225dx carb problems still

[crownpoint]

I have an 85 225dx. i've taken the carb completely apart and replaced a couple parts that looked bad. got a new gasket for the float bowl and got it together and still have problems. there is too much fuel in the bowl. i know this because its leaking out the bottom of the carb where the drain is. i thought the screw was the problem but after replacing it and testing it now i know the fuel is coming out of the brass pipe that drains the fuel if the level is too high.

besides the fuel coming out the drain the machine runs ok with the choke on. as soon as i put the choke off the idle goes up very high and i can't seem to turn the idle screw enough to make it ok.

the needle valve and the float looked ok to me so i think its the float level. does this sound right and what is the correct level for this float? i set the main screw on the bottom to 1 and a half turns. i read in a post that this is where it should be and everyhting else is tightened down. by the way it smokes alot.

[Erics350x]

you need to adjust the float and the mixture screw in front of the fuel bowl. all the other screws/jets should be tight

[crownpoint]

well i took the carb apart again and raised the pin on the float that operates the fuel coming in. now the choke and idle are dialed in ok but it misses a little sometimes at idle, like it doesn't have fuel then the drain on the bottom starts leaking a little bit like its got too much fuel in it. can anyone tell me the correct height for the float and a way to measure this? thanks

[traxxasx]

Look take your carb off.
HOld uit up right and "blow" air into the gas inatke tube. Air should go in fine?
Now, flip the carb upside down and blow air into it, if are stil goes in while it upside down its not sealing off. Take the bottom of your carb off the "bowl" and Where the float it self is, the little thing that sticks out, the thing where you slide the needle onto on the float. Well bend that little flap just a little so it will seal faster and tighter. Hope this helps.


ALso there is no :PIN: to raise the float i suggest what ever pin your refering to put it back where it was.

[crownpoint]

yeah the flap is what i bent, guess it isn't much of a pin but thats what i meant. i've already blown through the gas line and the needle valve that connects to the flap seems to work fine. what i'm wondering is if there is a definate place that the float should be. i don't want to keep taking this apart more then i have to.

[traxxasx]

The float has only only place as to where it should be. Make sure your float is not upside down. ALso i took mine off to replace a jet, i put it back on right. Well i turned my gas on and it was pouring out the bottom on the carb, well i knew the float was right, so wacked the carb with a hammer( not to hard now) and it fixed it, somtimes the float can get stuck.

[crownpoint]

the float upside down suggestion sounded pretty good but when i flipped it the bowl would not shut over it so it seems that there is only one way to put it on. it seemed to me that the carb was not the problem because it seems fine so what else could it be. maybe it wasn't getting air so things were getting screwed up and it was pulling way too much fuel throught the carb, when i opened the back where the air filter is it looked terrible. i ran it without the filter for a couple minutes and it ran much better. i think this is probably my problem. so i have another question.

whats the best way to clean one and how do i know when i have to buy a new one?

[traxxasx]

I highy doubt your problem of overfloding gas is because your filter. You needle is npt seating right your carb is not stoping the gas, which is couaing it to overfill the carb. Th best way to clean the filters is to take the actual filter off the cage, then use dish soap and wash it real good with water. Let it dry then take some motor oil and pour oil all over it till its soaked then squeeze the extra oil out like a wet shirt and then reinstall it. They last until the rip.

[crownpoint]

thanks i'll clean it and give it a shot. if the problem persists i am going to try replacing the needle. i am running out of things is could be. the upside of this is i am learning more then i wanted to about these carbs...

[Unclediezel]

Sounds like the float is leaking. If there is a leak in the float it will sink to the bottom of the bowl and it wont shut th gas off. Blowing into the carb is the right thing to "Bench Test " it ---but it doesnt simulate actual gasoline in the bowl.
Get a bucket of water, take the float out of the carb and leave it in the bucket overnight. it shoulnt sink at all. if it does -replace the float.

[tolowhb]

Hello, Im not trying to thread jack you, but I am similar situation (although I have replaced my carb but no luck!) Any ways for Air/fuel mix is it the screw on the bottom of the carb???

[Erics350x]

yes the mixture screw is on the bottom of the carb.
also if youre gas cap isnt venting the tank will pressurize , causing the carb to leak fuel.
the best way i found to set a float is to take the bowl off , turn the carb upside down and set the float where its level when closed.

[traxxasx]

Hello, Im not trying to thread jack you, but I am similar situation (although I have replaced my carb but no luck!) Any ways for Air/fuel mix is it the screw on the bottom of the carb???


No its not, its the big one on the left side that you can twist with your finger and it also have a philips slow so you can use a screwdriver, and there is a spring on it to tension it so it wont move.

[tolowhb]

No its not, its the big one on the left side that you can twist with your finger and it also have a philips slow so you can use a screwdriver, and there is a spring on it to tension it so it wont move.

I thought that one was the idle screw? Then there is a little one next to it and a screw for the bowl drain. And one more on the very bottom of the carb. Correct?

[traxxasx]

I thought that one was the idle screw? Then there is a little one next to it and a screw for the bowl drain. And one more on the very bottom of the carb. Correct?


Yes it is the idle screw, there isent an air/fuel mixture screw. The one on the bottom is to open and close the bottom of the bowl to drain extra fluid.

[junkrider]

Wow. Okay. If your carb leaks fuel, simple rule: You're getting too much fuel.
This can be caused by the following:
1) Float valve stuck
2) Jetted wrong
3) restricted air cleaner (causes a "choke" condition).

First of all, stop the leaking. Make sure your vents breathe (cap vent works?).

Check the float level (see above post about how float will be level if carb is held upside down with the bowl removed).
Make sure there is no obstruction in the float valve passage (dirt can cause the float valve to stay open). Make sure the float valve is clean, not worn.

If that is good, and the float is level, you should never leak fuel from the carb unless the bike is upside down. If it leaks, then your float's not working.

The air/fuel screw (if the bike is equipped) is only for idle mixture. It does nothing at higher RPM. Only adjusts the idle air/fuel.

A screw about 1/4 way up on the side of most carbs is "IDLE SPEED". It physically limits how far down the cylindrical slider rests in the carb. The lower the cylinder, the more restriction, and lower the idle speed. Turn the screw in (clockwise) to raise idle speed.

A screw on the side, near the base of the carb, usually at an angle is the air/fuel. This is for idle mix only. If the bike is missing at idle, you can sometimes tune it in with this screw. If you can't, or the adjustment makes no difference, the idle passages are dirty or the idle speed adjuster is set wrong (either too low, doesn't run, or too high, revs beyond idle range.)

If the bike runs like crap at higher RPM, or backfires, then the main jet is either dirty or the wrong size.

YOU GOTTA BE WILLING TO TAKE APART A CARB AND CLEAN IT RIGHT.

Take it apart, take photos, make drawings, take notes, etc to make sure you can get it back together properly. Don't turn screws in like a maniac with a fat screwdriver till you bottom out the screws and damage the seats and needles. Take it easy. No use spending $300-400 on a new carb cuz you monkeyed it to death.

Clean everything with carb cleaner. Carefully blow out the needles, jets, and passages with compressed air.

Reassemble the carb and adjust it to spec. Gently bottom out the air/fuel screw and back it out 2 and 1/4 turns or so. Then turn on the fuel, see no leaks, be proud.

Start the thing, adjust the idle speed, and adjust the air/fuel.

Sounds like a pain in the butt, but how much time have you already spent on fixing it? And, so you buy a used carb for $40 on ebay, guess what... The dude your buying it from probably took it off a bike that sat for 3 years with fuel in the carb. That carb will need cleaned too. So, you're just better off cleaning the carb right the first time.

Trust me, it's a pain. But it gets easier and easier each time you do it right. I used to send carbs to shops. Now I can tear down a carb and clean it right, adjust it and have the bike running in about 20 minutes or so.

[Erics350x]

Yes it is the idle screw, there isent an air/fuel mixture screw. The one on the bottom is to open and close the bottom of the bowl to drain extra fluid.
the mixture screw is just in front of the fuel bowl , going up in to the carb from the bottom.

[tolowhb]

the mixture screw is just in front of the fuel bowl , going up in to the carb from the bottom.

Yes! This is the screw I was wondering about!

[crownpoint]

ok i'm following all of this. i am going to replace the spark plug today and test it. last night it ran ok without the air filter so i've cleaned it and will see if thats it because i am pretty sure the carb is not the problem.

the carb leaks gas when its running not when it sits. i do have one question and this will probably help you too tolowhb its this:

what about the phantom screw. it is a machine screw that is between the idle screw (big one with the spring) and the engine. to me it looks like a good place to squirt starting fuel into if it won't start. maybe this is for testing vaccum or something?

i'll know today what the problem is/was. thanks for all your help

[edog]

DO you have a Digital Camera?

[junkrider]

i believe that screw is the idle speed.

if it leaks gas at all, the float valve is somehow malfunctioning.

I'm not aware of any carb with a starting fluid port. Some carb boots (intakes) have vaccuum hookups, but thats for balancing carbs on a multi carb system.

[Erics350x]

did you try blowing threw the gas cap vent? sounds like the float is just a hair to high to me.

[3 weelin geezer]

I think he also needs to know how to measure the float height. Does anyone know the specs on that? As far as the cleaning, take it apart first. Make sure you have ALL the rubber parts off of it and toss everything metal into a can of berrymans carb cleaner for a while. It sez to leave it in there for 15-30 minutes but I left mine in at least a couple of hours (while I worked on other stuff, my gun build or just screwed around on the internet) and it cleaned it very well. The Bayou now purrs like new instead of coughing and gagging like an old man that smokes. Now for the air/fuel mix is about 2 to 2.5 turns out. Both of mine have been about 2 1/8 turns and they work fine. Some bikes let gas out of the tank only when they are on using engine vacuum to open up the valve in the petcock so thats why yours might be leaking only when it runs. (I do not have a picture of that petcock and I don't own one so I am not familiar with it but I do have a vulcan that works like that. )

[crownpoint]

i cleaned the carb fully, it can only be the needle/float valve at this point. the screw i mentioned is a machine screw that comes all the way out or all the way in. i'll snap a pic of it tomorrow. i am waiting on the float valve and should get it thursday then i'll know for sure.

[crownpoint]

the screw in the middle of the image is the one i am curious about.

[tolowhb]

the screw in the middle of the image is the one i am curious about.

I wonder about that screw as well, seems like it would be to loose to be A/F ratio screw. I have a blurry pic of what I thought could be the a/f screw. Here it is circled.

[Unclediezel]

I wonder about that screw as well, seems like it would be to loose to be A/F ratio screw. I have a blurry pic of what I thought could be the a/f screw. Here it is circled.

Youre absolutely correct! That is the pilot -air screw.

[crownpoint]

well i replaced the float valve and that seems to have fixed it. the guy up the street who works on these says he replaces the float valves on every carb he fixes because they go bad so often. says the additives in the gas kill them. i took thefox 's advice and got the moose kit for this machine and it worked out good. now to deal with the burning oil issue.....