Calling all engine experts

[koukimunster]

To start off i realize its not a nissan nor a car but i dont really know where else to put it and i assume theres gotta be plenty of engine experts in here

So basically i took my friends 70cc honda minibike from his house that has been sitting in his back yard for like a year collecting rust and other grime. ive been fixing it up and so far so good.

the only thing is i have gas leaking problem. the bike cranks (its a kick start) but it has trouble and i seem to get really close but the closer it gets the more gas that leaks.

now i know exactly where its leaking from, but i dont know why this hole is there and how i would be able to plug it up. the hole is under the carburetor and its meant to be there but i dont know where its supposed to lead to. i dont remember anything being there so maybe its missing something.

anyhoo i took a few pictures and i hope you guys can help me out

[AZ89two4Tsx]

Why is this in 240gen?

[koukimunster]

cus it gets the most attention. thx for the help btw

[Papi Chulo]

Check the float, it could be bent... but I doubt it. Clean the jets etc etc

My 50 leaks gas like a slut, just turn the gas off. Not a big deal.

When was the last time it ran? The mixture/ idle might be off. Tighten the mixture screw in all the way, have your friend kick the bike over while you slowly open it.

[koukimunster]

ok thx ill take a look at all that good stuff tommorrow

lol its been about a year or so since it ran

would you happen to know what the pipe leading out from the bottom of my carb is?

and what do you mean turn the gas off? because if i do that then how would the bike run?

[Jyon9689]

Take apart the carb, that hole and pipe connected to it is meant to drain excess gas from the bowl. If you take the carb apart look a the gasket between the bowl and carb body and look at it's condition. There's a few things it could be, bikes don't like sitting around unless it's a new CRF450

Wish I could help you more but whenever I need a re-jet or anything major, my best friends dad is a master MX mechanic.

EDIT: If I were you I'd just throw that sucker in the backseat and drop it off at a small engine repair shop if you aren't familiar with carbs or small engines.

[CRyan]

Its going to be the float. Almost guarantee it.

God I'm glad I have an insight on a lot of things. 2 stroke/4stroke fourwheelers and boats, air conditioning, waiting tables, bartending, balancing air systems, working at small car shops, working at big dealership shops.

You'd think I know more. I do. I just can't put it to words

[koukimunster]

o ok that helps more...

and ya i took it apart and looked inside to see if it was all gunked up..to the contrary, it looked as if it was corroded and dried up inside i didnt quite know what i was looking at so i kinda just cleaned it up a bit and then put it back together, i guess ill open it back up and take see if i can see wtf is up

thx again guys any other advice is appreciated

edit: and im doing htis more for the learning experience and not to just get it back up and running..

that and im broke as fuhh so i cant be paying some shop to fix it lol

[Papi Chulo]

would you happen to know what the pipe leading out from the bottom of my carb is?

and what do you mean turn the gas off? because if i do that then how would the bike run?

If that's where the gas is coming from then It's the overflow, it's doing its job. When the bike isn't running it will still *most likely* leak gas, just turn it off when your done ridding it and run the gas out of it the carb too.

Have you cleaned the carb at all?

[Papi Chulo]

You need to unscrew the jets and clean them with a small wire.

[clss240]

carburetors are pretty simple. most are lke this.

idle is controlled by 2 similar jets:

and idle/pilot jet and an air/fuel mixture jet. the pilot jets gets clogged real easily and should be the jet that can be unscrewed using a flat head screw driver more towards the enginge side of the carb and up inside it more

ocne you hit about 1/8th throttle you now operate on the needle which is usually adjusted vie a clip on the top side of the slide(depending ont he carb if tis a flat side etc.

after about 3/4 your ont he main jet which is usually a smaller jet that sits at the very bottom of the bowl almost.

these will help you dtermine where you arent getting fuel. start witht he pilot jet then once you get it strted you may have trouble with the other jets as well. also set the idle adjuster screw up a little to help it idle.

and yeah that bottom hole is to drain the bowl.

[koukimunster]

ok so i tried cleaning out both of those pilots and it seemed to do something

but now when i try starting the bike it gets closer but it still leaks gas like a biotch...idk if thats normal tho

but ya bike actually sputters a little bit and seems like it really wants to start. it was even blowing white smoke out of the exhaust.

any1 have any ideas/suggstions?

edit: idk if it would make a difference but i can put up a video so you can see how muhc gas is coming out and you can hear the motor

[koukimunster]

ok heres a video

http://www.youtube.com/watch?v=8diIWB77zGM

idk if yall can see the smoke because youtube degrades the quality of the video but you can still hear it and tell me what you think thx!!!

at 45 seconds you can see smoke if you look carefully
Modified by koukimunster at 6:13 PM 10/23/2008

[CRyan]

ok heres a video

http://www.youtube.com/watch?v=8diIWB77zGM

idk if yall can see the smoke because youtube degrades the quality of the video but you can still hear it and tell me what you think thx!!!

at 45 seconds you can see smoke if you look carefully

Modified by koukimunster at 6:13 PM 10/23/2008

Sounds like she doesn't have much compression either

[burntricer]

sorry kinda outta the blue

but WEEEE CT70!!!! i love those things!!

[koukimunster]

Sounds like she doesn't have much compression either

ya i just took the engine off today and im gonna check all the seals and everything

another reason im doing this is because im planning on getting a gsxr 600 in the near future and i know i need my motorcycle liscence but i need to learn how to ride a motorbike 1st and for some unknown reason to me my friend doesnt wanna let me ride his gixxer lol

[clss240]

the gas leaking is most likely the float. the float is the plastic thing inside that literally floats on the gas in the bowl. like when you wheelie or tip it over the float allows gas to flow out of the bowl. howver there is also usually a screw that when unscrewed allows excess fuel from the bowl drain out. both would exit the same spot on the carb. have you already checked for spark? pull the plug and plug it back into its corresponding plug wire and let the electrode end sin on one of the fins or something metal and crank the motor over and watch for spark.(carb trouble is more likely ur problem tho)

[spooled240]

are you gonna take the minibike to the dmv to take the motorcycle test? haha

typically the float can make things extremely rich or extremely lean if it's not adjusted properly. Idk about most carbs, but a few of the ones I've seen/worked on have floats that can be adjusted simply by carefully bending the bracket that the float pivots on.

at this point there's a good chance that the float is out of adjustment and fuel is pouring in through the jets overfilling the bowl and spilling out.

Carbs are all mechanical so you can figure out how everything just from looking at it.

[clss240]

i've wrked on maybe 4 or 5 different carbs maybe 20 in total all int eh atv/motorcycle area and all the flaos here have a small almost push button type assembly that the float hits when it riases all the way which will open the bleed valve to drain the bowl. although this varies from carb-carb the float will definately be an area of concern for you as they get gummed up easily from standing gas etc. make sure it move freely, has no cracks so it cant fill with gas inhibitting its ability to, well; float. also might look into a used one off ebay or something, i believe the atc70 uses the sabe carb.

[koukimunster]

heres the picture of the float. How can i tell if its broken or not?and can any1 tell me what all that corrosion crap is? from what ive heard the carb gets "gunked" up, but that doesnt look like "gunk" to me lol

EDIT: ok the float seems in good condition it bounces with just a tap of the finger

[clss240]

that corrosion actually looks like water =/ which could aslo be the white smoke your seeing. someone may have drowned that thing at one time. or used very very old gas that had accumulated a lot of outside moisture. its be best spray the hell out of that carb (inside) with some carb cleaner and see if u can get it running if not try a new one cant be too expensive i imagine.

[koukimunster]

ya actually it was a bit flooded (the handlebars and tires all leaked out water lol)

im just gonna try and dissemble this whole engine and clean it out cus who knows how far the water got into

thx again for all your help guys

[slyedog240sx]

just put a peice of hose there with a shut off valve of some sort and problem solved

[koukimunster]

ok i finally got some time to work on my bike again...

my grandpa who is the best mechanic ever told me that like some of you said, it has low compression. so i need to buy new rings and maybe a new gasket and such.

i was just wondering where can i buy all this stuff. obviously you guys cant tell me of any shops around me since you dont live near me but maybe you guys could tell me an online site that i could order parts for, or at least what type of shop i should be looking in, like maybe a motorcycle shop or something

thx again

[cody180sx]

that like hole its leaking from is there so u don't flood the motor so it not burn all the gas might be a bad plug or so problem of that nature or the carb is not adjusted right