Greetings fellow inmates....been reading all the gr8 posts and seeking info on sketchy petcock diaphram....i'm trying to get a handle on issue my 98 st1100 is having. I replaced the filter(OEM I think) and rebuilt that petcock after leak developed that led me to it last year. Cannot buy that part as far as I know, but i did find the rebuild kit, and after the 2nd effort, got it right and thought i was good to go, after running a few tanks thru it locally.
wrong again..... as i rolled for Denver from Atl, trouble day 2 rolling into Ft. Smith,AR...loss of power at speed on super slab, as I rolled nearly powerless down the exit ramp, it recovered, topped it off at gas station and made it to hotel smooth as silk. next morning I got a few smooth hours up thru Boston mtns in AR before it hit again....took the fuel filter out and it seemed clogged, so poked hole in it with phillips screwdriver, blew thru it and some black grit came out and at that point I could see right thru it(? I know, weird...maybe not stock filter?) so instead of bypassing it with ink pen barrel as planned, I re-installed it and lo and behold, she started up with full choke and running ruff, but eventually smoothed out enough to give me confidence it would run, turned it off and re-assembled bike, fired it up hoping to get to next exit, and she ran so smooth I just kept going....about 2 hrs later, 37 mi south of KC, MO and it did same thing, only this time, i could not get it back so 5 hrs on side of I-49 in this freakin heat wave later, AAA finally shows up and gets me to hotel I had reserved.
My thinking is I have trashed that petcock running w/o filter...i can see fuel in the filter body, but I could not reach the petcock with tools I had on bike, so put it in only shop that would take it
(hub cycle...seems like a good fit), they work on everything and have a ton of honda oem parts in stock, but they have serious backlog, and down a mechanic...could be a while and they may or may not get a handle on it when they do get to it, but it got the bike squared away and allowed me to return to ATL, so now I'm looking to find that kit again(cannot recall where I got it, but will find receipt this week)and get it and 2 honda oem filters delivered there just in case they do not have them in stock+ i want spares now anyway
that petcock/fuel splitter is indeed a weird animal, and reading here about all the other fuel issues, the pressure drop part is something i was not allowing for.....not real clear on exactly ***** is up with that smaller diameter hose on back side of pet cock, but reading here about pressure drop I'm now thinking it plays a very key roll in how that diaphram functions....diaphram has a spring in it and that whole design is just really strange to my eye.....but i got fuel in/out of filter and I know the fuel pump is working and the carbs are starved for fuel, and that petcock is only thing between fuel filter and carb fuel rails...it is my problem, but the problem may be pressure related also with any grit that restricts hose flow.....
anyone run across an after market mod to get that petcock out of the circuit completely? I normally steer clear of mods in lieu of correct repair, but this is clearly a weak point in the design and now that these biles are over 20 years old, running corn fuel, gotta figure that tank is nasty and grit will keep coming out.....will never travel w/o spare fuel filter again, and if I learn of a proven work around for that petcock, i'll do it.
bigger picture here is I may have to get the bike and trailer it to denver honda shop I have history with to get the tank cleaned out and all the lines replaced. Plan was/is to return the bike to Vegas storage where I had it when covid hit and resume using it for winter riding in and around sin city. That ride from denver to Kanab,UT was so mindblowing when i first made the move, I'm planning to take wife over rockies and into kanab to share it with her...assuming I can get the bike back before the snow starts flying, and that's mid-sept at elevation crossing rockies, so looking to do all I can to help insure that happens.
My main bike is ktm 1290 SA-T, so my riding season is not lost but my goal of getting the ST back to Vegas is for sure in question now, dammit. These st1100's are tanks and beyond awesome sport touring bikes, and I truly love traveling on it. added sargent seat, 2" risers on bars, had rear shock rebuilt , wrapped it this past winter(what an ass whipping that was, but worth it) and running pilot roads...it has earned all the love I can give it....it came with staintune pipes(unobtanium now) and i just marvel at it everytime I travel with it...whatever it takes to keep it running, it will get, and right now what it needs is fuel to the carbs.
deeply appreciate and value all the deep knowledge of these very special bikes on this site, beyond happy to support it and hoping a few of you have some specific experience with this petcock issue and can offer advise and links that will help me get mine back on the road faster.