[michael smith]

im not sure.i bought it from as is and was never told the run time. it is currently at the shop being checked and they’ll let me know if it needs anything

[michael smith]

I believe that if jetting is to grow in the USA, minimum weights will have to keep up with increasing average weights of Americans

[michael smith]

Do they have a cr80 class? Shifter class, reliable, affordable, and fun

[michael smith]

According to Newton’s first law…

An object at rest will remain at rest unless acted on by an unbalanced force. An object in motion continues in motion with the same speed and in the same direction unless acted upon by an unbalanced force.This law is often called “the law of inertia.

Can you expound on how this affects cornering force?

[michael smith]

thanks . I actually found a great description in herb adams book chassis engineering. chapter 1 ,lol deals with this. basically, cornering force increases with vertical load, but not as fast as vertical load.

so . if 500lbs of vertical load is 700lbs of traction then cornering efficiency is 700/500or 1.4

if load increases to 1000lbs and traction increases to 1000lbs then cornering efficiency is lowered to 1.0 even though traction did increase.(1000/1000)

finally, say you increase vertical load to 1500lbs but traction only increases to 1250 then you have again increased traction but decreased cornering efficiency
1250/1500 or .83

thanks all

[michael smith]

ok, guys can you please break it down for me. i know weight is is generally bad, but i would like to know the science of how more weight equals less cornering grip.

reason im confused on this is that formula 1 cars, for example, usually add wing and downforce to aid in cornering force, which is essentially equal to weight but without the braking and acceleration penalty of weight in the car.

break this down for me scientifically please.

[michael smith]

Congrats.you can upload pics to photobucket and link the images here.how much power us the 250 making?

[michael smith]

Rotax
Lo206

[michael smith]

thank you a lot for that information. that gives me multiple options.

do you mind if I ask how the carbs that run without the threaded in the cap do it? ie, I see they all have a fitting at the cap. what type of fitting allows a non threaded cap.

thanks a bunch

[michael smith]

thanks for the response. in this image, you can see the hole is threaded. on my carb, it is not.

how are you guys dealing with thiss?

 

http://mtadistributing.com/Portals/0/images/Tools/Motion%20Pro/Carb/MikuniCarb-full.jpg

[michael smith]

hi,no one else has dealt with this?

[michael smith]

Hi, his tires were yhc.

But I definitely agree that too much grip is a reality, and not as fun to drive, in a lower HP vehicle.

[michael smith]

caster for me is a big adjustment.

 

on one day, i had it neutral and was running .60s, switched to minimum caster and slowed to .90s, then switched to max caster and improved to .20s

as far as the weight transfer issue, i dont think so. heres why.

my buddy was running old mgs on his lo206 engine at 370lbs. he switched to new bridgestones and it was sliding all over. i asked him to try my tires so at the track we switched but he only switched the rears. he said there was so much grip in the back of the kart that it was pushing terribly. funny enough his lap times did NOT improve over the worn set so he also agrees that there is such a thing as too much grip.

 

[michael smith]

I well try all those things.ill also try the lower psi.i thought higher psi would make it slide but no bueno.

Well they remove rear grip as well, or just front grip?

[michael smith]

update :-

I finally got my Kart together and went to the track.im running a 196cc clone honda.  my $175 seat was not supportive enough and i was fighting the kart in the turns- bad. i did 5 laps and called it a day.

 

i put a  seat in it that offered more support , lowered the front, and ran the middle (third) bearing loose. it made a world of difference.I went back to the track and  i was able to get around the track and feel like i was in control and not just along for the ride and hanging on for dear life in   the turns.

 

i was consistently running 52.40s-52.60s by the end of the day. record for the class i will eventually run is 45.xx so i have a long way to go.

i think because of my weight and the lowered front, the chassis was scrubbing the bolts in the turns(kerbs) so much so that one of the bolts holding the aluminum foot plate in front ground off a bolt and came loose. the other one was about to come loose as well. Is there a solution for this?

 

thanks to all here who offered help

[michael smith]

thanks for the invite. i had a great time. seeing the twin engine vintage karts out on the track was cool.

i also bought a bunch of stuff  i needed for not a lot of money. im now a fan of swapmeets.

[michael smith]

in  case there are other newbies like me trying to do this on a budget-

i compared racechrono using my phone’s internal gps vs the transponder at the track.

my phone has a 1hz gps refresh rate

 

three sessions

track vs ( racechrono)

84.008 ..(83.98)

81.117.. (.81.35)

80.310..(80.24)

not bad for a free product, and adding an external 5hz gps sensor via bluetooth makes it way more accurate.

[michael smith]

Happy Father’s Day to the fathers!

 

i went to the track yesterday and watched the classes run. then i went into the pits and talked to a few of them. i was very happy to see that most of the racers were happy to help and give information.

 

after discussing with the drivers, i have decided that the chonda will be the best engine for me to start with for a few reasons.

low cost, pump gas, lower maintenance, easier on tires, simple, etc

ill be ordering tomorrow .

 

thanks all for all the help and i look forward to being an active part of this forum.

[michael smith]

hi guys,

today has been a whirlwind day for me in my search for engines. THANKS ALL VERY MUCH for all your input.

I looked into the gx390, which can be bought for about $900 at northern tool. then I found discussion about the clone, which is 420cc, and can be bought for about $350 and delivers 13hp. NICE. then I found videos on it and saw the form factor. it takes up a LOT of Space. plus, it and the gx390 weigh over 70lbs !!!! OUCH.

then I was somehow led to the kt100. ok, it sounds GOOD. I love the sound of the 2 stroke, compared to the 4 cycle. its like music. then I find that it weighs in at only 21 lbs. It delivers 15hp stock, and the msrp is only $699?

am I missing something ? My undecated self is saying the yamaha kt100 is what I need, the LS1 of the karting world?

Can you all chime in on why this would not be a good choice? Im sure Im missing something

here is an article on the engine
https://new.ekartingnews.com/2014/05/28/why-the-yamaha-kt100-classes-remain-not-only-relevant-but-growing/

[michael smith]

let me ask one more question – I have a lot of methanol and would like to know – how difficult/costly is it to convert a carb over to methanol. it is a matter of just changing the carb?

what kind of % power gains can one expect?

thanks

[michael smith]

wow, thanks guys. I went back and looked and it sure does have TWO master cylinders. that saves me some money right there.

while I have your attention, I need a caliper because the chassis did not come with calipers. TS racing sells the specific one for the chassis (skm , 60-mm centers on the bolts and the rotor is almost 12mm thick. should I get the factory one or are there brakes out there that may be better performing?

thanks

[michael smith]

[quote quote=28871]Michael, I’ve been karting for 13 years, and what I try to do is beat my best at that particular track in that configuration each time I go to that track. Sometimes it might be years before you best your time. Recently I best my time at this one track by 1/2 of a second, a time that stood for 3 years prior.

Since you are a big guy, I really don’t know what motor package would be best, you did however pick out the right frame size. Have you driven anyone else kart? That might help you decide on the motor package.

Welcome to the sport of kart racing, it never gets dull, always looking for that extra that makes you faster.

Gary

#55 Honda CR80
[/quote]

Good morning, thanks for the reply. I drove an arrive and drive kart at DKC. it probably has 10 or fewer hp. It took forever to get going but it was amazing fun in the corners.

I wish I had found Karting years ago.

[quote quote=28875]Orlando Kart Center in Orlando FL started a class using a stock Honda GX 390. For your size this would be a very good option. More power than a Chonda or World Formula in a bone stock industrial engine. If your interested then contact them and see if the sell the conersion parts or complete engine.

Brian
[/quote]

thanks for the information brian. I will certainly check it out. although I dont know how much a powerful chassis will effect my need to change tires more frequently.
or let me ask this. in a more powerful engine combination, do they sell tires that can go a lot of laps, like 100, without effecting the lap times?

[michael smith]

[quote quote=28844]“I’m a big Guy.300 in full dress. Does that change your view on the engine choice or axle size?”

I’m not sure a Chonda OR an LO206 would be good for you based on your body weight. In my opinion, a two stroke, like the PRD Fireball, might be better for you. I think you would be quickly frustrated with the lower performance of those 4 cycle engines, even when you are just running laps for fun.
[/quote]

Im starting to explore other options now, including the two stroke. thanks for the advice man.

[quote quote=28847]Agree you are on the large side (okay, WAY on the large side) for kart racing. All those little guys you pushed around on the football field in high school? This sport is their revenge. If you want to stay 4-stroke, look at the Briggs World Formula. Much stronger than a chronda or L206. Pricier too, I’m afraid, but as a drag racer I’m sure you are familiar with the proportionate relationship between $ and horsepower.[/quote]

lol. funny.
thankfully I dont plan to race anyone anytime soon. . in Drag racing I am what you call a career “test-n-tuner” just trying to beat my best time. I want to do that with Karts. I also heard if you race enough you may lose some weight?

you are right about drag racing. going faster takes “cubic dollars” and winning is “just a matter of money”
speaking about drag racing. the most conntentious engine right now has got to be the ls1. Those who love it, LOVE it, and those who hate it, REALLY HATE it. it affords young people without too much money the ability to buy a cheap junkyard engine for dirt cheap, bolt a turbo on, and go ridiculously quick for a fraction of the investment of a traditional naturally aspirated drag car?

Is there an equivalent in the Kart World? ie, an engine that just offers an insanely high power-to-cost ratio?

[michael smith]

Thanks David

Let me ask a follow up. Do you recommend i start with a stock stock Chonda or will I be happier buying a prepped one.ie better cam, valve springs etc

Russ, thanks for the info. A bunch. I checked out track master and have downloaded racechrono which is a free version that does almost the same thing.

I’m a big Guy.300 in full dress. Does that change your view on the engine choice or axle size?

[michael smith]

thanks for the replies guys.

@David. i did the rental at dkc and was hooked. i drag race but this is a whole new level of fun. i plan to do ntk because the price is a little cheaper and it is much closer to me.

@Tony, thanks very much for that information. that  is exactly what i need. i looked up the gps unit and its pretty amazing eg telling you speed through a turn

@Walt- i was looking for suggestions on a kart to buy. though, i just bought a “project roller”  like 30 minutes ago.and will start building it up. it has no engine. I was going to just put a chonda in it. or would you recommend a different type of engine to start with?

about the roller i picked up. all i know is it says has a tag that says corsa, the tubes are 32mm, and the axle is 50mm.

im very excited to get started.thanks all.

 

[Author]

Posts