[thefrush]

So a couple of years back, my cousin, who is a big fan of motorcycles and dirt bikes, bought a 125cc shifter kart. It was a Track Magic, and it had its fair share of issues, namely low compression, that prevented it from idling and made it very difficult to start up. So it was always a PITA to take out and drive because it was so hard to get going and keep going. If you stalled it, you were screwed. But it was still a MAJOR blast. The acceleration is what I remember most, with a 0-60 rated at around 3.5 seconds, the supercar performance only a few inches off of the ground was exhilirating. Its braking and handling were breathtaking as well, and after just a couple of 10-minute sessions, it would leave you feeling like you had been in a tumble dryer, yet with the satisfaction that you had just done something under the covers.

Much to my dismay he sold it. I've always missed it and wondered when the next time I would be able to experience one again would be. Well, he called me today with the exciting news that he bought another one, and this one is even better than the last. It's a 2002 TonyKart shifter with a steering wheel mounted computer that tracks temps, RPM, lap times, etc... It has a Vortex ICC dedicated shifter motor that should move a good bit faster than the dirt bike motor we had on the last one. The only issue with it is something in the brake system that causes them to lose pressure, there is no fluid loss, but air apparently seeps in somewhere. So we have to fix that. Once we track that down it will be a total BLAST. One thing I never got to do with the last one was take it to the dedicated kart track at Sears Point, so I look forward to being able to do that with the new one. Can't wait!

The track at Sears Point:

Me on the old kart:

 

[JCMRacing #37]

I've been trying to obtain one for about six months now. This is exactly why! Great description Frushy!

after just a couple of 10-minute sessions, it would leave you feeling like you had been in a tumble dryer, yet with the satisfaction that you had just done something under the covers.

 

[belacyrf]

Nice!!!! Shifters are crazy fast, and thank the lord for front brakes hehe

Yea that Vortex should be nice! I need to get back out there

 

[seanmc]

NICE.

I keep thinking about getting back into it, and have been obsessively checking the ekn classifieds for a TaG kart lately...

Good luck with 'er, and remember to thank your lucky stars that you live near a good sprint scene :thumbup:

 

[thefrush]

Kart is nearing track-readiness. When we got it, it showed some ugly signs, no brakes whatsoever, a running leak at the clutch pack, and we had to diagnose each issue. So we started with bleeding the brakes, and got some pressure in the system, which got us pad movement up front, but only on one side of each caliper, and the other side was leaking around the piston. So we disassembled each caliper, and assessed that the seals were fine, but that in each caliper, the outside piston was seized, causing a high pressure issue in the other piston, forcing the leak. After cleaning everything thoroughly, and reassembling the calipers, the front brakes were good to go. :thumbup:

The next issue we checked out was the leak at the clutch pack. We weren't sure what to expect as we took the clutch plates off, but it turned out to be very minor. The inside housing, don't know the technical name for it, but it sort of acts like a flywheel, transferring the power from the clutch to the transmission. That plate was very loose, in fact, each of the 6 allen heads were only finger tight, so all of the play the plate had on the shaft was causing the leak. Tightened those up, good to go.

We moved on to the rear brake, which, after bleeding the system had pad movement on both sides, but it wasn't very strong and I could still rotate the axle manually. We also observed a leak around one of the pistons. So we disassembled, and my cousin evaluated that perhaps the pistons were moving too much, which would cause the leak, and also explain why we weren't getting enough pressure out of the pads. So this weekend we are going to shim the pistons, and hope that does the trick. Then Sears Point, here we come! :thumbup:

 

[JCMRacing #37]

Then Sears Point, here we come! :thumbup:

Can I come? :lol:

 

[brads03zx3]

I have a feeling you disassembled the caliper, and not the rotor??? I have tackled a bit of brake engineering this week. It is really tough to design a brake system for a car I have no information about. Sorry, back on topic :thumbup:

 

[thefrush]

Yes, caliper!

The way I see it, I'd rather have more front brake than rear, but with the shims, hopefully the rear brake will actually be useable, and not leak. Then we can adjust pressure from the master cylinder.

 

[Nickgt40]

So what size are the disks? And how many cc's is the motor on this new one?

 

[thefrush]

I believe the fronts are 160mm, and the rear is 200mm. The motor is a 125cc.

 

[wallygator]

You gonna tape it blue too?

 

[thefrush]

:lol: Nah, no tape on this one!

Rear brakes are good to go thanks to some shims. Kart is officially track-ready. We are going to do some research this week on fuel mixing and tire pressures, and also figure out how to transport everything (kart, kart stand, fuel, tools, gear, etc) and hopefully take it up for the first time between Christmas and New Years.

 

[brads03zx3]

:lol: Nah, no tape on this one!

Rear brakes are good to go thanks to some shims. Kart is officially track-ready. We are going to do some research this week on fuel mixing and tire pressures, and also figure out how to transport everything (kart, kart stand, fuel, tools, gear, etc) and hopefully take it up for the first time between Christmas and New Years.

We could throw it on the track at THill for the 24 hours of lemons...though the driver would have to have a huge set to duke it out with inexperience amateurs in crappy smoke-belching cars

 

[thefrush]

I wouldn't take this thing anywhere near Lemons. :lol: Plus, I'll be too busy dukin' it out inside our oversized go-kart. :arr:

 

[thefrush]

Ohhhhhhh yes. Took it up to Sears Point today. Was a long day, quite reminiscent of a normal track day for me, LOTS OF TRACKSIDE WORK before getting to take it out! :lol: First we had to figure out our jetting so we didn't roast the engine, so we went down to a kart shop at Infineon and asked, he gave us a set-up to try. We got the kart going and let it start warming up, and then ran into issue after issue, loose clutchpack, improperly reassembled clutchpack, etc.

Finally got it on track, my cousin took it out for some laps, came in and told me to get in. Unfortunately our jetting was far too rich and the engine would bog in the mid-range 7-8K RPM. Then at 8K RPM you'd instantly get full power and have your head ripped off your neck. Made coming out of corners very difficult as you couldn't find the powerband, was like a lightswitch. So we decided to put in a smaller main jet to lean it out. Much improved, still a bit fat in the midrange, but much easier to avoid. The thing drove great, and for a first day in a new (used) kart, it went quite well. We learned a lot and know what to do next time. We have some adjustments to make to the jetting and tire pressures to get the kart dialed in. By my last session I was laying into big powerslides through every corner. These things are stupid fast. Impossible to explain, you just gotta do it.

These are all of my cousin driving, I didn't want him using my brand new Christmas present Nikon D40 to take pics of me, so I am on his camera.

 

[JCMRacing #37]

Shibby!! Frushy, I need to move to NorCal and become your best friend. :evilgrin:

 

[sleeperlove]

definitely wicked

 

[thefrush]

Here are pics from my cousin's camera:

My cousin:

Me:

Comin' down the main straight reachin' for 6th...

My cousin holdin' off some pressure:

 

[carlfreddy]

I am jealous.

Nothing like muscling around something with the power/weight ratio of an F1 car.