carbs still leaking

so i put a whole new set of float bowl gaskets on the carbs, and they're still leaking. theyre actually leaking worse then they were before. i dont want to register the bike until i get this sorted out so i need to figure out why this is happening. i don't know enough about carbs to use specific names but if somebody can explain in dumbed down terms how to tear them down far enough to get to where there might be some failing o-rings.

 

It sounds like the needle valves are leaking. When you had the bowls off did you make sure that they were free, clean, and adjusted correctly? The gaskets really don't hold pressure, they just stop splash from escaping. I would suggest that you go through the entire cleaning, and adjusting process. Chacal has manuals that are easy to follow. There have been several posts on this topic.

 

i read over rick massey's carb cleaning guide but never having seen inside them before it was all pretty much meaningless to me. now that ive been inside the bowls it all makes pretty good sense. what exactly should i look for on the needle valves to make sure they are in good shape? what can i do to make sure they are adjusted correctly or set them so they are? while im in there is there anything else i should look for that might be causing this leaking? like i said the leaking comes from the float bowl gasket

 

Have you got the carbs off the bike?

 

im at school right now but ill have them off as soon as i get home.

 

?? RU sure they are leaking from the gasket area as this would be unusual. RU sure they are not leaking from in between the carbs therefore indicating failed o rings. BTW don't overtigthen the screws that hold the bowls on in an attempt to fix a suspected leak.

 

yes im very sure its leaking from the gasket area, when i wipe the side of the float bowl off i can see the fresh stream come out of the top of the bowl

 

Did you clean all of the old gasket, and any varnish from the mating surface before you put the new gaskets on? It only takes the smallest amount of contamination or old pieces of gasket to break the seal.

Gaskets or seals don't just simply magically prevent leaks just because they are gaskets and seals. They also require clean mating surfaces in order to perform properly.

 

yes they were cleaned when i put the new gaskets in, and it was leaking the same way before i put the new gaskets on

 

Can you post pictures of what you are talking about?

 

ok here are some pictures that can possibly help out. in the first picture i can see theres a small amount of gas on the outside of the carb bodies, but it doesnt get any higher than the top of the circled area, and its only on the back side of the carbs. in the second picture, the line is along the float bowl gasket where i can see gas leaking out of while the bike is running. in the third picture the plastic joint where the fuel line comes in is cracked on either side where the red lines are, but i dont think its leaking since its dry. i can hit it with some rtv if i need to. if the bike isnt running the leak is very slow, if i leave it over night there will only be a small puddle of gas in the pan under the first carb right under the drain screw. but if the bike is running the leaking gets worse and i have to dab the excess gas from the spot where the puddle forms with a rag to keep it from splashing around. i hope this can help somebody help me figure out whats going on

 

I think your transfer tube or tubes are leaking. Especially if you are referring to the fuel pooling up where you are showing with the bike on the sidestand.

If you can confirm that it is the transfer tubes, I would replace the center t-fitting as well as all the packings on all of the tubes. There are two transfer tubes and each one has two packings on each side, and the t-fitting does not have packings as it has rubber rings that act as seals.

Oy yeah, you have to split the carbs apart to perform that repair. But if it makes you feel any better, they lasted this long so you will never have to change them again.

 

how can i confirm what parts are actually leaking? i dont want to have to break the whole rack down and find out the problem was something simpler

 

Honestly, I don't know how to answer your question except to say look closely.

Put the bike on the centerstand so the fuel isn't running down to the left side and get a good flashlight and a small mirror so you can see between the carbs.

 

i was afraid of that. well as long as the carbs are off the bike ill check out the needle valves and after that i guess we'll have to wait and see til i get them back on. as luck would have it i just got this little round mirror thats attached to a telescoping rod for looking at stuff in hard to reach places, best $2 ever

 

Dude. If the carbs are still off the bike, get a length of hose and hook the tank up to the carbs with the petcock set to the prime position. Keep the carbs somewhat level and start checking for the leaks. You won't even need a mirror now. Make sure the carbs are still assembled or you are just going to make a big mess of fuel.

 

couldnt i just do the same thing with water? like if i attach a piece of fuel line to the inline filter and use a funnel to pour water into it, or will that leave mineral deposits that will mess with the carbs, or would that damage the carbs? i just dont want to get fuel everywhere. sorry im a n00b when it comes to carbeurators

 

no. Water (or windshield washer fluid, an oft-recommended alternative) has a different specific gravity (fluid density/bouyancy) than gasoline. If you use water or a water-based fluid you won't get the float levels right. You could use mineral spirits but that's nearly as flammable anyway.

It doesn't take much to set up a fuel-based leveling rig; you can use an empty bottle for a fuel tank (I "borrow" the fuel tank off my son's minibike.)

 

For a cheep easy test tank for fuel try the gas can that you would use for your mower ect. You can see I even use it for test rides and tuning. Just hook a fuel line up to the plastic tanks vent fitting

 

i havent gotten a chance to find out where the leak is yet, but i have another stupid question. do i have to disassemble the lower carbs before i can take off the hats and do the clunk test? or i can i do it with the rest of the carbs together?

 

You can do the cluck test from the top. Remove the 4 screws from the "Hat" and the spring and have at it. Note the needles will move off center sometimes so it nice to have access to at least one side of the carb trouts.

 

broke dirty maxim you were right. i connected the bike to the gas tank and set it to pri, and the transfer tube between the 1st and 2nd carb leaks like a mother. i pulled the tube out and the PO decided rather than replacing the old shot o-rings he would just wrap the whole thing in teflon tape and shove it back in. off to pep boys to get some new orings

 

so i fixed the leak but when i put the bike back together i start it with full choke and it revs really high so i dial the choke back in and it just dies. what should i be looking for? i did the clunk test already and everything is in order

 

did you fix the float bowl leak yet? Maybe you put the gasket on upside down and it's blocking the enrichment circuit.

 

When mine leaked from between the carb on the gas lines my o-rings were still good but the aluminum oxidizing inside the pipe never made for a tight seal. I used wd-40 & 2000 grit paper rolled and lightly sanded the inside. Cleaned it off and she's been leak free for months now.

 

it sounds like one or all of the butterflies are being held open too far.

Do you have the throttle quadrant caught under the fins on the back of the head holding it open?

Do you have the big idle knob backed off sufficiently?

Did you bench sync the rack after you put it back together?

Did you reassemble it using a surface plate or straightedge so the throttle shaft(s) aren't binding?

 

i never did 550 carbs but it seems like the floats are set too high and the intake side should be farthest from the gas because of the tilt

 

when i reassembled the rack i didnt really take much care in making sure everything was level, but they looked fine when i was done. i looked in the haynes manual, it just said to press down on the rack while tightening them down. this is frustrating i just want to ride!

 

How high is really high? My 650 maxim will rev up to 4k or so at full choke then I back it off to about 2k untill it warms up. It will continue to rev higher and higher as it warms up so you have to keep steping back the choke.

 

i got it to run for a while but i cant get it to idle. if i take the choke off completely it will slowly die. i tried playing with the idle knob but i dont think it was making much difference

 

My bike is pretty much the same way. You have to warm it up by riding it before the idle will stabilize and keep from falling off and die. I don't remember it being that way when I first got it, but I have pretty much rebuilt, and re-tuned, and properly set up my carbs and it will still do it.

I am thinking it has more to do with the electrical system than the carbs. Since the bike makes very little charging electricity at idle, the battery charges too slowly and goes down and therefore the power to make spark slowly diminishes, and it eventually dies. I thought I had it fixed before, but it has started doing it again.

 

that idle screw has really fine threads on it try watching the throttle linkage at the carb to see when it starts moving some one may have backed it out a aways.

 

i had the same problems with brand new bowl gaskets leaking. so I just made my own and have never had another problem.