carb experts, new puzzle

[donwon]

ok guy's try to stay with me here. my 110 purred like a kitten and ran as fast as it could with me or anyone else on it, problem free just like you would want it to. about two months ago it started idling rough so i cleaned the carb. turns out the slow jet was clogged. well couldn't get it unclogged so ordered carb kit and rebuilt it. we all done this right, put the carb back on, gas in the tank, refrence the manual for adjustments and setting's and your off and running. well after all that i cannot get this thing to idle and when you take it down the street it's power is all over the place. so i start doing all common problem solving step one would take to get this thing right. well this is what it's come down to. the carb will purr at idle with the gas lines disconnected and only the fuel that's in the bowl. so i hook up the gas lines and it still idle's. i put just enough fuel in so it will run on reserve and it continues to idle. if i put fuel up to and over the stem used for the "on" position it chokes out. this is with the gas cap off(no vent issue) the fuel lines with no obstructions, no debree in tank, no screens clogged, no clogged tank stem's, i mean nothing wrong. drain the tank, disconnect fuel line's and the carb still has fuel in the bowl, i start it up rev it a few times and it will sit and idle again. as soon as you fill the tank it cuts out. sounds like it's a vaccume somewhere but i can't figure out where am i over looking something stupid or is this one of those 1 in 1,000,000 lottery winning oddball occurances. my neighbor thought it might be tank grimlin's so we used raid grimlin killer but it still happen's. got any idea's?

[atc007]

Sounds like your float needle isn't seating but it should be peeing gas if it isn't. Check your intake for leaks.

[Xhumeka]

Didn't happen to leave a rag or paper towel in the intake by accident (like RoscoW ;) (http://www.3wheelerworld.com/showthread.php/142041-85-250r-carb-driving-me-insane?p=1112337#post1112337) did ya??

[kb0nly]

Check your float and needle valve, pretty common to get problems there after a rebuild and it gets stuck open or closed. Also, did you use a new o-ring between the carb and intake and new intake gaskets as well if you pulled the intake off with the carb? An air leak can cause weird problems too. I was fighting a 125 for months, it would run fine then it wouldnt then it would then it wouldn't. Turned out to be with the changing temps and engine temp it would have an air leak. I ended up cutting a couple gasket from gasket material from Napa and all was well.

[donwon]

Sounds like your float needle isn't seating but it should be peeing gas if it isn't. Check your intake for leaks. i did that sealed up nice. but let's say there was a leak, wouldn't it act funny all the time as in tank hooked up or not? carb operates flawlessly as long as the tank is not hooked up.

[donwon]

Didn't happen to leave a rag or paper towel in the intake by accident (like RoscoW ;) (http://www.3wheelerworld.com/showthread.php/142041-85-250r-carb-driving-me-insane?p=1112337#post1112337) did ya?? no towel in the intake. lets say there was though, how does it run fine without the fuel lines hooked up. wouldn't a rag get wrapped around the valve causing it to run bad if at all. keep in mind it runs fine with no fuel supply.

[donwon]

Check your float and needle valve, pretty common to get problems there after a rebuild and it gets stuck open or closed. Also, did you use a new o-ring between the carb and intake and new intake gaskets as well if you pulled the intake off with the carb? An air leak can cause weird problems too. I was fighting a 125 for months, it would run fine then it wouldnt then it would then it wouldn't. Turned out to be with the changing temps and engine temp it would have an air leak. I ended up cutting a couple gasket from gasket material from Napa and all was well. i agree as a new sticky float had me cusing before,and yes new carb to intake o-ring and no it's the original gasket on the intake. i can see how an air leak would do that but my engine operates perfect with no fuel lines hooked up running only on the gas in the bowl. as soon as you hook them up and fill the tank past the "on" stem it cut's out.

[donwon]

this is my understanding that fuel flow's from both the stem in the tank "on" and the hole at the bottom"reserve" through the fuel lines into the fuel valve on the carb. from there it goes through the screen through a passage that comes out inside the carb which would be the float valve right? is it possible for it to create some kind of vaccume between the 2 fuel line at that fuel valve that sucking the float needle up and down possibly. i mean it ran fine at one point in time before all of this happend with a full tank now it act's like this. im suspecting a pin hole in that fuel valve between the two lines or something weird like that.

[just ben]

Replace the float valve(inlet valve) it sounds like it is working to a point but more fuel in the tank= more weight on the valve. There may be a specific process for testing them but what I do is blow into the inlet with the carb upright(should blow right through) then turn it upside down while still blowing.With just the weight of the float on the valve,you shouldn't be able to blow through it at all.

[Xhumeka]

no towel in the intake. lets say there was though, how does it run fine without the fuel lines hooked up. wouldn't a rag get wrapped around the valve causing it to run bad if at all. keep in mind it runs fine with no fuel supply.

I was with RoscoW when our buddy had the same thing happen (in that thread I linked) - the only way we could keep his trike running (before we knew what the problem was) was by closing and opening the petcock. Every time the trike started to die, turning the fuel valve completely off would keep it running until it started sputtering and dying again. Sounded similar to how you described filling it up only to reserve.

It sounded 'fine' and Kevin could even ride it around his yard by playing with the petcock as he rode.

But if you know there is no towel in your intake, nevermind :) Just thought I'd mention it, just in case!

[donwon]

Replace the float valve(inlet valve) it sounds like it is working to a point but more fuel in the tank= more weight on the valve. There may be a specific process for testing them but what I do is blow into the inlet with the carb upright(should blow right through) then turn it upside down while still blowing.With just the weight of the float on the valve,you shouldn't be able to blow through it at all. i see what your saying, the same problem exists with the original float valve and the new one that came with the carb kit, i guess there's a possibility that both of them are bad.

[beets442]

I've never heard of this.Yes,the fuel does come down two lines separately, one for ON and the other for reserve.
Ive had mine twisted up in there and got them crossed, but dont remember it running funny from that.
Like some how the fuel pressure is causing the float to shut off/thus bad float needle valve?

[Thorpe]

I had a bad carb kit once... Moose kit, main jet was numbered correctly, but the hole size was way too big... (Just something to look at)

Is it possible the floats are leaking, messing up your float height?

[donwon]

I was with RoscoW when our buddy had the same thing happen (in that thread I linked) - the only way we could keep his trike running (before we knew what the problem was) was by closing and opening the petcock. Every time the trike started to die, turning the fuel valve completely off would keep it running until it started sputtering and dying again. Sounded similar to how you described filling it up only to reserve.

It sounded 'fine' and Kevin could even ride it around his yard by playing with the petcock as he rode.

But if you know there is no towel in your intake, nevermind :) Just thought I'd mention it, just in case! didn't notice the link in front of my face. i see that you ment before the carb when you said intake as in the rubber boot i was thinking after carb as in the aluminum tube that bolts to the head. i had no rubber boot on when doing this the last four times and it was on the first two times with no obstruction's.

[donwon]

I had a bad carb kit once... Moose kit, main jet was numbered correctly, but the hole size was way too big... (Just something to look at)

Is it possible the floats are leaking, messing up your float height? as in floats not floating? or not seating. i thought if the float didn't seat right it would over flow out the butterfly or the vent tube. and if the floats weren't floating due to a hole in them it would do the same thing on and offish. i tore the carb apart a total of 7 times and everything is the way it should be. at one point i set all the pieces of the carb side by side and had a talk with them about acting right and doing your part then my nephew came into the garage and ask me who i was talking to. it was funny.

[donwon]

I've never heard of this.Yes,the fuel does come down two lines separately, one for ON and the other for reserve.
Ive had mine twisted up in there and got them crossed, but dont remember it running funny from that.
Like some how the fuel pressure is causing the float to shut off/thus bad float needle valve? i criss crossed the lines just to make sure but it still did the same thing.

[donwon]

i don't know this has got me stumped. tomorrow after work i'll go out there and cus it again mabey stumble onto something. like that screw driver i threw lol. guy's thank you and keep up the thoughts it's got to be something stupid.

[El Camexican]

Based on what you are saying I suspect the rubber (I assume) tip on your needle is getting stuck in the seat when the float bowl fills up with the added pressure of a slightly filled tank and is not dropping down as it should when the bowl starts to run dry. A few moments later and with the movement of you on the trike it falls back down and the process repeats. While driving you are experiencing the effects of it sticking and unsticking as you drive which causes the erratic behavior. I suggest you make sure the floats can move freely and if they can you should try changing both the needle and seat with OEM parts.

[donwon]

Based on what you are saying I suspect the rubber (I assume) tip on your needle is getting stuck in the seat when the float bowl fills up with the added pressure of a slightly filled tank and is not dropping down as it should when the bowl starts to run dry. A few moments later and with the movement of you on the trike it falls back down and the process repeats. While driving you are experiencing the effects of it sticking and unsticking as you drive which causes the erratic behavior. I suggest you make sure the floats can move freely and if they can you should try changing both the needle and seat with OEM parts. i hear what your saying and i think everyone who suspect the float is probably on to something. i'll tear into it and really go over the float part's and passage ways good and make sure the fuel valve is acting right too.

[El Camexican]

i hear what your saying and i think everyone who suspect the float is probably on to something. i'll tear into it and really go over the float part's and passage ways good and make sure the fuel valve is acting right too.

Take a real good look at everything while you're in there and make sure nothing is bent, twisted or backward. Also look at the vent lines and make sure they are clear. In they are plugged off fuel can't flow into the bowl properly.

[beets442]

I didnt see this sentence.I think this could be it too
im suspecting a pin hole in that fuel valve between the two lines or something weird like that..

[donwon]

well four more times with different results. something this speratic has to be the float. i think the fuel isn't pushing it all the way up. it kind of looks like the tabs that hold the valve might be warped a little. had a buddy give me another carb so i'm gonna swap out some parts and tryer again. thanks for your help guys and i let you know how i make out.

[donwon]

well everyone said float valve and guess what? YOUR RIGHT!!! the old one, worn down. the new one,wrong size. the one given to me, just right. popped it in and 2 pulls later "putt, putt, putt". all of you had it from the word go, your awesome. and someone gave me 500 bucks for it today. worked out great since i only had 64 dollars in it. well now the wife says i got 2 weeks to get the auto-x completed so here we go. thanks again community.

[Afrothunderkat]

Sounds like your float needle isn't seating but it should be peeing gas if it isn't. Check your intake for leaks.

I think you just fixed my tri-moto 200.

Some times it runs great, idles and runs great with the gas off, with it on it runs like trash and pours out the over flow.

Will look into this tomorrow, thanks man!

[donwon]

just rebuilt the carb on my buddys trx250x and moose racing gave him a wrong float valve also. diffrent coned shape of the rubber. we took the bowl off hooked it up to the tank and turned the fuel on and manualy pushed the floats up and neither stopped gas flow with the new one leaking the most. finally got it to stop with a junk 185s float, but that only lasted for 10 minutes of riding before it started leaking again. these moose parts aint that great.

[atc007]

If the parts are available,,it pays to just go OE. It sure does cost a lot more. But,you're fixed and fixed right ! Good job guys.

[donwon]

If the parts are available,,it pays to just go OE. It sure does cost a lot more. But,you're fixed and fixed right ! Good job guys. i agree. it's worth the extra buck to not have the hasle

[El Camexican]

If the parts are available,,it pays to just go OE. It sure does cost a lot more. But,you're fixed and fixed right ! Good job guys.

I've had nothing but good luck with getting OEM carb parts from Jetsrus and the prices are way better than the dealers