No speed? What am I missing?

DanceDad

Member
We run a Jr Predator class, remove the governor, oil sensor. Top plate with fuel pump, green restrictior. Stinger clutch with blue springs, 16 driver. It doesn't seem to make a difference what sprocket gearing I put on, the cart has no speed. Can't even keep up on starts, or through the race. We are constantly getting lapped. I don't expect running away, but I just want to keep up. Any thoughts or suggestions appreciated.
 
Not getting full throttle, clutch, gearing, tires, just to name a few possibilities, what size track ? What rear gear with the 16 driver ?
 
Getting full throttle, stinger drum clutch with blue springs. Tried 63 in hot laps, turned 4300 and couldn't keep up with the others, went to a 60 just to try in 1st heat, turned 4100 and developed a bad push and couldn't keep up, went to a 65, turned 4500 and couldn't keep up. It's advertised as a 1/8 mile track, long straights with sweeping corners, the other carts are pretty much flat foot around it. My daughter is too, but no speed at all.
 
What tires and air pressures ? Do you feel your tires are close to the others ?
As a comparison our small 1/8 mile momentum track here a 16/54 will turn 4900 rpm, your push you developed had nothing to do with gearing, are you sure she's flat footing it.
 
Different gear ratios, different rpm's, pretty much the exact same speed. It could be the engine, it could be the rolling resistance. Alignment, bearings, carburetor jetting (he could be rich). It could be mean for that matter, how about a picture of the spark plug. Have you checked the timing of the engine? How new is the kart in the engine? Have you done a leak down test? How new are you to karting?
 
how did the plug look? Stock carb, stock jet and a green plate… it may be a we bit lean up top????
 
i would say if you haven't dyno'd the kart that the tune is off with the restrictor plate. Stock air box? What track? guys on bobs know most of them and can make sure you are in the ball park on gear and tires
 
The track is the new track in Blue Earth, MN, it's advertised as that size. Tires are Maxxis pinks and blues. 6 psi rights, 5 psi lefts. We can't do anything at the track as far as wash or prep, can during the week and they duro in low 50's. The motor is a non-hemi predator, never been dynoed, stock air box, stock muffler, we moved the gas tank. Stock carb jet.
 
Wicked , Blue Earth , MN .
Any chance its at the old location ?
98% not a chance .
Location or address Please .
 
Actually, you went fast is with the biggest gear, which should have helped your through the turns. Not by much, but coming out of the corners It should have helped.
 

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If you are trying to compete with a non hemi against the hemi you are at a disadvantage right off the bat.
 
The track is the new track in Blue Earth, MN, it's advertised as that size. Tires are Maxxis pinks and blues. 6 psi rights, 5 psi lefts. We can't do anything at the track as far as wash or prep, can during the week and they duro in low 50's. The motor is a non-hemi predator, never been dynoed, stock air box, stock muffler, we moved the gas tank. Stock carb jet.
we haven't done the stock air box with a green plate we were doing purple plates and could run the wiener pipe but a stock jet is pretty small, you likely need 3-4 sizes bigger at min on the main and .021 or so on the low speed. Really need to spend some money on jets and dyno time or maybe call dover power and ask them for suggestions and/or buy a carb, they have pretty much built it all and can likely get you within .1-.3 of max HP if you give them all the specs
 
we haven't done the stock air box with a green plate we were doing purple plates and could run the wiener pipe but a stock jet is pretty small, you likely need 3-4 sizes bigger at min on the main and .021 or so on the low speed. Really need to spend some money on jets and dyno time or maybe call dover power and ask them for suggestions and/or buy a carb, they have pretty much built it all and can likely get you within .1-.3 of max HP if you give them all the specs
Most places won't let you change anything, including jet.
Sure it isn't a setup issue?
What Kart, and setup numbers?
 
Says it cant even keep up on starts, handling is out of the question at that point. So to me either motor, clutch or maybe both.
Bad bearings, chain too tight, driver asleep, and yeah clutch, and a new driver may be getting the clutch hot before the starts
 
sometimes those motors are just duds. I have three ones average and has won several races one is a beast and one will not rev past 3500 makes less than 5hp. they say it could be bad valve sealing perhaps lap the valves and check the lash. that's the most I can confidently tell you. get it dynoed if you don't everything is speculation
 
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