the past I would get a couple of drops from the petcock but then it would stop. I know it's gravity feed on the '87's. This may be a silly question, but if the petcock did not shut off completely  would this cause the float bowls to fill up and gas to leak out from the gaskets? Or do you think replacing the gaskets will do the trick? I have gotten new gaskets from RPM already. I know this is a long post but I wanted to give as much detail as possible. Thanks in advance for any advice.

Greg

[FJmonkey]

Vandy, many "Help Me" posts normally have too little information, so great job with providing us (me) with info. The floats, needles and seats should prevent fuel flow when the bowls are filled to the float set height. However, if it is simply a leak from a gasket then fix it and your are almost done. The petcock needs to shut the fuel off when you have no vacuum (engine off). This is a safety feature so deal with it properly and quickly. The '86/'87 petcock has no rebuild kit that I know of. When mine failed I chose to get a new '84/'85 petcock from RPM. It costs a little less but I really liked the two position petcock (On and PRI). In the On position it only flows fuel with vacuum, in PRI the bowls will fill regardless of vacuum. The trade off is I lose the Electric Reserve and can run my tank dry with only a fuel light as a warning that I am low. I really don't care as I am old school and have always use my trip meter as a fuel gauge.

If you are desperate for a quick fix and handy with tools you could take the petcock apart and find the spring that holds the valve closed. Give a little stretch to make it slightly longer and provide a tad more pre-load to the diaphragm and help it close tighter. If the needle valve failed then this will not fix your problem. But before digging into that perform the Suck Test. Take the vacuum line from the intake manifold that connects to the petcock and suck on it. It should act like a straw that is pinched off and you cannot suck any more. If air is leaking in and you can continue to keep sucking then the hose and or petcock has failed. Pull the hose and check it. If it leaks then replace it and do the test again so you know the petcock is also functioning. If you buy a new petcock and not from RPM, then it needs to be Safety Wired. A few FJs have gone up in flames when the pressed in elbow fell out and dumped fuel.

[vandy]

Thanks for the info. I'll do the suck test later this evening. The last time I had the tank off for the carb cleaning I safety wired the petcock.

[vandy]

Petcock failed the suck test. At this point I might as well take it apart to see what makes it tick. Can't make it any worse! Thanks again FJmonkey.

[FJmonkey]

Petcock failed the suck test. At this point I might as well take it apart to see what makes it tick. Can't make it any worse! Thanks again FJmonkey.

I did the same thing. I wanted to see what made it tick... I took my toys apart as well when I was younger, some even worked when I put them back together... 

[balky1]

Vandy, many "Help Me" posts normally have too little information, so great job with providing us (me) with info. The floats, needles and seats should prevent fuel flow when the bowls are filled to the float set height. However, if it is simply a leak from a gasket then fix it and your are almost done. The petcock needs to shut the fuel off when you have no vacuum (engine off). This is a safety feature so deal with it properly and quickly. The '86/'87 petcock has no rebuild kit that I know of. When mine failed I chose to get a new '84/'85 petcock from RPM. It costs a little less but I really liked the two position petcock (On and PRI). In the On position it only flows fuel with vacuum, in PRI the bowls will fill regardless of vacuum. The trade off is I lose the Electric Reserve and can run my tank dry with only a fuel light as a warning that I am low. I really don't care as I am old school and have always use my trip meter as a fuel gauge.

If you are desperate for a quick fix and handy with tools you could take the petcock apart and find the spring that holds the valve closed. Give a little stretch to make it slightly longer and provide a tad more pre-load to the diaphragm and help it close tighter. If the needle valve failed then this will not fix your problem. But before digging into that perform the Suck Test. Take the vacuum line from the intake manifold that connects to the petcock and suck on it. It should act like a straw that is pinched off and you cannot suck any more. If air is leaking in and you can continue to keep sucking then the hose and or petcock has failed. Pull the hose and check it. If it leaks then replace it and do the test again so you know the petcock is also functioning. If you buy a new petcock and not from RPM, then it needs to be Safety Wired. A few FJs have gone up in flames when the pressed in elbow fell out and dumped fuel.

Hi!

There is a repair kit for 84/85. I bought it and works with two remarks: there are no diaphragms in the kit (I couldn't find them anywhere) and for some reason the smallest O-ring wasn't shutting the fuel off. Maybe it was just mine problem. I bought that O-ring in a motorcycle shop (they had the whole box of different rings), put it on and works perfectly. Here is the link to the kit if it fits to your 87: http://www.nrp-carbs.co.uk/shop/index.php?route=product/product&product_id=4140

Maybe there is a specific kit for 87 on the site, I wasn't looking.

[vandy]

I was able to take the petcock apart and stretch the spring a little, which seems to have stopped the leaking for now.

[FJmonkey]

I was able to take the petcock apart and stretch the spring a little, which seems to have stopped the leaking for now.

Glad to hear that worked, you now have a band-aid fix. Plan to replace your petcock as soon as you can. Don't mess with any chance of leaking fuel... Keep your FJ out of the scrap yard and your house free from fires by leaking fuel...

[vandy]

That's what I was thinking as well. The old p/n for the '86/'87 petcock is 1TX-24500-01-00 and that has been superseded by 1TX-24500-02-00. Anyone know the difference between the two? I found a couple of websites that have the 01 rev at a pretty good price.

[FJmonkey]

That's what I was thinking as well. The old p/n for the '86/'87 petcock is 1TX-24500-01-00 and that has been superseded by 1TX-24500-02-00. Anyone know the difference between the two? I found a couple of websites that have the 01 rev at a pretty good price.

How determined are you to keep your '86/'87 petcock? I switched to the '84/'85. You loose the electric reserve function but I never really used it any way. Now it switches my heated grips on/off...

[vandy]

I saw that you were using the 84/85 petcock on a previous post of yours and thought about that because I don't think my reserve works anyway.