Deep fuel bowl?

Ted Hamilton

Ted Hamilton

Helmet Painter / Racer
While racing a sprint vintage kart with 5hp flatty this weekend, I was getting a "bog" or delay at hard braking zone followed by a sharp right hander....like fuel starvation....no coughing, just *nothing* until a second or 2 later when it would pick up and start accellerating again. I've been told that there's a twist-in "repair" insert for the "new" carbs that makes the fuel reservoir wall higher, and fixes this, but I can't find the Briggs racing part... help please? Thanks! Other than a bad gear ratio, fuel starvation, and handling issues, it was a blast!! LOL I had fun, but this engine issue was the biggest bummer. Appreciate a pointer in the right direction. Thanks...
 
Check oil amount....to much can cause this to happen when in the turns. "I swear I put 12oz in" and the next thing you know somehow 22oz's comes out lol. Had it happen before. Might not be the problem but an easy check plus you get fresh oil! ?
 
Ted Hamilton said:
While racing a sprint vintage kart with 5hp flatty this weekend, I was getting a "bog" or delay at hard braking zone followed by a sharp right hander....like fuel starvation....no coughing, just *nothing* until a second or 2 later when it would pick up and start accellerating again. I've been told that there's a twist-in "repair" insert for the "new" carbs that makes the fuel reservoir wall higher, and fixes this, but I can't find the Briggs racing part... help please? Thanks! Other than a bad gear ratio, fuel starvation, and handling issues, it was a blast!! LOL I had fun, but this engine issue was the biggest bummer. Appreciate a pointer in the right direction. Thanks...
Click to expand...
If you overfill the fuel tank, it can cause a 'pause' while in a turn.

Did it get better as the race went on, or stay the same?
The insert acts similar to raising float level, moves fuel closer to the jet. Ie, richens.
Spark plug heat range can cause this as well.
 
This was like a full second of nothing....like there was no spark, anything....then it came back to life. I had 14 oz. of oil to start, some blew out breather, I assume I ended with around 12. And this pause phenomon was gone if the tank was full, but happened from about 1/3 of the race onward...

I will add the Briggs part -- I've seen it now -- a little metal strip with 2 notches.

And I'll start with 2/3 tank for next race. First, some practice is in order to resolve clutch issues and setup issues... Thanks for the help... Despite 4 NYS oval championships and 6 points championships, this is humbling, and like starting over! :) Never too old to start again... :)
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I would also check screen on long tube. Check passages for plugging.
New diaphram won't hurt either.

Did you mess with the needle while on track?
May not dial you in, but give some clues to what is happening.
Just some thoughts.
 
The insert keeps more fuel in the short tube cup.
Likely not the issue but too rich will cause a high speed shut off.
Yours sounds more like the fuel cup .
 
flattop1 said:
The insert keeps more fuel in the short tube cup.
Likely not the issue but too rich will cause a high speed shut off.
Yours sounds more like the fuel cup .
Click to expand...
Did you mean fuel cap?


On fuel level, always started race with 1/2 to 1 inch above rear seam with 15 degree mount.
 
The little fuel cup in the tank .
The short pickup tube gets its fuel there the long tube feeds that cup.
Happy cap was a cure as well . For the over full tank .
 
Needle was somewhere around 2T, and went to a 52 jet from a (presumed, but unmarked) 50. Was getting some popping on decel, assumed it was a bit rich, but head temps were pushing 450 because my clutch was engaging so low and working engine with a tall gear.

I'll check the emulsion tube screen when I pull tank... And where do I find a happy cap? :)
 
Ted Hamilton said:
While racing a sprint vintage kart with 5hp flatty this weekend, I was getting a "bog" or delay at hard braking zone followed by a sharp right hander....like fuel starvation....no coughing, just *nothing* until a second or 2 later when it would pick up and start accellerating again. I've been told that there's a twist-in "repair" insert for the "new" carbs that makes the fuel reservoir wall higher, and fixes this, but I can't find the Briggs racing part... help please? Thanks! Other than a bad gear ratio, fuel starvation, and handling issues, it was a blast!! LOL I had fun, but this engine issue was the biggest bummer. Appreciate a pointer in the right direction. Thanks...
Click to expand...


We've got them in stock, Ted.

Called a "tank repair kit."
It's a simple small steel band that slips into the cup in the top of the tank -- solves the problem.
You might also consider a flat(er) mount and a "Happy Cap."
Give us a call - we can ship it today.

-----
Thanks and God bless,
Brian Carlson
Carlson Racing Engines
Vector Cutz
www.CarlsonMotorsports.com
Carlson Motorsports on Facebook
30 years of service to the karting industry
Linden, IN
765-339-4407
bcarlson@CarlsonMotorsports.com
 
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