Predator 212cc slower than others

So I race the stock predator class at Owosso Motorsports Park and Im slower than the others, it can't be the gearing because I ran a 16 67 and it should've been fine, last time I ran a 16 65 and it was fine, but before i Changed it to a 16 67 for the heats and features, I ran a 16 63 and a 16 65 and it was still slow, the 16 67 was also slow, the weight is fine, the tires have 7 lbs left side & 9 lbs right side. So at this point it has to be our motor, im thinking we need new valve springs because they got a shorter life span because we over-redlined our motor at Arthur Raceway our first race of the year, & im sholed we didn't blow a motor, but all day we redlined it that day from 6,700 to 6,200 at Arthur because we had a 12 66 and a 13 or 14 65 I think that day, at our second race of the year we were running perfect just a little loose. Im thinking the Jetting is wrong too because im running a 0.35 and last time before this last race at Owosso, I ran a 0.36 Jetting, we ran a 16 63 and 65 gearing that day, so im guessing it's either the Jetting or needs new valve springs.
 

Hoonikart

Member
So I race the stock predator class at Owosso Motorsports Park and Im slower than the others, it can't be the gearing because I ran a 16 67 and it should've been fine, last time I ran a 16 65 and it was fine, but before i Changed it to a 16 67 for the heats and features, I ran a 16 63 and a 16 65 and it was still slow, the 16 67 was also slow, the weight is fine, the tires have 7 lbs left side & 9 lbs right side. So at this point it has to be our motor, im thinking we need new valve springs because they got a shorter life span because we over-redlined our motor at Arthur Raceway our first race of the year, & im sholed we didn't blow a motor, but all day we redlined it that day from 6,700 to 6,200 at Arthur because we had a 12 66 and a 13 or 14 65 I think that day, at our second race of the year we were running perfect just a little loose. Im thinking the Jetting is wrong too because im running a 0.35 and last time before this last race at Owosso, I ran a 0.36 Jetting, we ran a 16 63 and 65 gearing that day, so im guessing it's either the Jetting or needs new valve springs.
So its not a stock predator class? because stock at our track means you run it out of the box other than you can remove the govenor. and on stock springs your only going to get like 5400-5600 rpm. do you have a tach? are you running out of speed before the turns? Are you flat foot around the track or lifting?
 
So its not a stock predator class? because stock at our track means you run it out of the box other than you can remove the govenor. and on stock springs your only going to get like 5400-5600 rpm. do you have a tach? are you running out of speed before the turns? Are you flat foot around the track or lifting?
They require some mods like governor removal, racing flywheel, 10.8 valve springs, AKRA bug pipe and muffler, ARC AKRA legal DJ-2225 CNC Bored 0.615 carburator, stock everything else, the track wants us to run 5,900 max, yes i have a tachometer, im flat footing around the track
 

racing promotor

Moderator
They require some mods like governor removal, racing flywheel, 10.8 valve springs, AKRA bug pipe and muffler, ARC AKRA legal DJ-2225 CNC Bored 0.615 carburator, stock everything else, the track wants us to run 5,900 max, yes i have a tachometer, im flat footing around the track
Just because the track says 5900 max does not mean that's the ideal rpm’s to race at.
 
They want everyone to hit 5,900 RPM max
Trust me bud...I doubt they really WANT people too. It is pointless...can you not feel the kart lay over towards end of striaght? Trust me I have turned 5600 in a motor just like that and it was super weak up there...no power. I think you need to change your gear. What is your kart like on the restarts.
 

racing promotor

Moderator
So I race the stock predator class at Owosso Motorsports Park and Im slower than the others, it can't be the gearing because I ran a 16 67 and it should've been fine, last time I ran a 16 65 and it was fine, but before i Changed it to a 16 67 for the heats and features, I ran a 16 63 and a 16 65 and it was still slow, the 16 67 was also slow, the weight is fine, the tires have 7 lbs left side & 9 lbs right side. So at this point it has to be our motor, im thinking we need new valve springs because they got a shorter life span because we over-redlined our motor at Arthur Raceway our first race of the year, & im sholed we didn't blow a motor, but all day we redlined it that day from 6,700 to 6,200 at Arthur because we had a 12 66 and a 13 or 14 65 I think that day, at our second race of the year we were running perfect just a little loose. Im thinking the Jetting is wrong too because im running a 0.35 and last time before this last race at Owosso, I ran a 0.36 Jetting, we ran a 16 63 and 65 gearing that day, so im guessing it's either the Jetting or needs new valve springs.
You need to figure out gearing before you even consider worrying about jetting, I'd say you've never raced yet that you weren't gearbound.
 
Trust me bud...I doubt they really WANT people too. It is pointless...can you not feel the kart lay over towards end of striaght? Trust me I have turned 5600 in a motor just like that and it was super weak up there...no power. I think you need to change your gear. What is your kart like on the restarts.
I ment that's max allowed not that you have to hit that, anyways its slow on the restarts and im behind after the next lap
 
I ment that's max allowed not that you have to hit that, anyways its slow on the restarts and im behind after the next lap
If you are hitting that high of rpm in the straight then you should be taking off faster than them. Something isnt adding up. You should be needing to go down some teeth in the rear to get the correct rpm and stuff but like Brian Carlson says...a stopwatch never lies.
 
If you are hitting that high of rpm in the straight then you should be taking off faster than them. Something isnt adding up. You should be needing to go down some teeth in the rear to get the correct rpm and stuff but like Brian Carlson says...a stopwatch never lies.
Ok so my target rpm is 5,600
 

mike97760

Site Supporter
Dont confuse the max rpm rule, which is taken on the kart stand, with on-track rpms. A bone stock Predator performs best about 4900 ON TRACK. This is, in most cases, with the jet being stock. A fatter jet will raise the max performance a bit. Try 5300 max while youre on the track, and use a stopwatch to tell you when youve finally get it right. As far as jetting goes, learn to read the spark plug for color. Online are many sites that explain spark plug colors and what they mean.
 
Dont confuse the max rpm rule, which is taken on the kart stand, with on-track rpms. A bone stock Predator performs best about 4900 ON TRACK. This is, in most cases, with the jet being stock. A fatter jet will raise the max performance a bit. Try 5300 max while youre on the track, and use a stopwatch to tell you when youve finally get it right. As far as jetting goes, learn to read the spark plug for color. Online are many sites that explain spark plug colors and what they mean.
Yes probably a fouled spark plug too because it was black
 
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