Carb floods like crazy!

[daspope]

Hi All, this is my first post here. I have one of those Chinese pit bikes that are pretty cheap. I picked it up about 3 years ago really cheap from someone that didn't know how to fix it... a spark plug and a few shots of carb cleaner later I had a cheap little 125cc pit bike that ran good.

Lately it was acting up and the carb just looked nasty dirty so I figured I would put a better carb on it.

I bought a Mikuni VM22 carb off ebay and mounted it up today... there is one problem...

When I turn my fuel line on, the carb immediately floods out and starts spewing fuel out of the air filter and the drain hose. So I am assuming its my floats But want to make sure there isn't some adjustment I can make on the outside of the VM22 before I rip it off and tear it apart to check the floats.

Thanks for any insight.

 

[eichkay]

Either the float level is set wrong or you have dirt at the tip of the float needle so it doesnt stop the fuel filling the bowl up.

 

[daspope]

Cool thanks. Not the answer I wanted to hear though. I was looking forward to opening up a beer, not my carb lol.

Time to rip it back off the bike.

Thanks again!

 

[daspope]

Well, took it apart, floats were set fine, put it back together and the issue is gone... I must have had some crud messing with the needle before.

thanks again for the info!

 

[daspope]

and its flooding like crazy again... I think I may be a victim of crappy ebay sellers lol.

 

[daspope]

So I have just yanked it off again looking for any kind of grime... its spotless, I am at a loss as to what could be causing this.

One thing that caught my eye, is could it possibly be my throttle cable putting too much tension on it making it think the throttle is always partially open?

Here is a pic of the spring and needle housing, the throttle cable loosened all the way and it still torques the spring to the side.

Here is a pic of down into the carb where the needle goes

and a pic of the floats

so if it is the cable my only option would be to get another cable or clip the spring... clipping the spring isn't an option to me so it would have to be another cable.

ugh, need to skip the beer and go straight to whiskey lol.

thanks for any thoughts you guys can give me on this.

 

[daspope]

So I pulled apart my old carb again and noticed its spring is about half the length of this one... so I used the old spring in the new carb with the same results... ugh

 

[my67xr]

sounds like dirt in the needle and seat still.

hold the carby upside down, remove the fuel bowl.
then remove the float pin.
carefully lift the float off the carb.
remove the needle out of the seat.
then spray some carby cleaner into the seat,
let it drain out of the fuel pipe, where the fuel line from the tank goes onto, into a container
you may find bits of dirt/plastic etc in the fuel.

reassemble once you are sure its clean then try it out.
are you running a fuel filter between the carby and tank?

if not, id be taking the tank off the frame and give it a thorough flush out, also remove and clean out the fuel tap.

refit the tank, put some fresh petrol in, and you should be right to go.

cheers, craig

 

[daspope]

Thanks I will try that now, there is indeed a filter on the line.

 

[eichkay]

fuel dumping is all about the float or the float needle and seat thats it.. nothing to do with you cable and spring..

cheapo ebay carbis are renown for bad needle seats it turns the fuel flow on and off.. they can have a poor rubber end of them which does sit down correctly or its just got some fuel tank debris holding it open..

you need to take the float out and look at the little square allot thing (float needle) and inspect its little hole it sits in

 

[emmo1980]

also put the float in a container with some petrol in it and make sure it floats it it dont float you need a new one
make sure the needle is in the right way as well test the needle and seat by holding the needle into the seat and turning the fuel on if you get fuel running down your fingers something is wrong there

cheers

 

[daspope]

yeah I just broke it down and went to town with carby cleaner on it. The cleaner expanded the gasket so I have that sitting in the oven right now to warm up, then I will reassemble and see if its fixed. if not I will consider it a loss, go get a new carb from a local shop and then put this one back up on ebay

 

[daspope]

I will test the floats too now since they are out.

 

[daspope]

Well, after tearing it down, cleaning it all out with carb cleaner, checking to see if the floats float... it still just overflows and dumps the fuel... I think I am going to give up and buy one from the local bike shop.

 

[needapitty]

yeah I just broke it down and went to town with carby cleaner on it. The cleaner expanded the gasket so I have that sitting in the oven right now to warm up, then I will reassemble and see if its fixed. if not I will consider it a loss, go get a new carb from a local shop and then put this one back up on ebay

mate dont put that carbie back on ebay for somone else to get shafted:damnmate:.............


how about you try buying a carbie from a reputable seller like dhz

 

[daspope]

mate dont put that carbie back on ebay for somone else to get shafted:damnmate:.............


how about you try buying a carbie from a reputable seller like dhz

I would put in the listing that it has the flooding issues. Someone may have more patience than me and want to fix it.

What sucks is I am supposed to go out riding with my brother tomorrow =/

I need to find a local dealer that will have a carb that fits or clean out my old carb tomorrow morning.

I know most of the people on this forum seem to be in AUS, does dhz ship to the US or do you guys know of a good dealer in the US?

 

[daspope]

Found a local shop that has the Mikuni VM22-133 (what I supposedly got off ebay for $35 USD) listed for $75 USD. ugh... I hate being in a bind

 

[daspope]

Gave it one more go and fixed it. it was indeed an issue with the fuel inlet valve. thanks to everyone that had helpful suggestions.