[William Martin]

Bore size (std) is 52.4 for the KPV, maybe just a way to use a worn-out cylinder that is too big for a KPV piston now? I suspect it won’t run very well, the port timing is altered a bit by those bottom spacers…not sure it is a big deal, probably not a race legal cylinder anyway, but I’m not an “expert”, don’t even play one on tv…

 

[William Martin]

I don’t know, depends on what kind of lap time you can get on the stand…but I doubt it will work, those little wheels aren’t very grippy :-)

 

[William Martin]

Me too! (no, not THAT me too) :-) Any guess when eknclassic.com will come back to life?

Thanks,

Bill Martin

[William Martin]

David,

while you are looking at this, I wanted to mention that some time ago I noticed broken links on the archive site. Probably too late to do anything about it now…just fyi.

 

[William Martin]

Wow, that’s a strange one. Just out of curiosity, has it always behaved this way, or is it a recent change? It would be really good if you could borrow another carb & swap the whole thing out to see if the problem goes away. Just hate to go buying a new carb without that one sanity check!

 

[William Martin]

Not familiar with what “typical” jetting is for that engine/carb combo, but if the plug looks good I wouldn’t change float height or main jet. It may be that your pilot jet is too big, and the air bypass has to be adjusted way out to make it idle. The fix for that is a smaller pilot jet and turn in the air screw a bit. I’m just going on a prior experience with a Honda shifter that developed a terrible bog when going full throttle. What had happened was the air screw had vibrated loose to where it was about to fall out… as soon as I put a new O-ring on the jet and set it back to where it was happy before, all was well with throttle response. You can easily try turning in the air screw, don’t worry about good idle, just keep it turning fast enough to not stall while you do your search for correct air screw setting. The important thing here is to stay on the safe side with jetting changes…go slowly!

Bill

ps: just fyi, if it runs good at full throttle, it isn’t weak ignition parts.

[William Martin]

Might try turning in the air screw a bit. Does it gag on the stand if you give it full throttle from idle? If so, turn the air screw in about a 1/4 turn and try again, repeat until you get decent throttle response. Hope this is useful!

Bill

[William Martin]

Did you check the ring end gap with the ring in the cylinder by itself, no piston? It looks like you may have snagged the ring in the exhaust port & broke off a piece. I see some sign of trauma just above the exhaust port opening in that cylinder…I always worry about that a little bit with these oval port monsters, there is no center bridge to keep the ring out of the port. I know it works really well “most of the time”, but if the ring end gap is not there, the ring has to expand somewhere when it gets hot.

Bill

[William Martin]

Wow, that’s pretty messed up! It looks like some little bit of metal or something else hard got in there and danced around for a while. I’ve had that happen before, it was a small piece of the big end bearing cage that did the deed. Not so lucky with the cylinder though… could you have swallowed a tiny rock thrown up from the track surface? Doesn’t seem likely, with the filter inside the airbox. Take a close look at the ring…anything missing? Good luck, hope you figure it out before next rebuild hits the track!

Bill

[William Martin]

Is it equally hard to turn in both right & left direction with weight in the kart? One thing you might try is taking Sniper readings with the kart on the ground & you in the seat. There should be “small changes” from the readings taken on the stand, but nothing major. If you see a major change, something is likely broken, under the powder coat so you can’t find it…without magnaflux inspection. The usual suspects are cracked welds, which may be findable with a good eye & weight in the seat to make them move around a bit. Good luck!

Bill

ps: when you drove it, what did the front tires look like afterward?

[William Martin]

Finally! This is a product that just had to happen, it’s such a natural way to get a high quality display without having to spend big bucks for it…btw, what IS the projected price?

 

[William Martin]

Can’t help you with the gears, I’m long ago sold out. If you ever want a belt tension gauge, I have one from Pfieffer(sp?) that is in perfect condition. No idea what it’s worth, make an offer if you want.

-Bill

[William Martin]

180 doesn’t sound too heavy for a 30/32 tube chassis. Seems odd that it would be sagging…could it be cracked somewhere hard to see?

 

[William Martin]

It’s probably bigger than just a lame web site, but I agree, that web site is/was lame, Comet is much better organised.

 

[William Martin]

Why would mapping have to be sealed? Is your carb sealed now? Would that be a good thing?

[William Martin]

Not about being afraid of change, just not wanting some bureaucrat dictating the terms. I would personally love to see a good fuel injection package for karts, but don’t think I want it designed by a lawyer. Cost IS a factor here, mass market emissions specs could well kill the whole thing.

-bill

 

[William Martin]

Hmm, I sure hope politicians/regulators don’t start considering karts as “off-road vehicles”, as opposed to pure racing vehicles. Please don’t encourage that line of thought! :-) It could be very dangerous to the future of karting.

-bill

[William Martin]

Don’t know, you can do it now if you want to spend the money. See: <http://www.ecotrons.com/products/2_stroke_small_engine_fuel_injection_kit/&gt;

Of course, unless it’s available to all as a bolt on kit, it’ll never see approval from any sanctioning body…

This is not a “clean” EFI either, doesn’t get rid of the intake/exhaust cross flow issue.

-bill

[William Martin]

Not an ItalKart expert, but some general thoughts:

I wouldn’t worry about the fixed vs floating rotor, fixed works just fine as long as you keep it aligned and check that your caliper is working correctly, same motion on both sides. Personally , I think the floating rotor is just a band-aid for people that can’t make good calipers…

The front hubs will be a bit stiffer & may feel better on turn-in than the direct mount wheels, given same spindle diameter. If it’s handling well as is, why change it? Experiment, of course, is the ultimate answer generator. I would stay with the 40mm rear axle, as there don’t seem to be sealed bearings for the 50mm size, and sealed lasts a lot longer than those shielded dirt-eaters ever will. Even if you were racing I’d still recommend sealed bearings all around, front & back.

[William Martin]

Spencer,

Price is certainly an issue, but it is a “one-time” issue vs. recurring maintenance costs. For some, it will lock them out, which is unfortunate, as karting is not supposed to be that “exclusive”, at least not in my opinion. Long term though, I suspect the bigger engine is the better answer, as the -ES engines give up some performance to the plain KZ, that larger bearing has more friction loss & eats power. So if the motive for leaving stock honda is performance…as I think I saw earlier in this thread, the 175cc wins out.

[William Martin]

Stock Honda isn’t exactly consistent with KZ class…and if you want to keep the user-friendly nature of Stock Honda, it makes perfect sense to go with a larger displacement, less highly tuned engine than the KZ family. Just as much performance, lasts longer. It won’t sound as cool though…

 

[William Martin]

There is a snap ring holding the bearing in place. Unless you be Godzilla, you probably can’t pull hard enough to pop it out!

 

[William Martin]

“not hit anything”? now really, where would you vendors be if that ever happened… :-)

Bill

[William Martin]

Dave, I don’t know about the RR brand axle, but just be aware that if you go to a different stiffness axle, it will change the way your kart handles. That might be good or bad, depending on where you are now…

 

[William Martin]

Each horizontal grid line is 2mm camber per side. Don’t know why you would measure any other way than “per side” :-) since the zero reference is the ground. Must be that flat earth society thing…

 

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