First start, have a minor carb leak

O

Oinkmurphy

Member
I fired up my engine this evening for the first time (brand new out of the box) and all went well bar needing to set the idle up but I had a minor 'weep' from the float bowl on the right side of the car (see pic)

IMG_0056_zps2nkxildj.jpg
[/URL][/IMG]

Upon removing the bowl, which I had off last night for the float height check (set of 0.860 in), I noticed the gasket seems to have swollen and won't fit in the groove. It certainly wasn't like this last night so I'm just wondering if this is common or I did something wrong? Thanks in advance.



 
Let it sit overnight and the gasket will shrink back down to normal size.
In fact you may have to stretch it back out a little bit.
If you take the bowl off in between races you may not have time to wait.
Then you should have a spare gasket to use. Put the one you took out in a safe place and reuse it the next time.
 
BRIGGS Animal bowl gaskets that is a very common thing, but when you get it resealed check ur idle again, if the bowl gasket was leaking it was idling to high, when u fix ur gasket its gonna idle right back down
 
^ It would have to be leaking pretty badly at the bowl gasket for it to affect the fuel level and idle I am thinking.
What have you seen?


I'm with Jimbo on usually having to stretch the o-ring slightly to get it to fit properly.
If you're in a hurry - spray it with brake clean and it will shrink quickly for trackside replacement.


-----
Thanks and God bless,
Brian Carlson
Carlson Racing Engines
Vector Cutz
www.CarlsonMotorsports.com
27 years of service to the karting industry
Linden, IN
765-339-4407
bcarlson@CarlsonMotorsports.com
 
Jimbo said:
Let it sit overnight and the gasket will shrink back down to normal size.
In fact you may have to stretch it back out a little bit.
If you take the bowl off in between races you may not have time to wait.
Then you should have a spare gasket to use. Put the one you took out in a safe place and reuse it the next time.
Click to expand...

Thanks Jimbo, indeed you were right! However, I now cannot stretch it and hold it in the ridge to fit it back on (granted it was in the sun for about 30 mins). So if I leave it cool off will it expand a touch enough to fit it properly?

Thanks in advance guys. I'm not new to karting but new to LO206!
 
When it cools, it will shrink (that's why I suggested brake clean when it was too large.)

They are super easy to stretch with your fingers. Just be careful not to pull too hard on it -- it's much like a small rubber band - pull too hard and snap.
 
This aint rocket science.
I'm pretty sure you will get it back together.
However, you can't put the gasket in the bowl and then turn it upside down or the gasket will fall out.
If I have the carb off the engine I hold the bowl right side up in one hand and then set the carb in the bowl with the other hand. Hold the two tightly together and then I twist the bowl back and forth slightly to make sure the gasket sits completely down in the groove in the float bowl. Keep holding the two firmly together, turn it upside down and put the screws in.
If the carb is on the engine you don't have to hold the carb in that other hand but be sure to twist the float bowl back and forth to get the gasket to settle into the groove.
I had one a couple weeks ago at the track that would not stop leaking even after putting in a new gasket.
Turns out the float bowl was warped. The area above the screw was bent up so it contacted the carb flange before the gasket could seal it. First time I ever saws that.
A new float bowl fixed it.
Good luck.
Jim
 
Got it done yesterday guys, thanks. The seal shrinked a little too much to stretch it on so I tried warming it up (no joy), eventually I soaked it in some petrol for 10 minutes and it fitted on fine, with no leaks :)
 
Took the kart out for the first time on Friday and all went pretty well! However out of slower corners it hesitated a touch when applying the throttle and my carb overflow bottle had a small amount of petrol in it after the 3 sessions I did. I'm guessing I just need to check and adjust if needs be the float height again?
 
It is not unusual to have some fuel in the bottle and I would not worry about it.
If you want to eliminate it entirely route the drain hose up and over the carb or air filter before routing it down to the catch can.
 
Jim- I might ask you to reconsider the idea to route the drain hose from the floatbowl upward, in any direction. The thought here, and we've seen it play out many times: G-forces do cause spillage out of the floatbowl, through that drainage line. If the option for excess fuel to drain is taken away,that excess fuel will find it's way into the motor via the low & high-speed circuits. That effect just might lead to a loss of power due to A/F mixture being wrong. We know that these motors want to be richer on the bottom rpm curve, and leaner on the top. Convention wisdom has the float set correctly, and excess fuel draining out via the overflow tube & line as it was intended. To take it a step further, I 'd suggest two separate overflow bottle (fuel and rocker vent) so that engine pressure from the rocker vent doesn't pressurize the floatbowl.
 
Last edited:
Jim,
I think you're the one that gave me the idea to measure fuel volume from the bowl. Another way to do this is to route some clear fuel line from the bowl drain up along the side of the bowl to determine the level of the fuel in the bowl....It works great! It instantly shows a stuck inlet needle or floats bent / set wrong without even pulling the bowl. I'm going to agree with Dan and Flash that routing the overflow above the carb would be a bad idea in my opinion as well. Then again, I could be wrong -- I have been in the past. ;)


-----
Thanks and God bless,
Brian Carlson
Carlson Racing Engines
Vector Cutz
www.CarlsonMotorsports.com
27 years of service to the karting industry
Linden, IN
765-339-4407
bcarlson@CarlsonMotorsports.com
 
You must log in or register to reply here.
Back
Top