TFT Posted February 5 Share Posted February 5 There was what I thought was an oil spot on the garage floor under my XX last week after I rode it. Upon research it seems its leaking gas and that has washed residue oil with it as it dripped to the floor. I can't determine exactly where the gas is coming from. I pulled the tank off and the right side gas connection is leaking gas. Isn't the gas valve only supposed to open when there is a vacuum. It appears the diaphragm is leaking. Anyone have an experience like this? Quote Link to comment Share on other sites More sharing options...
IcePrick Posted February 6 Share Posted February 6 Pretty sure that diaphragm is known to eventually go bad and cause fuel to pass... including flooding the carbs and causing oil dilution and possibly a hydro. I guess I'd pull the fuel line downstream of the vacuum valve and see if it's passing fuel while in a no-vacuum state to help isolate the culprit. Hopefully it's leaking somewhere before the valve, maybe around the seal at the tank and running down the line before dripping off. 1997 is a fairly long time ago even considering OEM Honda quality materials, who knows what could be dried out or hardened up. If it's the worst case, I'm sure you know the drill for that - check the crankcase for fuel and pull the plugs before firing it. Not sure if there's an easier way, but if so, someone here will have the info in short order. Quote Link to comment Share on other sites More sharing options...
rockmeupto125 Posted February 6 Share Posted February 6 1 hour ago, IcePrick said: Pretty sure that diaphragm is known to eventually go bad and cause fuel to pass... +1 Quote Link to comment Share on other sites More sharing options...
XXBirdSlapper Posted February 6 Share Posted February 6 Git you one of those extra long fireplace matches, strike it up, and begin probing around the entire fuel system. That'll locate the source for sure. Best to do it in a totally dark room, and scatter a few thousand marbles or 1/2" ball bearings on the floor. Those'l help too. 1 Quote Link to comment Share on other sites More sharing options...
superhawk996 Posted February 6 Share Posted February 6 15 hours ago, TFT said: There was what I thought was an oil spot on the garage floor under my XX last week after I rode it. Upon research it seems its leaking gas and that has washed residue oil with it as it dripped to the floor. I can't determine exactly where the gas is coming from. I pulled the tank off and the right side gas connection is leaking gas. Isn't the gas valve only supposed to open when there is a vacuum. It appears the diaphragm is leaking. Anyone have an experience like this? Even if the diaphragm is working, the hoses stay full of gas so they could leak whatever's in them. Quote Link to comment Share on other sites More sharing options...
TFT Posted February 6 Author Share Posted February 6 2 hours ago, superhawk996 said: Even if the diaphragm is working, the hoses stay full of gas so they could leak whatever's in them. I pulled the tank off the bike with the petcock valve in the closed position. The minute I opened the valve gas flowed out, which it is not supposed open unless pulled by vacuum. Gas also flowed out this bottom nozzle, which doesn't connect to anything and is never supposed to do. Quote Link to comment Share on other sites More sharing options...
jon haney Posted February 6 Share Posted February 6 3 hours ago, TFT said: I pulled the tank off the bike with the petcock valve in the closed position. The minute I opened the valve gas flowed out, which it is not supposed open unless pulled by vacuum. Gas also flowed out this bottom nozzle, which doesn't connect to anything and is never supposed to do. Yep. Time for a new valve or a re-build. Wonder if Honda still makes a repair kit? Quote Link to comment Share on other sites More sharing options...
superhawk996 Posted February 7 Share Posted February 7 8 hours ago, TFT said: Gas also flowed out this bottom nozzle, which doesn't connect to anything and is never supposed to do. That's the vent for the vacuum valve so yea, problem. 1 Quote Link to comment Share on other sites More sharing options...
CALCXX Posted February 10 Share Posted February 10 Happened to my 98 in Wa. with Jeff years ago. Cracked diaphragm. Easy to replace but was difficult to get In Winthrop Wa. Made me eat pizza and drink beer for two days waiting for the part. 1 Quote Link to comment Share on other sites More sharing options...
blackhawkxx Posted February 11 Share Posted February 11 5 hours ago, CALCXX said: Made me eat pizza and drink beer for two days waiting for the part. Man the sounds rough. 😃 1 1 Quote Link to comment Share on other sites More sharing options...
XXitanium Posted February 11 Share Posted February 11 This? 1 Quote Link to comment Share on other sites More sharing options...
XXitanium Posted February 11 Share Posted February 11 eBay ? eBay 2 Quote Link to comment Share on other sites More sharing options...
XXitanium Posted February 11 Share Posted February 11 ... And he has that sexy British accent. Quote Link to comment Share on other sites More sharing options...
CALCXX Posted February 15 Share Posted February 15 (edited) On 2/10/2024 at 5:44 PM, blackhawkxx said: Man the sounds rough. 😃 It was. The pizza wan't that good. Took extra beer just to get it down. Misery. Remembered Jeff rode about 15 miles to get me some new plugs since we had the time. I think it lost power. The plugs were Autolite. (where's that poke poke button?) Edited February 15 by CALCXX Quote Link to comment Share on other sites More sharing options...
TFT Posted February 18 Author Share Posted February 18 On 2/10/2024 at 7:29 PM, XXitanium said: Thanks for the video and all the other posts with info. And thanks to everyone else who provided help. Because I wasn't sure what the problem was, the next morning I took the tank to the local MC shop. They came to the same conclusion and replaced the parts. They charged me the same prices that I saw online and only $25 for their labor. They got the genuine Honda parts quite quickly and no shipping charges. They also replaced the filter which I was unaware of until I saw the video you provided. 2 Quote Link to comment Share on other sites More sharing options...
TFT Posted February 18 Author Share Posted February 18 I just took the bike out for a run, ran it up to 140. Maybe it's my imagination but it seems to run smoother and stronger. The cleaning of the tank and the new filter may have something to do with it. I don't know if the diaphragm not functioning properly would have had any effect. Now to lube the chain and wax the bike. 3 Quote Link to comment Share on other sites More sharing options...
IcePrick Posted February 18 Share Posted February 18 I love a happy ending. Sounds like your XX will get a happy ending with the "wax on, wax off". 😆 1 Quote Link to comment Share on other sites More sharing options...
XXitanium Posted February 18 Share Posted February 18 1 hour ago, TFT said: it seems to run smoother and stronger. I'd put money on it 1 1 Quote Link to comment Share on other sites More sharing options...
superhawk996 Posted February 19 Share Posted February 19 5 hours ago, TFT said: Maybe it's my imagination but it seems to run smoother and stronger. The new parts would only help if it was being fuel starved on long heavy throttle runs, which would usually present in an obvious power loss/bucking type sensation. But it probably got all new gas which might be doing better if it was getting stale. Quote Link to comment Share on other sites More sharing options...
superhawk996 Posted February 19 Share Posted February 19 On 2/10/2024 at 12:12 PM, CALCXX said: Happened to my 98 in Wa. with Jeff years ago. Cracked diaphragm. Easy to replace but was difficult to get In Winthrop Wa. Made me eat pizza and drink beer for two days waiting for the part. I wanted to wait 'till Tom's bike was sorted before 'derailing' the thread. If you ever have an emergency with a diaphragm, or just wanna be lazy/a cheapskate like me; cut a piece out of a nitrile glove and place it over the damaged diaphragm. I recently did that for the pressure sensing switch on my compressor. It only sees about 120 PSI, worst case scen But actually, since it's being backed by the diaphragm there's very little pressure actually stressing the glove. And it's a pink glove, girl power, it's set for life. 1 Quote Link to comment Share on other sites More sharing options...
CALCXX Posted February 19 Share Posted February 19 (edited) True, you can also stop the leak, but you must also block the vacuum hose to the diaphragm or it will suck excess fuel on that cyl port making it run rich. Desperate move but it would get you home without taking it apart. My #2 98XX ran rich and also leaked fuel so I am not surprised to hear Toms XX ran better. Edited February 19 by CALCXX 1 Quote Link to comment Share on other sites More sharing options...
TFT Posted February 21 Author Share Posted February 21 I rode my XX yesterday. I was surprised how easy it started. Normally it will sputter for a while when first started and the choke on. It smoothed out almost immediately to a nice even idle. It ran very smooth and very strong. Again, I'm not sure why but is definitely running smoother and more powerful. 1 Quote Link to comment Share on other sites More sharing options...
jon haney Posted February 21 Share Posted February 21 1 hour ago, TFT said: I rode my XX yesterday. I was surprised how easy it started. Normally it will sputter for a while when first started and the choke on. It smoothed out almost immediately to a nice even idle. It ran very smooth and very strong. Again, I'm not sure why but is definitely running smoother and more powerful. Perhaps the fuel valve fix also fixed a vacuum leak? I've only had a FI Bird, so don't know all the plumbing on a Carb Bird. 1 Quote Link to comment Share on other sites More sharing options...
blackhawkxx Posted February 21 Share Posted February 21 I'm wondering if I should buy one to have just in case. Quote Link to comment Share on other sites More sharing options...
TFT Posted February 21 Author Share Posted February 21 (edited) 3 hours ago, jon haney said: Perhaps the fuel valve fix also fixed a vacuum leak? I've only had a FI Bird, so don't know all the plumbing on a Carb Bird. Could very well be. I also replaced the vacuum line with a longer one. The existing line was brittle and a bit too short so always difficult to get it connected to the tank. On another note, sure the XX is 25 years old, many bikes are much more powerful, lighter and faster. But the XX is still a scary-fast machine. And sexy!! Edited February 21 by TFT 1 Quote Link to comment Share on other sites More sharing options...
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