I finally got the Tag karts out my brother and I bought a couple months ago. They are the old leopards. There were many issues that kept me wrenching 90% of the time, but there was one thing I didn’t get sorted out. The Birel ran great on every part of the track except the two tight right handers. It starved for fuel every lap in only those two turns. To the point where I could barely keep it running… I did a carb clean, replaced the fuel pick up line and changed the plug for the heck of it. No luck. I’m hoping a more thorough carb clean or rebuild will solve the problem. Has anyone else experienced a problem like this?
Could be something to do with the fuel pick up pipe in the fuel tank.
Sounds like he replaced the pickup though?
Have they run well for you in the past? If the carbs have been laying up, a service is a good idea. That said, you will need to test the pop off pressure to be sure that the carb is track ready. Someone else here can maybe give specifics on what your pop off pressure should be on a leopard.
This is all assuming you are using the stock Tillotson carb of course.
Another possibility is an ignition issue, although it seems logical to start with carb and go from there.
Are you sure it’s fuel related? You say it happens on only two tight right handers?
What the fuel level in your tank when your doing laps? If it is low, check the fuel “in tank” pickup line.
When you did the carb cleaning, how’d the inlet screen look?
Is the fuel inlet needle captured by the fulcrum lever?
Have you “rebuilt” the carb? Meaning replace gaskets and skins?
By chance, are you maybe resting a heavy foot on the brake in those turns?
Set pop-off at 10psi
There’s a very similar post here somewhere
This is the first time at the track with them. Can you explain what the pop off pressure is?
I have not rebuilt the carb, which is what I’m going to do next. When I cleaned it at the track I replaced the screen in the carb.
Here’s an older article that talks about popoff…
Andrew, what was your engine rpm’s at those troublesome corners (apex and exit)?
How many turns out do you have your H and L needles set at?
Could but too long/short a pick up pipe. Seems a stretch, but it’s the first thing I think of when one side cornering causes these kind of things.
Thanks for all the info guys. I’m learning allot.
Could it be electrical? A short caused by an expose wire or ?
To me it feels like fuel starvation, but I’m not ruling anything out!
Sometimes you can get hints on if it’s electrical by looking at the tacho. Erratic or otherwise unusual readings generally mean that you’re having some sort of electrical issue.
On another note, does anyone know what the compression should be? Looking to set up the spare motor and carb.
I have tons of spares and having a spare engine with carb would be helpful for trouble shooting.
It can be hard to answer with how gauges and cranking speeds can vary. Personally if it pumped 160ish I’d send it if it’s just for fun. If you’re able to, a quick visual inspection of the piston for blowby might be worth it. Same for reeds. Rebuild the carb of course as well.
I had similar problems. Turned out to be incorrectly placed inlet manifold gaskets. If the crankcase vacuum to the carbs was partially blocked, it can cause fuel starvation.