Motorcycle Forum banner
1 - 18 of 18 Posts

·
Registered
Joined
·
8 Posts
Discussion Starter · #1 ·
I bought my son a Xr100r. The bike would start but soon after turning on the gas it starts pouring gas from the carb. I bought a rebuild kit, cleaned and rebuilt the carb and gas still pours from the carb soon after turning the valve. I bought a brand new carb, installed it on the bike this morning and it pours gas from the carb soon after opening the valve.
 

·
Ace Tuner
Joined
·
3,555 Posts
Are you sure you have the fuel line connected to the carburetor fuel inlet nipple and not a vent nipple?
(Vent nipple, usually located much higher on the carb body than the fuel inlet).

Don't laugh guys, I've seen it happen more than once...
 

·
Registered
Joined
·
8 Posts
Discussion Starter · #4 ·
I took the bowl off of the new carb, the float and valve look good. Everything looked good on the old carb. I’m mechanical enough to figure most things out. I’m missing something.
 

·
Registered
Joined
·
8 Posts
Discussion Starter · #5 ·
I hooked only the throttle and fuel supply line up after my last time checking everything but left it loose from the motor and loose from the air box and as soon as I turn the fuel on gas starts pouring from both ends of the carb and from the overflow tube.
 

·
Save them all!
Joined
·
4,278 Posts
Weird. Did you double check the float level in the new carb? I would almost be tempted to install the carb without the bowl and manually push the float up to close the needle. Turn on the fuel and see if it stops the fuel - sort of a messy function test.

It could also be grit from the tank or a decaying fuel hose (or petcock) jamming things up - I've had that happen more than once.
 

·
Ghost in the machine
Joined
·
2,857 Posts
Does your petcock have an OFF position? Vacuum operated petcocks usually do not.
Is the new carb OEM or Chinese?
 

·
Registered
Joined
·
8 Posts
Discussion Starter · #8 ·
It has On, Off and Reserve. It’s probably Chinese, I don’t know, I paid 50 for it on eBay. It looks identical to the old one. Plus the old one leaked just like this when I bought the bike. It leaked like this even after I cleaned and rebuilt the old one. I appreciate everyone helping, my son would love to ride the bike. I’m pretty sure that I don’t have a vent line and the fuel line switched but not 100% sure. I put it back the same way I took it off.
 

·
Ace Tuner
Joined
·
3,555 Posts
Is the vent always higher than the supply?
I would say yes, probably, always.
I looked up a 2001 year model to refresh my memory about this carburetor.
Best I can tell the vent and the supply 'nipples' are both on the left side of the carb and the supply appears to be located just above the fuel bowl.
The vent looks like it is located a little higher, sort of looks to be on the side of the bore for the slide.
An easy way to ID the vent:
Take the fuel bowl off and spray an aerosol fluid thru what you believe to be the vent. The fluid will drain down from the top area of the carb body if it is the vent.
 

·
Premium Member
Joined
·
9,892 Posts
How do we know it is a 001?
If it has on off reserve, it seems to be a non vacuum petcock. Otherwise it would have on reserve prime.
I like the idea of removing the float bowl, and holding up the float. After determining which setting allows gas to flow, turn the petcock to that position, and watch what happens. If it leaks with the float bowl up, then there is a problem with the needle valve and seat.. If it does not leak, then lower the bowl and fuel should flow. After putting the bowl back on and it leaks again, then the bowl is pushing the float up.

Bon Chance. UK
 

·
Registered
Joined
·
8 Posts
Discussion Starter · #13 ·
Thanks for the help. I’m embarrassed to report that I had the vent and supply lines backward. It was like that when we got it and I kept putting it back the same way. It’s running like a top and not leaking a drop..
 

·
American Legion Rider
Joined
·
26,018 Posts
Great!!!! Glad you got it resolved. I was with the needle being the problem bunch so I was scratching my head.
 

·
Ace Tuner
Joined
·
3,555 Posts
Thanks for the help. I’m embarrassed to report that I had the vent and supply lines backward. It was like that when we got it and I kept putting it back the same way. It’s running like a top and not leaking a drop..
Well don't be embarrassed, you ain't the first one to make that mistake.
Thanks for letting us know you took care of it. :thumbsup:
 

·
Premium Member
Joined
·
9,892 Posts
Wot Semi said.
Most of the time folks do not report back, and we never know what happened.
We have all made dumb mistakes. I nearly took out an eye when checking for TDC on my early BSA.
Plus many other not so bright repairs.

UK
 

·
Retired twice: Navy and as a govt contractor
Joined
·
15,538 Posts
Glad you have figured it out.
 
1 - 18 of 18 Posts
Top