Help! Is it possible to be so bound up that the kart feels loose?


(Blake sholders) #1

I need some serious setup help, its an 06 margay brava chassis. Basically what im dealing with is it feels loose one lap and the next lap its hopping so bad i cant see where i am going, then the next lap its sliding bad again. Im completely confused to the point im about to just give up. None of my competitors are dealing with this problem. Im about 1 second off from the leaders when i can actually have a good lap without sliding

Heres my current setup

Front track 43inches
Hubs 85mm in as far as they go
Bar out
Max caster out (i had caster in but it was too loose, took all the caster out and gained almost a second on my lap times)

Rear track 53 inches (my engine builder from comet kart said that the margay does not like a wide rear track so i have kept it narrow)
Hubs 85mm
Rear bar is out
40mm rear axle, its not stamped but i think its a medium.
1 seat strut per side

The seat is mounted to margay specs
Kart has been scaled perfectly by comet 43% front weight.

Bridgestone ylc tires 11 psi

Engine is yamaha can.

Any help would be appreciated, im pretty desperate at this point lol

Thank you!!


(Alan Dove) #2

Have you tried experimenting with this?

Also is your chassis 2006?


(Mike Clark) #3

Blake,
Are you pretty new to karting? Reason I ask is karts can have snap oversteer pretty bad. Basically it understeers, so you keep adding steering trying to get it to turn, then what is making it understeer gets overcome and you get sudden oversteer. As a new karter it is a bit hard to diagnose as everything is coming at you pretty fast.


(James McMahon) #4

You might be experiencing what is called “Push, Kick”.

The kart feels bound up (pushing, under steering) on entry, so you’re probably adding lock. When the front end finally catches up, the rear breaks loose.

As for xxx kart not liking yyy setup, unless the conditions are similar, especially regarding driver weight, body composition, tire compound and seat position I wouldn’t take too much notice of that. If I have my seat 1/2” higher than someone else the kart is going to tend to want a wider rear. It’s all relative, especially at club and regional level.

What works, works. Finding what works it is the fun part. You’ll get there :wink:


(James McMahon) #5

Also, if you have a video sample that would help.


(Blake sholders) #6

No ive been racing this kart since 2011 in Yamaha can. I completely updated it over the winter with new hubs, seat ect. It used to have short rear hubs and dsm front wheels. This is a totally new track for me, ive never dealt with this issue before with this kart. We are also racing on sealer which doesnt help


(Blake sholders) #7

James i wish i did lol


(TJ Koyen) #8

Regardless of what Margays “like” or “don’t like”, I think it’s worth trying to widen the rear. The kart sounds unstable, and with a super narrow front and a narrow rear, that’s to be expected. Widening the rear, or the whole kart can really settle it down. That would be my first tuning adjustment.

That being said, if kart is handling one way on one lap, changing completely the next lap, and then changing again the next lap, that’s likely down to some driving issue. The kart, regardless of its handling deficiencies, will remain relatively constant throughout, other than expected tire drop off. Having the overall kart as narrow as you do could be contributing to that though, as it would be harder to drive if it were so unstable.

I recommend starting with widening the rear 1/2" at a time until the hop goes away. Then start widening the front to counter any understeer you encounter.


(Blake sholders) #9

Thank you so much for the input Tj! Its very much appreciated!!


(Blake sholders) #10

Yes i have tried experimenting with the rear track, i hovered around 53 to 53 and a half though. Yes its a 2006 margay brava 1.6 limo


(Alan Dove) #11

It’s an old chassis so you might end up spending far too long chasing something that you’ll never find. The chassis itself is a set up component itself. We can vary widths all day long, but the chassis itself could be the fundamental problem.

I presume you’ve checked for cracks etc…? Have you tried a different kart?


(Blake sholders) #12

Yes ive checked for cracks, i tore the kart apart over the winter and replaced everything except the frame, front spindles and the rear axle which i had checked for straightness by comet. For what i put into this i could have bought a really nice used kart. I started restoring it and became obsessed lol. No i have not driven any other kart, just this one and my previous margay which was setup for the old clone class. As far as the frame goes there are zero cracks and its not bent , the tubes are not ground down. Ive owned it since 2011 and raced it maybe 25 times total, never wrecked it. It was a good handling kart. Im starting to think i may have just bought to large of front hubs and its caused all this mess


(James McMahon) #13

For sure I would be thinking about any changes that happened over the off season during the chassis refresh.

If the offset of the hubs is different the you have a variable there for sure.


(Blake sholders) #14

They were dsm front wheels and i wanted to go more modern so i chose to go with hubs, the guy at comet said a medium hub would be a good choice so i went with medium hubs front and rear, both are 85mm. The first practice day i was around 44and a half front width and 54 rear, had some caster dialed into the front and it was just ridiculously loose mid corner so i narrowed everything up. Ive reset the kart back up to those exact settings and kept the caster out and the front bar out. Gonna go practice Saturday if the rain holds off! Thank you for the help!


(TJ Koyen) #15

Good plan. Whenever possible, try to run with less caster. Sometimes it’s necessary, but it can also cause issues because of how much weight jacking it provides. Going back to your baseline setup and removing the caster would be what I would do too.


(Luca den Hartog) #16

maybe it is that the front has to much grip compared to the rear. I used to have a similar problem with my otk which we fixed by simply maken the front smaller. we always had the rear at the max width.


(Matthijs Hofman) #17

Have you asked someone else, whose opinion you trust, to give it a go in your kart? If he or she feels the same issues, it’s down to your kart or setup and if he/she doesn’t, it’s probably something related to your driving style.


(Blake sholders) #18

The points leader is going to drive it next time we are both at practice! I moved the rear hubs out to 54 1/4 and it instantly felt more secure but still had a hop in the tight down hill corner so i bumped each side out 1/4 and it feels lots better. I have a bruised rib at the moment so i wasnt able to push as hard as i wanted to or practice for very long. Hopefully my rib is healed up by this Saturday and i can let you all know if it works. Definitely going to buy some short front hubs here soon! Thanks again for the help!


(Dom Callan) #19

Watch it with that rib. If it’s just bruised, don’t break it!


(James McMahon) #20

Rib ailment aside…Which is faster?