Alright, I have a 1986 with original carb and not sure if jets are orig. So, I've been having a nagging, running-nonrunning issue with the bike. It would start fine, run okay-ish until it warmed up and then I had a hard time keeping it running every time I stopped at a light. I put on a Dyna muff since the orig one was drilled out in a bad way by the PO. Did the carb setting that Lancer suggests. Still same problem as before. Checked the plug and it was ok. Pulled the carb and it was crusty. The vacuum line had gas in it too. Had the carb cleaned and checked over. Seems in pretty good condition. BUT... now, it's overflowing gas and the plug is totally wet. I've got the screw in at 1 turn at this point. It won't stay running unless I crank on the throttle. I put the idle way high but that did nothing. Pulled the carb back off and took a look at the float. No gas inside either bubble that I can tell and it seems to move fine. The little needle attached to the float seems to slide ok too but maybe something happened there that is hard to detect? Is there anyway I can test the float part to see if it sticks or the needle stays open? Are there any other factors that I can test? Once this is all figured out, I guess I should change my oil? I figure it's gotta be going somewhere besides out the overflow tubes.



Thanks for any advice.  

Initial impression ... you have several things going on, all old age related.  

Gas in vac line:  usually caused by petc0ck, especially on older bikes.  Valve starts breaking down and allowing fuel to run down vac line which fills up float bowl and spills fuel all over.  Putting the petc0ck in the "prime" position will bypass that temporarily until it can be fixed.

Crusty carb:   OOOOH, very nasty stuff.  Anytime you open a carb and find crusty crud, there is only one thing to do and that is to take the whole thing apart...every bolt, screw, washer, jet, spring, gasket, o-ring ... everything, and compare it to an exploded parts diagram to make sure you infact do have every single part that is supposed to be there.  Parts may be missing or modified (ie butchered) by previous owner/helpers.  Clean everything and be sure that ALL PASSAGEWAYS  are totally clear and free flowing.
Replace all jets, bowl gasket, 0-rings and little spring that hold the adjusting screw in.

Also, with an old bike you never know what someone may have done to the carb in the past.  Some folks think they can hammer and drill most anything and with a carb that is obviously NOT the way to treat a sensitive instrument.

The assorted tuning problems you mentioned can all be traced back to worn/broken/missing parts and clogged passageways.  There is no easy way around an old carb ... IT NEEDS TO BE TOTALLY REBUILT FROM SCRATCH.

Replacing the basic jets (pilot, main, air), bowl gasket, and o-ring w/ spring for adj screw and idle screw is cost effictive.  The needle is not too much either, but the needle jet may be a bit much and the slide w/ rubber diaphram is costly.  If that needs replacing then the total cost of the rebuild begins to approach the crossover point of getting a new aftermarket carb replacement.  Of course there is always ebay, where good deals can be found on late model carbs ... look for low milage parts just a few years old.

Buying a new carb won't fix the petc0ck.  Take care of that problem first, then see how she runs.  You can try running on prime like Lancer said, but be sure to block both ends of the vac line, otherwise gas will still leak down into the carb.

Hmmm, I got both for under $120. Not too bad. That's like getting a free petcock and not having to spend all of that time rebuilding the whole carb. (I work in a trauma hospital and I rarely have free time. It's busy season right now with all of those tiny scooters out there.  ) Hopefully, I should have my parts by the end of the week and have her on the road next weekend. I hope so. I'm having another surgery the following week and might not be able to ride for a little while.

Thanks for the comments. I'll still check the next carb and clean it up before install. They aren't exactly easy to get in and out, are they? I've become pretty quick with the fuel tank though. Although, I can get the spark plug out without removing the tank, it is a PITA.

Off the check the oil. Should I just plan on one immediate change over or will I need to do it a few times to clear the gas out? I assume Seafoam couldn't hurt?

If the slide is roughed up & the carb body that receives it is too, not sure how Id go about that,, Maybe a wooden dowel with fine sandpaper, or a folded wire to make a loop, chucked up in a drill, with sandpaper in that, spinning inside the cavity that the slide runs in? Some fine sandpaper oughta smooth the slide out. Maybe this wouldnt be all perfect, but may allow you to get to riding & not spend too much more. I dont know how rough this is, so maybe its toast,, I hope not, good luck,

Mickey X said :  It's busy season right now with all of those tiny scooters out there.  )


Are you saying those little scooters are more dangerous than the regular sized motorcycles? Or that the people who buy them have no idea its really a motorcycle, disrepect  them & crash?

Alright, I took your advice and put the new petcock in first. Still running a little rough but not overflowing the gas everywhere. I took a look in the new/used carb I got and it's filthy. When he blew his engine, he blew it everywhere. I looked at the slide body and it wasn't too bad, just dirty. I cleaned it and switched them out. Slid very smooth. I switched the float needle, just in case. Put the original carb back in. Purrrrrrs like a kitten now. This is how I imagined she should run from the time I bought her. I'll get her out for a little screaming match in a bit and see if she stays running out on the road. (right after I change the oil again) That's where I was seeing all of the problems anyway. One thing... I've tried Lancers' method of tuning the screw and I get no difference. It doesn't bog down either the whole way in or the whole way out. (I left it at 1.5 turns out.) I was trying to search on what that means, but didn't find it yet. Bigger or smaller jets? I'll check out what the new carb has in it and maybe switch them up if they will work. Otherwise, petcock is fixed and doing well and the bike idles and cranks up nice. Barely even hit the starter. Used to take a few rounds for her to catch. Interesting side effect I hadn't counted on. Thanks for all of your help. Out to do the oil and new plug.

Still need some input on the jet issue though if any of you know. I'll check what is in the new one a while, too. (btw, I put the original carb back in because it was already clean. I was anxious. )

Edit: I have a 17mm oil plug bolt. I'm thinking I remember that Craftsman sells stubby length wrenches. Anyone know? I may have to go get one. I used a short adjustable the last 2 changes. I really hate to do that tho.

Aaaaaa... I tried my regular length wrench and no matter which way I flip it, I either can't get purchase or I can't move it unless I dig a hole under it. The box end is the ratcheting type and won't fit over the bolt at all. Can't get a socket on it either. Hence the need, in this case, for a shorter wrench. I probably have one in the tool kit anyway. I just never looked. I have a hard time fitting all of that stuff back in and jamming the cover back on. So, I try not to use those unless I have no other choice.

Thanks though. Glad yours works.