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Here are the release instructions from the SKF ConCentra PDF (easily found via search engine).

Lightly tap the sleeve edge on the mounting collar side of the bearing until the locking system releases the shaft. As an alternative, tap on the bearing inner ring side face on the side opposite the collar.

I’ve just installed mine and have not yet needed to either re-grease or release/remove, but when I do, I’ll use a plastic hammer or a piece of PVC with a steel hammer to protect the bearings. “Lightly tap” means these should free easily.

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That did it!
Thanks for the quick reply.

Squeezing the collet lets the entire inner insert come out.
Then I could insert the bearing into the cassette and replace all the inner bits.

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I ordered the ConCentra bearings, but they don’t fit (out of the box) into my cassettes. The collar that tightens adds too much width such that one cannot insert the bearings perpendicular to the cassette.

One either needs different cassettes or there’s a trick to removing the collar.
I’ve sifted through the SKF docs on the ConCentra and can’t find any trick to remove the collar.

Do I have to order new/different cassettes?

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Have to agree with Steen here. It’s probably not worth putting too much $$$ into a blown clone. ;)

Buying parts is typically more expensive than buying complete units, so starting with a decent used motor and a “freshening” will likely cost less in the end.

You can send your PRD into any builder for examination and repair estimate, and right out of the gate you’re hit with the expense of shipping.
You could try Comet or LAD or P1 or Woltjer or any of the many engine builders.

Call first and ask about their PRD experience.

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Price?
Contact info?

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Only a minimum amount of hair is allowed to be tucked inside the helmet. I can’t recall the exact amount, but its a small amount. Too much hair tucked inside the helmet reduces the efficacy of the helmet’s ability to absorb energy in an impact. I’m certain I’ve seen written regulations but I can remember where.

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That’s kind of my point in asking.

Where? There are no “kart shops” in New Jersey.
I’m looking for a full service shop, with various seats, seat sizes in stock, who can then help with proper fit.

It’s tough to measure a kid properly and order a seat online. I’d like to find a shop where he can “try on” various seats and find one that fits perfect, with the advice from someone who’s done it many many times.

In theory I’d be willing to drive to Comet in Ind, but I’d certainly prefer to find someone closer.

Specific “kart shop” suggestions please….

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In NJ.
Local, but regional when and if possible.

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She’s been around the whole track checking tire pressures kiwi style.

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Looks like a good, thorough book, but it’s currently sold out on web site.

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I use lots of brake cleaner; I buy it by the case when it’s on sale.
Careful of paint though, don’t let it sit long on painted surfaces.
Kerosene, isopropyl alcohol, camp fuel, all have a low flash point and are good at loosening greasy build up. Get a good stiff brush (home depot paint dept) to help scrub with kerosene. NEVER USE WATER! No where, no place, nada!

Buy bags of microfibre cloths from your local costco, sams club, etc.
Wipe and clean. As you go you should be inspecting for loose parts, nuts, bolt, cracks, etc. I disassemble to a reasonable point, clean and reassemble nearly after every race weekend.

It’s a good way to catch problems early and get to know how the kart looks when everything is in its place. It makes it much easier to spot issues once you’ve come to know your vehicle centimeter by centimeter.
BTW: This can work well on the spouse too.

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I’m sure that was the original plan, but reality hit them hard, just like Atlantic City. Millville is a slum and their largest industry is prisons, with three of them. Since the reorg they’re a little more realistic about where their money is going to come from. Most of the Porsches and BMWs are because the PCA and BMW car clubs rent the tracks for driver education days.
I belong to both and have never bothered going. Just joined SCCA and might try it out next year.

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That’s a chicken and egg problem. My son started with arrive and drive and has now successfully completed his 1st year of racing. We’ve all got to start somewhere and those that get bitten, get it bad. A racetrack, presumably managed by racers would want to encourage racing and leave arrive and drive as a portal for newbies. Again, I hope this was just talk and not true. Doesn’t matter much as we only get to race one or two races a year there anyway because of the various club’s screwed up class structures. Can’t buy only one motor and run all the clubs competitively.
Parilla, Rotax and PRD (TaG) seem to stepped on their own toes promoting their products.

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I didn’t mean to imply he was offering them for sale, just curious in general.
I have a late 90’s Margay A/C Synchro, a new ’13 Margay Brava, an ’07 Merlin cadet and a 900mm PTK CRG. They’re all for my son.

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I can’t say for sure, but one of the tricks I learned was to test my compression once, then again after squirting some plain old 30 wt motor oil in through the plug hole and testing again.

If the compression jumps up, then the oil is helping the ring seal and yes, you’re not getting a good seal between piston and ring.

Aside from that, there are too many unknown variables.
I’d suggest buying a second motor anyway as they vary quite a bit from one casting to another.
You never know when you’re going to need a “B” motor, just in case ;)

 

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Order a ring from one of the respectable online dealers, call if you need to talk with them to make sure you’re getting the correct ring.

Usually one can get a ring .1 mm larger ring than the piston, so if for example your piston was oversized 0.5 to 52.50 mm, then you’d get a 52.60 mm ring and file equally from the ring ends until it fits to the gap spec ( .1 mm equals almost .004 of an inch).

 

 

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Morgan,
Thanks for that link, excellent reasoning!
And static measuring is consistent. Think of all the variables taken out of the equation when making static measurement.
Then one can increase/decrease relative to baseline as needed.

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What should be my ring gap, with a feeler gauge at the ends? 

Install the ring in the cylinder and push it with the piston towards the upper end. The “gold ring” end gap clearance is in the .008 to .014 range. Yes, you check with feeler gauges, but don’t use shit tools from Sears, buy yourself a decent set of Starrett feeler gauges. They also make great 12″ finger feeler gauges that are good for checking piston to cylinder clearance, taper, etc.

Also make sure you install the ring with the “T” for top on the top side :)

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Speaking of NJMP, I heard a rumor at the track this past weekend that there will be no club racing at NJMP in 2015. Granted it’s just a rumor, but I can see them being tired of the hassle and noise from racers for what amounts to lunch money for NJMP.
I certainly hope it ain’t true as it’s a beautiful track. If anything they should be working to encourage *more* racing, less arrive and drive.

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Google is your friend, check Amazon too

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Screw’em all. We’re running a KT-100 and we’re sticking with it until my son is 15. Hopefully by then he can get his SCCA license.

 

Easiest, cheapest, best way to vote with wallet; KT-100

 

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Could you please submit a link to one of those ads? I think real-time telemetry would be outstanding!

It’s not required, but not having it simply slows down the process of waiting til the end of a race, downloading data, examining the data and trying to make adjustments (possibly) based on the data.

Presently the USB data key is a major hassle. I have to other work to do like check chain, adjust chassis, change axles, etc. No time to play with PC.

All I really want is the wireless, real-time to the PC so I don’t have to connect the kart to the PC. Then, I can look at the data during the race and plan any adjustments I foresee, pending confirmation with driver.

This is the future of all motor sports, right down to karting.

If you want to blame anything for the rising costs of karting, blame Rotax and TaG.
As well as all the class incompatibilities. If you want to run in more than one series, there’s a very good chance you need more than one motor.

 

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Exhaust Gas Temp probe.

 

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Castor is “old school”

In this day and age castor has no benefit over high quality, 100% synthetic oil.

Especially for a weekend warrior. Synthetic has little to no carbon buildup, less carbon cleaning. Castor is a vegetable oil, and left sitting on a shelf too long will go rancid, just like any other vegetable oil, while synthetic is fine sitting for years.

Motul 800 2T is great stuff.

For weekend warrior stuff, track days and practice, I see many people using pump fuel.
Why waste the money, but make sure you don’t have any detonation or it’ll cost you later.

The VP is inexpensive insurance; no ethanol, and the lead does lubricate, so if you can afford it and have easy access to it, why not spend a  little extra?

 

 

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Most people ask me how fast he goes, not about the kart’s HP.

Running the KT100 with Jr Sportsman restricted intake (races against C-80) I’ve seen my son hit 60MPH on a long straight. We probably could have geared for more speed but had to balance gearing for corner exit power with straightaway speed.

Horsepower is relative, same dyno, same day different readings.
I’m guessing that 8HP is a tad high, but close to a max in this class (C-80)
Racestudio’s “engine analysis” says we’re making close to 6HP calculating from change in speed (Power = Work/Time)

Rotax, next year :)

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