(By Mike Jones & John Sefcik)
The factory recommended carb settings for the Parilla Leopard TAG 125cc kart racing engine are very safe and user friendly. The manual gives a starting point of 1-1/4 turns open for both the low and high speed needles. These are settings that allow for clean throttle response and idle and cool engine operation.
These settings in a race with experienced tuners will leave you in the dust. Assuming you adhere to the factory recommended pop-off settings of 9-1/2 to 10-1/2 psi and you're running close to the Senior Class race weight, SRS recommends carb settings closer to 1-3/4 turns open for the low speed needle and 1/2 to 5/8 turn open for the high speed needle. That curve will be relatively rich at low rpm while accelerating off turns and a relatively lean at high rpm down the straight-aways. These settings are for best performance with an experienced driver who spends maximum time at full throttle with very little off-throttle time in the corners, so proceed with caution. A novice driver should use the factory settings because, these race settings will make the engine very rich at idle and may require turning the idle speed adjusting screw to raise the idle. If you're not sure whether you qualify as an "experienced" driver, you probably don't. If you spend a lot of time off-throttle, stick with the factory settings for now.
USE CAUTION: Settings in this range (especially the high speed needle) can lead to engine seizure at high rpm if set too lean.
The settings for best performance are arrived at through a trial and error procedure. Once the engine is up to operating temperature, open the high speed needle slightly while driving full throttle down the longest straight. If you're on the rich side, the engine will flatten out prematurely (aka 4-cycling). If the engine 4-cycles down the straight, carefully reach down and try 1/16 turn leaner on the high speed needle while maintaining full throttle. Continue changing that needle until best performance is attained. When the engine no longer benefits from the slightly leaner high speed needle setting, stop leaning that needle. Then follow the same procedure for the low speed needle while exiting the slower corners on the track (assuming you've brazed a washer onto the needle so you can adjust the low speed needle while driving). Continue exploring needle setting changes in small increments for each needle until best performance is attained.
Once again proceed with caution. Leaner is not always faster. Too lean will lead to engine seizure. If you have an exhaust gas temperature (EGT) sensor, you'll typically reach the highest temperature the instant before you arrive at a braking or turn-in point at the end of the longest straight. Taking your eyes off the track to note your current EGT can be very dangerous, so SRS recommends you note the highest temperature once you're safely back in your pit area. Keep a notepad record of Track, Ambient temperature, starting needle settings, ending needle settings, highest on-track EGT and best lap time. Over time, you'll build a good historical record to fall back on if needed, so you don't start a race wondering if you have the right starting needle settings.
For more information, call us at 903-769-4140 if you have a question about your Parilla Leopard carburetor settings.
The factory recommended carb settings for the Parilla Leopard TAG 125cc kart racing engine are very safe and user friendly. The manual gives a starting point of 1-1/4 turns open for both the low and high speed needles. These are settings that allow for clean throttle response and idle and cool engine operation.
These settings in a race with experienced tuners will leave you in the dust. Assuming you adhere to the factory recommended pop-off settings of 9-1/2 to 10-1/2 psi and you're running close to the Senior Class race weight, SRS recommends carb settings closer to 1-3/4 turns open for the low speed needle and 1/2 to 5/8 turn open for the high speed needle. That curve will be relatively rich at low rpm while accelerating off turns and a relatively lean at high rpm down the straight-aways. These settings are for best performance with an experienced driver who spends maximum time at full throttle with very little off-throttle time in the corners, so proceed with caution. A novice driver should use the factory settings because, these race settings will make the engine very rich at idle and may require turning the idle speed adjusting screw to raise the idle. If you're not sure whether you qualify as an "experienced" driver, you probably don't. If you spend a lot of time off-throttle, stick with the factory settings for now.
USE CAUTION: Settings in this range (especially the high speed needle) can lead to engine seizure at high rpm if set too lean.
The settings for best performance are arrived at through a trial and error procedure. Once the engine is up to operating temperature, open the high speed needle slightly while driving full throttle down the longest straight. If you're on the rich side, the engine will flatten out prematurely (aka 4-cycling). If the engine 4-cycles down the straight, carefully reach down and try 1/16 turn leaner on the high speed needle while maintaining full throttle. Continue changing that needle until best performance is attained. When the engine no longer benefits from the slightly leaner high speed needle setting, stop leaning that needle. Then follow the same procedure for the low speed needle while exiting the slower corners on the track (assuming you've brazed a washer onto the needle so you can adjust the low speed needle while driving). Continue exploring needle setting changes in small increments for each needle until best performance is attained.
Once again proceed with caution. Leaner is not always faster. Too lean will lead to engine seizure. If you have an exhaust gas temperature (EGT) sensor, you'll typically reach the highest temperature the instant before you arrive at a braking or turn-in point at the end of the longest straight. Taking your eyes off the track to note your current EGT can be very dangerous, so SRS recommends you note the highest temperature once you're safely back in your pit area. Keep a notepad record of Track, Ambient temperature, starting needle settings, ending needle settings, highest on-track EGT and best lap time. Over time, you'll build a good historical record to fall back on if needed, so you don't start a race wondering if you have the right starting needle settings.
For more information, call us at 903-769-4140 if you have a question about your Parilla Leopard carburetor settings.
