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Jeff, I’ve never used the magnetic sensors, but most likely the obscuring time is the problem. I’d guess you’re right that you need to be shorter than the shortest sector.
@Road Runner wrote:
This past weekend at The Track Mychron was acting screwy.
Would rev the motor and the RPM gauge wouldnt keep up with it. Ex, At full throttle it would sho like 500 rpm then as I let off the gas and it slowed it would jump up to say 4 or 5 thousand RPMS.If you still have the little plastic clip on the RPM cable, throw it away. That thing is junk. Zip tie the RPM cable directly to your spark plug wire. It can even help to wrap it around the wire a few times.
Also, make sure that the RPM cable is not tied to any cables other than the spark plug wire. If it’s attached to any of your other ignition wires, or other sensor wires for the MyChron, that could be screwing up your readings.
@Road Runner wrote:
And would give bogus lap times like 1:4’s and 1:5s, when i know i was sub 59s.
Two potential problems there that I can think of off the top of my head. First, the obscuring time may be messed up. After the MyChron registers a lap, it ignores all further laps for a certain amount of time. This amount of time might be set too long – check your manual to see how to change it, and set it to something like 50 seconds. The other potential problem is your sensor could be mounted such that your leg or something is getting in the way, or it’s just not lined up well enough to be able to “see” the beacon next to the track.
Hopefully some of this works… if you absolutely can’t get it to work, AIM’s customer service is pretty good and will take care of you.
We set up our engines (Rotax and otherwise) so that they will not idle. The reason is, when I’m not on the throttle and under braking, I do NOT want the engine pushing me forward, not even a little bit. It’s a very minor difference, but it does help just a tiny bit under braking. I don’t mind holding the throttle open slightly when idling in the pits.
Also, if you allow the engine to idle when you’re coming off the track, that tends to load the engine up with fuel, which makes it difficult to get an accurate spark plug reading to determine jetting. Better is to “hot chop” the engine. Basically, this entails running the engine at full racing speed (high RPM) then completely releasing the throttle and coasting into the pits.
Gearing… that’s kinda a judgment call. Both the straight and the slowest corner are important considerations. Generally the slow corner will be most important in a TaG, particularly if you running against a variety of engines (TaG as opposed to Rotax only). It’s often very worthwhile to work specifically on driving around the slow corner faster, which allows you to run a lower gear which gives you a little more top end.
A couple general rules:
-If you’re not revving out on the straight but are ok in the slow corner, you may want to add more gear
-If you’re in the powerband out of the slow corner but are topping out halfway down the straight, that’s probably fine.
-If you’re not in the powerband out of the slow corner, you should do everything possible to get there – unless you like getting passed 😉Charles is right on for gearing. His jetting advice is very sound too, for MOST Rotax engines. We’ve found over the years that a few Rotax engines like to run different jets than is usually considered normal. We had one engine that was an absolute dog until we put a 140 in it, and we were running 148-150 in all our other engines!
The MaxJet is useful as a baseline tool, but you will still need to experiment to find the optimal jetting for your kart.
In this case, gearing was most likely your biggest problem. If you haven’t thoroughly cleaned your carb and power valve in awhile, I’d do that too just to make sure everything’s working the way it’s supposed to.@sjpkarter wrote:
Question is, what’s the best way to:
– …protect it from oil, gas, various other fluids like beer, grime, etc.? Sparco site says Scotchguard it – really? What about this Molecule Labs “Protector” stuff (http://www.moleculelabs.com/Products.html) or other products?Take it off when you work on the kart. I’ve never used a treatment. The other important thing is to always run a chain guard and keep the spinning parts clean. The easiest way to get your suit dirty while driving is to have oil flying off the axle/chain onto your suit. Also, any dirt/grime/grease in your seat will end up on your suit. Put a rag in the bottom if you like to put parts and tools in the seat when working on the kart, and clean the inside of the seat regularly.
@sjpkarter wrote:
– …clean it: Sparco site says cold hand wash (or in delicate cycle, cold) with soap like Woolite, air dry (inside out for faster drying)? How often, in general?
Whenever it’s dirty/sweaty. In general, every race weekend. Sometimes after every day of driving. I’ve always just used a machine for both washing and drying. Kart suits are made of a burly fabric, so I’ve never seen the need to treat them like a delicate wool or whatever.
@sjpkarter wrote:
– What about shrinkage when washing/drying? This suit seems just about exactly right as is, don’t need no steenking shrinkage.
I’ve never had a suit shrink.
@sjpkarter wrote:
– For kart seats with mounting hardware exposed on the driver’s side, what kind of wear and tear on the suit can I expect? How best to protect against that?
I’ve never seen much of any wear on the suit directly from the mounting hardware.
@Doug Welch wrote:
I just checked my dealer lists and I have at least 4 dealers that have some version of kart works in their name. The other common one is Extreme.
“Kartsports” is really common too.
And please, no more three letter acronyms in kart business names!All axle bearings are not constructed the same, but the size is the same. So you can buy them from anybody.
They are very easy to remove. You can’t press them out because they have a spherical outer radius. When you remove the bearing carrier from the kart and loosen the pinch bolt that holds the bearing, you’ll notice there are two notches in the cassette, as you can see here:
Simply rotate the bearing until you can remove it through those notches.
I’m not sure if the dual seal program applies to DD2 (I think it does), but the cylinder exchange program definitely does. It’s quite unlikely that a DD2 cylinder would be out of spec, but the program does apply.
I just realized I missed a couple of your questions in your original post.
Parts – if you get an ICC, the parts will have to come through a dealer for whatever particular engine you have. ICC parts are pricey. If you buy a stock Honda, you can get parts from any Honda motorcycle dealer in the country, and there are hundreds of them. Honda parts are cheap. If you get a Rotax (DD2 or TaG), you’ll have to buy parts from a Rotax dealer. Rotax parts are pricey, but you generally don’t have to replace them often.
Starting a shifter – there are no starter mechanisms available or legal for the 6-speed karts. You have to bump start them. Usually this means having somebody push you. You can do it by yourself (take off at a run pushing the kart, then jump into the seat and start it) but that’s not easy to do (worth practicing in case you need to do it during a race though). The best method to push start a kart if you don’t have a buddy with you is to ask somebody else in the pits nicely 😉
The DD2 is easier because it has an electric starter on board just like a TaG kart.@RainMan303 wrote:
@Jeff Welch wrote:
[…] I would strongly recommend the Stock Honda class.
Thanks – you have confirmed my gut feeling. I am a huge fan of KISS classes – Keep It Stock, Stupid – my extensive and expensive mods to my Honda CBR600 taught me a lesson on that one.
Thanks for taking time to demystify this stuff. Just out of curiosity: what do ICC and DD2 stand for? I can make a wild guess that DD2 stands for Direct Drive 2-speed, but ICC….?
Good question. ICC stands for Intercontinental C, which is the European name for the class. For our purposes here in the US, ICC refers to any of the 125cc, 6-speed engines manufactured by a variety of Italian companies specifically for karting purposes. A “moto” engine, on the other hand, refers to any 125cc, 6-speed engine that was originally built for dirt bikes that has been adapted for use on a kart. The Honda CR125 is by far the most common moto engine. Again, despite being built specifically for karting, ICC engines are subject to some major disadvantages as I discussed above. The Europeans apparently don’t really mind rebuilding their engines constantly, which is why they are willing to sacrifice longevity for power. The trend in the US has been to increase longevity at perhaps at a slight power penalty.
If you’re looking for used karts, you’ll probably come across “built moto” engines. These are the engines we used to run before ICC was introduced to the US. Essentially, they are heavily modified moto engines (again, usually Hondas, but there are a few Yamahas and TMs out there). They can be raced today in the same class as the ICC engines, but are generally not competitive and usually suffer the same reliability issues. The Stock Honda class was designed to address the reliability issues of both the ICC and built moto packages, and in my opinion, has done so very admirably.
You might actually be right on the DD2 standing for Direct Drive 2, but it’s not referred to as such in the US. It’s also not really accurate – the DD2, although it has no chain, is not direct drive. It has a centrifugal clutch, which allows the engine to run at an idle without the kart moving. As soon as the engine RPMs increase to a certain point (ie, when you push on the gas), the clutch engages and the kart begins to move. In a true “direct drive” vehicle, the engine cannot run unless the kart is moving.
Welcome to karting!
There are four 6-speed shifter classes in Colorado:
125 Shifter – ICC and built moto engines, age 16+
125 Shifter Masters – ICC and built moto, age 35+
Stock Honda – stock Honda engines only, age 16+
Stock Honda Masters – stock Honda engines only, age 35+If you’re dead set on getting a shifter, I would strongly recommend the Stock Honda class. This is for two main reasons: 1) the reliability, cost, and performance are very good and 2) it is a very rapidly growing class, whereas ICC shifter classes are shrinking. ICC is your other main option for a 6-speed shifter (there are also some older built moto engines out there, but they aren’t competitive against the ICCs). These engines require substantially more maintenance than a stock Honda and are therefore generally more expensive to run.
Another option you should definitely consider is the Rotax DD2. It is a 125cc, 2-speed engine package, and depending on the track, is either slightly slower than or slightly faster than a stock Honda package. Cost is similar. However, the DD2 requires much less maintenance than pretty much any other engine package currently used in karting (and we mostly use pretty reliable engines these days). It has all the long life characteristics of the Rotax TaG engine but does not have a chain (the axle runs through the engine and is driven using a splined hub), which is the primary maintenance point on a TaG. The other big difference is in a full-fledged 6-speed shifter, the ride is fairly brutal because of the ridiculous amount of torque. In a DD2, the power goes down very smoothly, which translates to a lot less abuse on your body. I’m not kidding when I say I’ve come off the track in my shifter with half a dozen severe bruises. That won’t happen in a DD2. Other positives to the DD2 include a sealed engine that can only be worked on by authorized service centers, which prevents people from cheating, and a 1 year warranty on the engine. Rotax engines are the only engines in karting that have a warranty!
And then, of course, there’s TaG. If you want to truly learn how to drive, get a TaG. A shifter can mask a lot of bad habits. If you slide sideways a little in a shifter, you can simply drop a gear and get most of it back. Maybe one guy will pass you. If you slide it in a TaG, five guys will pass you. The ability to drive smoothly is certainly important in a shifter as well (and all the fastest guys in shifters are very smooth drivers), but it’s much more difficult to learn when you have all that torque at your disposal to mask driving mistakes. TaG karts are less expensive than a shifter and quite reliable, so they’re always a solid option.
Please feel free to give us a call at the shop at 303-781-7829. We’re more than happy to answer any questions you have.
(My family owns Shockwave Karting. We’re the largest American manufacturer of karting components, have our own chassis line, and are one of the Rotax service centers for Colorado.)@D fresh wrote:
Looks like I’ll have some work to do.
Everything off? We’re talking flywheel, electonics, carb, radiator and hoses, stripped to everything outside of the seal, right?
Correct, Doug. Everything outside of the seal, stripped and cleaned.
To my knowledge, Greg intends to have the seminar tomorrow as planned. I’m sure he will correct me if anything is different.
Unfortunately, weather is an reality we can’t control. Next weekend Greg will hopefully be at the Gatorz race in Las Vegas, and after that, as Rich pointed out there is a race here in CO every weekend until April 26. That weekend is the Stars race at Miller, and the first weekend of May is another race. So we’d be looking at Mid-May at best to reschedule.
Perhaps the biggest issue is not everyone reads this site regularly, and it would be very difficult for us to get the word of cancellation/postponement out to everyone that is planning to come. We learned this when we moved the start time of the last seminar!
The weather tomorrow for Dacono is “A slight chance of rain and snow showers after noon. Mostly cloudy, with a high near 44. North northwest wind between 5 and 13 mph. Chance of precipitation is 20%.” So it may be cold but it probably won’t rain.
If you only want to come to the classroom portion, that’s fine. However, I would greatly encourage everyone to brave the cold and come on out – you will definitely learn a lot!
