[Patrick Roth]

Jay,

In reading my comments again I can see the confusion (probably should’ve been more careful using the word “size”). I meant to imply that the size advantage for someone in football is not necessarily an advantage in karting. A 6′ 0″ 150 lb kid playing football against a 5′ 0″ 100 lb kid is likely going to have an advantage or at the very least create a safety concern which should be addressed.

In karting, a 150 lb person will be on the same level as a 100 lb person, provided the weight advantage is evened out so the the 50 lb difference becomes a 0 lb difference. The primary component of winning at that point becomes the skill of the driver. If a person is less skilled they will be at the back of the pack (out of harms way) until they become more skilled. I believe “skill” is not necessarily something I would associate with age and that “weight” should be the differentiator. :)

Cheers!

[Patrick Roth]

Good point Juan!

Matt, if what you have is a DD2 the rear axle will go through the motor case and there won’t be a chain connecting the drive gear to the axle gear. You would also have paddles on the steering wheel for changing between gears.

[Patrick Roth]

Karting isn’t a sport that the size of the person gives them a significant advantage or poses a safety risk like in football.

It seems like TaG Masters always has some sort of drama associated with it at the big races. TaG Senior and S2 shifter also seem to have their fair share of issues. Heck, I’m starting to think that I would rather race kids even if they aren’t as “mature” as the older classes…

I maintain that size should be the differentiator and not the age.

[Patrick Roth]

It doesn’t sound like you have a shifter as a Rotax 125 is used either for TaG (Touch and Go which means it has an onboard electric starter) or the Rotax specific series (Rotax Max). Any questions specific to the motor would be best posted in the “TaG” or “Rotax Max” forums. I used a Rotax in TaG several years ago and it was a solid engine package with longer rebuild intervals when compared to its competition.

If you are looking to run road racing (larger, higher speed tracks that are typically used for full sized cars) then the front brakes make be allowed; however, if you are planning to do sprint racing (typical sprint tracks will be around 3/4 miles or less in length) the front brakes will likely need to be disconnected. To confirm this, find the rules for the track/series you’ll be running and under the “Brakes” section it will clarify this. For what its worth, in sprint racing, I think most people prefer rear only brakes (except for shifters) for TaG/Rotax so if you disconnect them it will be one less headache/cost to deal with.

Where are you located?

[Patrick Roth]

My two cents is I think we should get rid of the age limits and focus on the weights. Still have the cadets for 12 and under but for 12 and older it’s full size karts.

For example for 12 and older shifters:
Light Shifter = 325 lbs with engine restriction
Medium Shifter = 385 lbs with no engine restriction
Heavy Shifter = 415 lbs with no engine restriction

In many cases this will lead to the same classes we have today but it lets weight be the determining factor and hopefully encourages those that are frustrated with the sport because of the age/weight issue to come back. I would rather race those at the same weight and I don’t care if I’m getting beat by a kid, girl, senior citizen, or someone who’s name only has two letters, etc. I’m sure this idea has been brought up before but I truly think it has merit as poor “racecraft” has no age limit.

Cheers!

[Patrick Roth]

Kudos to them for dreaming it up and making it a reality! On the other hand I see it as just another “karting” novelty like a kart with a 1300cc Hyabusa motor strapped to it, or 10,000 ft-lbs worth of electric motors, or 2 person karts, or 4 engines, or 6 wheels, or hoverkarts… ;)

Not sure what they accomplished that couldn’t have been done by taking the body off of a small FWD car? I guess by shrinking it down to a kart size, they are able to race with other non-FWD karts… Not sure I buy that it really is that good for training as lift-off oversteer seems minor in trying to learn to race a car with a relatively large amount of suspension travel and mass when compared to a kart.

[Patrick Roth]

Welcome to the kart world! While I don’t know anything about the specific model you bought I will throw some info out there to hopefully help you along.
1) Do you know what class you are planning to run? You posted in the shifter kart forum and mention a “125”. This leads me to believe you have a 125cc shifter kart package. Is this correct? If so, what brand of motor do you have? The most popular is the stock Honda 125cc but there are several other 125cc motors out there.
2) When you say “rear dual caliper brakes” do you mean you have two calipers on the rear rotor? I believe this was common to satisfy a dual braking system requirement in certain organizations. SKUSA is one of the big names when it comes to shifter karts and they require 4 wheel braking which means you need to have 3 calipers (1 for each front wheel and 1 for the rear axle).
3) The kart itself doesn’t require much maintenance. The only item that I would consider requires monitoring and maintenance are the rear axle bearings. Some people like to wash them out with brake cleaner and apply a light lubricant (Tri-Flow is a popular name) every outing, while others won’t touch them so as not to introduce any dirt and debris into the system. Either way works, it’s just what makes you more comfortable. Personally I run SKF bearings and pull them out every 3-6 months and clean them really good (they are serviceable unlike most kart axle bearing) and apply a heavy grease. I don’t do anything else to them.
4) The motor maintenance is the most work but it depends on what you have. Give us some more details so we can help.

Patrick

[Patrick Roth]

Thanks David!

[Patrick Roth]

Thanks Spencer! I tried a similar procedure and was unsuccessful; however, it could’ve been a failure of the mechanism between the stand and the ground. I’ll give it another shot next time out!

[Patrick Roth]

What do you mean tires “pounted outwards”? I interpret this as I’m going through a left hand corner and I have to turn the wheel to the right. I can only think of this happening when the rear is sliding and I’m countersteering (not a pushing condition). As long as it’s not driver induced, having the rear sliding too much leads me to reduce or slow the rate of lift.

For the sake of answering how to increase lift you can increase the front width and increase caster. A front torsion bar should help as well but wouldn’t be my first choice.

Are you expecting to see daylight between the tire and the surface?

[Patrick Roth]

I have had the Kartlift electric lift for a year and a half and like Jamie, my back appreciates the investment. I had one issue with the winch which was due to faulty electronics in which they immediately shipped out replacement electronics (at no cost) which were of higher quality (in speaking with them they had seen some failures of the electronics and had identified a more durable solution). I haven’t had a single issue with the mechanical structure and function of the lift.

One thing that I wish was different (I think this is true of all electric one person lifts) was the hooks don’t allow for the kart to have the rear picked up once the kart is on the stand. You may ask why this is important? Well, if you are trying to get the kart off of the stand and into the back of a pickup (or in my case a trailer with a “shelf”) it is impossible. Previously I had the manual one person lift from Kartlift and because of the strap (wrapped under the bumper to hold it into the hooks) it allowed me to pickup up the kart underneath the rear of the bumper (versus the electric one which I can only pick up using the spaces in the middle of the bumper). Being able to pickup the kart from underneath the rear bumper was just enough for me to position the kart at the back of my trailer, put the front wheels on the shelf, and then lift the rear of the kart off and forward to slide into the trailer.

I’ve had both Streeter and Kartlift products and while both have had superb quality and competitive pricing I tend to lean toward Kartlift because of their presence I see on this forum as well as being actively involved in the sport.

[Patrick Roth]

Brock,

How much experience does your son have driving it? What are the indicators that there is too much front grip and at what point in the corner?

[Patrick Roth]

The only time I ever experienced what you are describing (as long as there wasn’t an issue with the motor) would be when I downshifted too far (should’ve stayed in 3rd rather than go to 2nd) and I would be too high in the RPM range and any little throttle input would feel like a jerk until I shifted up (or I was too high in the RPM and hit the rev limiter).

What were the RPM’s like when you felt this? If you don’t think it is your driving may I suggest asking someone at the track who drives a shifter to take some laps in your kart to make sure it is running right.

Something that might give you an indicator if the motor is running okay is while on the stand (after warming it up to operating temp) pull the throttle to get around 7000-8000 RPMs, hold for a brief moment, and then yank the throttle and see if there is any hesitation getting to max RPMs (should max somewhere in the 14000 range). All this is meant to tell you is without a load, can the motor rev up without issue given the current setup/conditions. If there is hesitation at any point (after the inital delay from yanking on the throttle) than it’s time to start looking into the potential problems.

To follow this up under load is while on the track (pick 3rd or 4th gear), get the RPMs about 7000 and punch the throttle. The motor should bog and about 8500 it should launch to about 12500 before it loses power. Repeat this (same gear at the same point on the track) but start at 8500 and it should immediately launch to around 12500 before the power drops off.

This is assuming you are running a Honda stock moto…

As Juan mentioned, these things are brutal!!! (but ohhhhhh so much fun) :)

[Patrick Roth]

And this is why the drop down bumper idea came to fruition… It’s an attempt to take the subjectivity out of officiating yet they are damned if you do, damned if you don’t. If the drop down front bumper system were used than there would be no question whether or not the “contact” was significant or not. (BTW, I’m not a supporter of the current drop down bumper system but I do RESPECT the current officiating system with it’s flaws, regardless of whether or not I agree with their calls)

I respectfully disagree with Brock’s analysis and even more so taking it to a public forum with such pointed accusations. Rather than taking the stance of publicly chastising the decisions made by the officials, maybe consider helping in finding ways to improve the officiating or designing changes to the drop down bumper that will make it safer to use?

[Patrick Roth]

I have worn a Ribtect for several years and am extremely satisfied with the product.  I find the Ribtect 4 to be quite comfortable and very durable.  It also helps that Robby Mott is a big supporter of the karting community and is a great guy!

 

[Patrick Roth]

How the heck are you able to watch the show?  I’ve tried truTV.com but when I open the video it acts like it’s loading but after 5-10 minutes still loading.  I tried the iPad but don’t see where you can download it?  I even tried the truTV app but I don’t see the show being listed?  Help?

Disclaimer: It is likely an issue with the interface between the keyboard and the floor so spoon feeding the obvious may be required… ;)

 

[Patrick Roth]

Captain Slow,

Since no one else has taken a shot at this I’ll throw in my “any feedback is appreciated”. ;)

While I don’t have the direct mechanical experience, I recently drove some at an indoor track outside of LA last month and coming from a sprint kart I remember thinking how poor the handling was (significant push and very sensitive to snap oversteer).  I attribute a lot of this due to a massive lack of balance in weight.  Of the 600 lbs, I think 599 of it is towards the rear due to location of the drivetrain and batteries.  Here’s my thoughts:

1) First thing I would do if it were allowed would be to get rid of the rental kart tires and throw some race tires on it.  My suggestion would be to try out some MG Reds or Yellows.  The only caveat is it’s a crap shoot as to how race tires would react to an indoor surface?

2) Is there any way to weigh the kart and find out what the actual weight distribution is?  My gut tells me it would be very rear heavy and if this is truly the case I would look for any manner to shift the weight towards the front (or try adding some weight to help the balance).  For reference a sprint kart typically is around 40% front to 60% rear weight bias.

3) In terms of front end setup, I would suggest widening the front, add caster, and a little toe out.  This is what I would do with my sprint kart but keep in mind that this may just result in more snap oversteer due my belief of a massive weight imbalance.

4) Is there a way to raise the front ride height to increase the leverage resulting in more front grip?

Please note that these are things that I would do to my sprint kart and there may not be a directly correlation with the kart you are working on.  I just wanted to throw some ideas at you that might help.

Patrick

[Patrick Roth]

It definitely will not take up an inch on each side.  If I had to throw out a guess I would say maybe it would add 1/2″ total.

I have only ran the CF Ribtect seats so I can’t help you there… but… carbon fiber and stickers do make you go faster. ;)

The upper part of the Ribtect seats are quite flexible (since it doesn’t have a lip around the perimeter like most seats) and I have found that the upper part is a function of how wide you have the chassis struts.  There are limits to this but there is some room to work with.  I suggest taking a ratchet strap and putting it around the upper portion to help slide it in between your chassis struts.  Once again, there are limits to this…

[Patrick Roth]

It sounds like you were too lean on the main jet.  What does the spark plug look like?

 

[Patrick Roth]

Freddy,

I have a DDR prepped cylinder kit which is less than a year old.  While it isn’t brand new I never had a failure and is definitely going to be cheaper than new.  If interested shoot me an email at proth0303@gmail.com.

Patrick

[Patrick Roth]

Kelby,

That starts to help us out.  Is this a stock or modified cylinder?  Is the Keihin carb a PWK or PWM (if you don’t know the difference you can do a quick search as there are some pretty easy visual cues)?  Did you buy this kart/motor combination used?

If you wouldn’t mind, snap some pics of various angles of the motor and send them to me at proth0303@gmail.com.  I have a gut feeling and rather than speculating on the forum I’d rather just confirm my theory and go from there.

Back to jetting… My references are probably not going to mean much given a number of differences between my setup and yours; however, at the end of the day your best bet is to learn how to read the spark plug and piston.  I highly recommend taking a look at “Firestone Kart Info” and consider purchasing his articles.  A few of his articles discuss specifically how to read the spark plug and piston and include some very good photos.

Patrick

[Patrick Roth]

Kelby,

What I have found is there are a lot of different thoughts and opinions on everything you mentioned.  First things first, can you give more information such as:

1) Where are you located?

2) 99 or 01 cylinder?

3) Which pipe and silencer are you using?

4) What fuel delivery system do you have?  Swedetech GFS?  Pump around?  Single pump?

5) Air filter or airbox?

6) What type of carb do you have?

 

[Patrick Roth]

Bump

I also have a carbon fiber version of the plate that holds the CDI, coil, and two fuel pumps.  Currently the carbon fiber version has the pump around system mounted and plumbed and can be sold as a complete system.  Contact me if interested.

[Patrick Roth]

Bump

[Patrick Roth]

Bump

 

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