06/12/02 Another kart outing. A very hot day, about 90 F. Was going great until the piston ring broke, chewing up the head, piston and bore. The video sums up the experience. Now have to buy new parts and rebuild the motor. This is after about 2.5 hours running time. But then if my M Coupe was tuned this tightly it would be putting out approximately 1,000 horsepower.

Also looks like we're going to need a new radiator - the current one had cracked from vibration and the fixes applied by the seller were very temporary in effect. All part of the fun, I suppose :)

06/18/02 Took the cylinder, piston and head to a local kart specialist (Mike Gent of Shark Shifter). The verdict: head and piston totally shot ($65 and $85 for replacments, respectively). The cylinder can be saved for $200. I've decided to get it bored out 2mm over in the process, which will give me more power and torque. It is not legal for racing, but I don't intend to do any racing with it anyway. Also need a new radiator at $175, and a few miscellaneous bits and pieces. Also, the bottom end will need to come apart for inspection. If any problems are discovered it will need a few more parts. Having someone to split the bills with definitely helps!

7/10/02 Picked up the finished kart motor. Including a new radiator, the total comes to $772. Not too bad, especially since only half of it is mine. For blowing up a race motor it's actually a bargain. So from now on it gets 110 octane race gas only, and hopefully a longer happier life. Now I have to put the motor and radiator back in the kart, fill the vital fluids, and do some break-in before hitting the track again. The weather has been way too hot recently anyway, and I've been busy with other car-related stuff, so I guess it all works out.

7/17/02 Finally had a couple hours to spend on the kart. Got the motor mounted back in the frame and routed a few wires and cables. Also changed to a bigger jet on the carb to accommodate the new displacement (with a 2mm overbore it is now 130 cc instead of 125).

Still need to mount the new radiator and fire it up. It was recommended that we run the kart on race gas, so I went and bought some 100 octane at $6.50 per gallon. I bought unleaded because I have tried mixing race gas into the Elise and it SEEMED to run smoother, so I decided to keep doing that. For the kart specifically we can buy 110 octane leaded at the track.

In the not-so-good news, I was inspecting the kart components and besides needing a new air filter it also seems to need a new axle, because the existing one has a massive crack in it.

This is certainly proving educational. Gives me some idea of what people who run REAL race cars go through. It's good to know there are crazier people in this world than I :)

07/18/02 Finished putting the motor and radiator in the kart, fired it up. It runs although it doesn't idle - will have to investigate what the adjustment should be.

For break-in I have to heat-cycle the motor a few times. Start it up, let it warm up, then shut it down and let it cool all the way. Did it twice so far, will need to do it maybe at least once more, maybe twice. Did some further inspecting and determined that the rear brake rotor has lots of cracks in it (and a chunk missing) and is basically about to disintegrate. We got a spare one with the kart but I don't think it's in any better shape. So add a rotor to the list of things to get. Really makes me wonder if it would have been better to just buy a brand-new one... ? Ah well. It's an experience.

7/22/02 Procured the new axle, a new air filter, new brake rotor, some muffler packing and miscellaneous bits. Good thing kart parts are relatively cheap, with the total coming to just over $200. The rebuilt motor with the new filter and freshly stuffed muffler is now fully broken-in and looking ready to go...

Just as soon as I replace the axle that is. The old brake rotor is in pretty bad shape.

Almost all the holes have cracks at them. I wonder if the drilling is done to sell more brake rotors - the holes don't really lighten the rotor very much, they don't do a whole lot for cooling, but make the rotors disintegrate in much shorter time. Oh, they do look pretty though - which I guess also helps sell more rotors? The new rotor I got is not drilled, so perhaps it will last a bit longer.

A somewhat humorous response from my kart guru on the lack of idling - "i don't like them to idle, if you let off the throttle the motor should die". Makes sense - this is not a part-throttle sport :)

7/31/02 Upon pulling out the old cracked axle (no trivial task) I discovered that the bearings need replacing as well. There goes another $105, for a total of $1,000 or so to get the thing back in operation. It's been sitting in the garage for six weeks now, with the summer ticking away... :(

So I went and got the bearings, got everything installed and ready to run, hoping for tomorrow. Called my karting partner only to find out that the truck that we use to transport the thing is in southern Oregon. I guess we'll have to wait till next Tuesday before we can use this beast. I sure hope things refrain from breaking for a while! For the moment, all is nice clean and shiny...

8/08/02 Ugh. Finally took the kart out. Beautiful day, too. The good news is that the motor runs great. There are gobs of torque everywhere, and you can dial in just the right amount of sideways drift with the right foot. Shifting is improved too. First session, lots of fun. Then my kart partner gets in and for a while it looks like he's having a blast, sliding around turns and blasting down the staight at downright scary velocities. Then a problem. He pulls in and says the karts doesn't shift. I take it out and realize that the actual problem is a very badly slipping cluch. I look at the cable and realize that the way I routed it causes it to bind. Loosen things up, reroute and out again - still slipping. We pack it up for the day and drop by the worshop of Mike Gent, the kart guru. He pops the clutch out and it measures out OK. Then he asks about the fluid... I had put in synthetic ATF, the best stuff. Too good, it turns out. Causes the wet clutch to slip. Of course the problem is that now the clutch disk fibers are soaked with the stuff and we need a new clutch. No big deal, 20 minutes tops... Then I notice that the sprocket key came out and tore up our brand-new axle. So we need another one. At this point I got quite discouraged and didn't want to go through the same routine again, so we just left the kart there for Mike to fix it. We'll pick it up next week. So after 2 months messing with it and missing most of the summer, we get it out on the track and break it within the first 20 minutes, without pushing too hard. It's basically my screw-ups. Live and learn I guess (note to self: better LEARN).

08/22/02 Well, got the kart back, another $330 later. Took it out and it finally ran well. Of course not entirely without incident - 5 minutes into the first session the tail end started stepping out like crazy. I saved it on a few turns and decided to come in (one lesson learned - if the kart starts acting weird, bring it in immediately). Turns out the shop didn't tighten the gearbox oil filler cap, and it came out, spilling oil all over the track. Right down the racing line. So we spent 45 minutes mopping up the track, then looking in vain for the cap. After a while, my kart partner went to a motorcycle shop to buy another cap and I went about refilling the gearbox oil and then looking for the original one again. Another 45 minutes later I found it! So now we have two caps.

Ran several sessions. The kart is a really brutal machine and wears you out quickly. 30 minutes of track time and I'm done. It's been so long since we ran last that my times didn't improve any, still hovering around 40 seconds give or take one.

Overall the experience so far has been quite different from what we had anticipated going into it. During the entire summer we took the kart out 5 times so far, and it has cost around $1500 in maintenance. Which translates to something like $5 per minute. Of course we have learned a lot, and it's great experience for my other projects - so I look at it as tuition in the school of motorsport reality. And as such it's pretty cheap :)

09/03/02 Now THIS is more like it! Excellent day. The weather was perfect (not too hot, not too cool, sunny). The kart ran well and nothing fell off or broke. Although the shifting was a bit weird... The track has been modified with an addition of an extra section which is very bumpy. Would be more fun if it were smoother... We ran several sessions, both of us in the 56 second range. Working on relaxing and not having a death grip on the wheel - and succeeding, little by little. Although I will still have very bruised ribs tomorrow. Then at the end I decided to do a couple of hot laps just to push my personal envelope. Turns out you can toss the kart right into turns, get the back out, then with power transfer the weight back there and make it stick! Whewww... Shaved 3 seconds off the lap time just like that. A brief video summary illustrates... but doesn't do it justice, really. It's WILD. The pictures below are of my karting partner in action.

I think the kart is set up a bit too soft, since our rear tires are wearing on the inside edges. Next time we'll bring the torsion bar and see what kind of difference it makes. Once pushed, this is truly a mind-bending machine.