LO 206 Purple Slide Question

Hey everyone my son runs a purple slide class at our local track and I am having some issues. I have tried about almost every carburetor setting I can think of, checked the specs on the slide and have that opening to the max, and did a leak down test which shows no internal motor issues. The issue is he seems to not have as much power as the top 3 cars in his class. He has finished in the top 5 relatively consistently but can crack the top 3.

Early on I chalked it up to driving and didn't think about it to much but his driving seems to be on point his corner entry and exit are smooth, he isn't lifting, and not on the brakes he just seems to be lacking power.

Could it be a clutch issue? I am using a noram cheetah to disc clutch, its serviced and cleaned regularly and seems to work as it should. Engagement on the clutch is set to about 3000 rpm so maybe it just isn't locking up fast enough?

Just looking for some opinions or thoughts on what I can try. Thanks for any help.
 
The clutch may be an issue if its had an extended service life .
A regrind may be in order .
A more detailed description of how or why you have concluded its down on power would help .
 
I have come to this conclusion based on some rather unscientific methods to be honest. His motor does not sound as sharp as the top 3 karts in his class, when paired up in restarts with the faster karts he will lose in a drag race every time. Like i said unscientific but no matter how he drives it, which line he uses, and what gearing combination I have in the kart he does not seem to have the same level of power. All of the other karts regularly pass tech so i don't think they are cheating. Its just a box stock 206 but it seems weaker than some of the others in the class.
 
I don't want to sound suspicious, but what kind of tech do they perform after the races at your track? I don't know all the rules for that class. I don't know where that engine reaches peak torque, but your clutch should be set at peak torque. Getting peak torque transferred through the chain to the rear axle means you have maximum HP at the axle. Not saying that's going to get you anywhere, but it's something that should be done. Quite honestly, if you're losing in a drag race, horsepower at the rear wheels, or lack of same, is most likely the problem.
 
I once felt somwhat similar , i maintained the clutch . New discs set the springs etc .
Almost always gave up 2-3 spot at the drop of the flag .
Driver said it was the clutch turned out he was right . (I was not a believer)
With the 206 being sealed it tightens things some though there still could be some differences.
Dyno testing the engine is a sure way to tell if its off power .
Clutch rebuild or upgrade is simple as well .
 
Are you running the same gearing as the top 3? Is anything in the chassis causing issues? Is the toe set correctly? What is the max RPM he is nothing? Sometimes the small things can drag you down.
 
I have tried gearing all over the map. Have ran rpms as high as 5300 and as low as 4400 depending on how it is setup. Kart handles and drives beautifully with no off setups everything tracks straight and true.
 
If your racing against engines with bigger name stickers and you have out the box there could be a difference .
 
Yeah I am thinking that could be part of it and I have considered that factor as well. The next class up is jr1 at our track and they run black restrictor plate animal motors. I have a good one on my bench right now that may be my next option if I can’t get this figured out.
 
You gotta be close if running in the top 5 .
Oval or sprint ?
Keep up the praise ,small chassis , clutch and tire adjutments is all i can add .
The only other possible is valve clearance at zero .
 
It’s an 1/8 mile oval that usually has multiple racing lines so it’s not just freight train racing which is nice. I am going to try some clutch stuff this week and see if that helps.
 
I'm not a big fan of Cheetah clutches.
I really prefer the Bullys, BUT you should be able to make the clutch you have work.
Could it be possibly engaging entirely too high of rpm? (springs, weights?)
If you're getting beat on starts/restarts, that could as easily be the clutch as it is the engine down on power.
I've seen guys on too low of tire psi look bad on starts as well (ie no roll speed, especially in jr and underpowered classes.)


-----
?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
 
I got a setup bully from a local buddy of mine that has just been gone through and ready to go with engagement set to where it needs to be so the plan is to try that this week. As far as tire pressure goes is there a standard? Our track is a clay oval the tends to get rubber and faster as the night goes. I have been running 6lbs on the right side and 5 lbs on the left with maxxis pinks and blues. Any ideas?

Thanks
 
The bully will be the true test .
You are keeping notes ?
Good freind who ran up front and won , worked at improving the kart by tenths .
He would make a change and check lap times meticulously. Always looking to gain each time out . We did mass changes lokking for wholesale improvements .
Both methods produced wins , his way was more consistent.
A 1/4 -1/2 lb increase in air all around .
1 tooth less on the rear .
 
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