[Alan Sheidler]

There are a lot of options, many of which will meet some track requirements.

If yours is loud, and it wasn’t before, repacking it may help a lot.  I would only buy one which could be disassembled and repacked (may have to drill and replace rivets)

Recognize that quite a bit of the noise you hear is likely coming from the intake end of the motor.  That will be true if you have an open air filter. Unless you are running a noise-reducing airbox, there are ways to muffle the intake pulse sounds, primarily by using a surround which is only open on the seat side or the back.

Good luck!

[Alan Sheidler]

Assuming that you are running Stock Moto, and not going for the front/win in larger events, of course you can just order one from Honda.  Many online dealerships will get you one at a competitive price.

Understand, however, that you will have additional work to do.  The most important (and risky) of those is to install and shape the plugs for the powervalves.  Verify bore, get the right piston/ring, new gaskets….

How many of those items are included with the Swedetech item, and do you place any value on your own time to do the prep work?

 

All considerations to make before deciding.

[Alan Sheidler]

Not silly.

I’d go for something like this.  eBay is where I bought mine.

http://www.ebay.com/itm/1998-1999-Honda-CR125R-Factory-Service-Manual-61KZ451-/262899443827?hash=item3d36072873:g:P-8AAOSwol5YzEZl&vxp=mtr

[Alan Sheidler]

For 3 grand total, you won’t get anything that will be anywhere near competitive, or that won’t be in need of a ton of work and additional $.

I’d expect to spend at that much, or at least $2500 on a complete kart that would be ready to run.  Then add in the trailer.  A set of new tires should run less than $250, shipped to your location.  Another expense can be specialty tools for karting.  Your best bet would be to find a setup from someone who is getting out of the class, or the sport.

But my biggest reservation is the apparent belief that stepping into autocross in a shifter kart might be a good idea.  Although easily the most speed/performance per $invested, a kart is at the same time one of the most difficult to drive and maintain.  Not trying to scare you away, but if your wife is uncomfortable with the idea of autocrossing a small car like the Miata, then she will absolutely freak out in a kart.  If you want to spend a couple of years in a clutch kart like a Rotax, or even a DD2, that might be a way to get in.  But a 6-speed CR125 or IC engine in a kart means doing a lot of things at once, tough for even an experienced autocrosser.

Oh, and make sure that the local club has an acceptable venue that won’t break both the machine and the driver, and that karts are allowed.

 

Edit:

Found this setup, might be something to think about?

http://ekartingnews.com/forums/topic/2008-birel-rx32-w-prd-tag-open-trailer-kart-stand/

[Alan Sheidler]

The lateral G’s seem appropriate, and the braking level does not surprise me either.  But unless there is a 1st gear corner, 2.3 for acceleration seems high to me.  Maybe 2nd gear with a strong motor.  But 3rd gear or higher?

It has been a while since I used a data acquisition setup on a shifter, but I don’t recall getting anywhere near that kind of acceleration after I was already on track.  Standing starts could produce high numbers with sprint gearing, but again, that is for the launch and 1st gear.

The braking and cornering numbers are not affected by speed, but acceleration certainly is.  Aerodynamic drag reduces acceleration as velocity increases, especially on long tracks.  But the big killer at sprint or road racing speeds is the reduction of torque at the rear axle with each change to a higher gear.  As I say, the numbers are fuzzy since it has been over a decade, but in even 5th gear you won’t get 0.5 G, I don’t think.

[Alan Sheidler]

Welcome to the concept of “Parents of Autocrossers”!

First off….  it has been said many times:  If you can get either or both of your children into a kart owned by someone else (share a ride) nearby, that should at least give them a chance to see if they like it.  It is an unfortunate circumstance when youth karts are bought, and not used by the intended driver.

You are correct regarding the classing for your son and daughter.  I have to note that even if they are very close in both size and weight: Using a single kart for both classes is (although possible) extremely difficult.  With the Briggs World Formula engine, the only required change is installation of a throttle slide restrictor for the FJB driver.  Unfortunately, that means a compromise in performance for both competitors, and a hassle for event organizers and other participants, as the two would almost certainly have to run in different heats.

[Alan Sheidler]

Hey Julia,

Not a bad idea to tag the ad here, but you’ll get the biggest audience by posting to the Classifieds section.

Bummer that I never got to run with the Aebersold clan at a major event, but life goes on!

Alan

 

 

[Alan Sheidler]

And yes, you will have to pretty much tear apart the whole engine to swap it out.

[Alan Sheidler]

He’d have to speak for himself regarding the motivation.

But he went for the opportunity to drive a Viper in SSR.  I can’t say I’d turn down something like that either!

[Alan Sheidler]

Very sorry to hear of your injury, Bill.  Sounds painful!

I hope you recover well from it.  As far as driving goes…. the right hand is pretty much for shifting, and just helping the left had do the steering anyway, right?

[Alan Sheidler]

“the first hit is free.”

I think it was Jason Vehige who used to call his kart “The Crack Pipe”

:-)

[Alan Sheidler]

The 4-stroke gearbox 250 has been talked about for many years.

But no one took up the fight to get it approved.  There is at least one company which has a conversion kit to set one up for a kart, likely that would be not too hard to find.  Consult with the current Kart Committee members to see what it would take.  I personally have thought it a good idea for a very long time.

The single drawback always mentioned is the expense of repairs should anything go wrong with the engine.  Top ends of those motors are not easy like the 2-strokes.

[Alan Sheidler]

Daniel is correct.  The limit in CC for a gearbox motor is 125.

If I recall correctly, an allowance is made for a larger single-speed clutch-type.  More than a decade ago I ran a Biland SA250 (4-stroke twin) on a test basis at a Pro Solo.  Way too slow off of the line to be competitive there, perhaps better at a regular autocross?

As far as the overbore goes, for Moto engines at least, it is not possible to do like a car engine, as they have the Nickasil coating in the cylinder.  So, +0.020″ (or 30, 0r 40) is not something which can be done without a subsequent replating.  The answer there is to recoat at the stock bore, if some repair is needed.  Sleeving (typically with iron, possibly an alloy steel) is also prohibited.

There are “Big Bore” kits which increase the CC’s significantly.  Those of course are illegal.

[Alan Sheidler]

Vernon,

Check with Jason Vehige, he runs an electric pump on his autocross kart.

Not sure what his setup is regarding the axle-driven pump.  Anyway, it works well for him.

[Alan Sheidler]

Any information on the engine, to save people from calling about something they would not be interested in?  Also saves seller from unnecessary calls.

[Alan Sheidler]

Greens?

For FJ’s it should be Red label tires, correct?

[Alan Sheidler]

Non-starts can be caused by:

Low compression, or fuel or ignition problems.

We had a non-start issue once which was caused by a failed ground strap.  The wire was coated, so we could not see that it was broken internally.  New ground installed, started instantly.

[Alan Sheidler]

The tube looks to be too high from where it should be in the bowl to me….

Consider that where it extends to is also the top of the fuel level in the bowl.  Too high, and the carb will be in a permanent flood/rich state.

[My PWK is in the workshop, and it is late to get a look at it now.  And I am on a 12 hour shift tomorrow.  Will see if I can get a look and a decent photo for you within a couple of days.]

Edit: I just recalled that I took come pics a while ago for someone else.  No measurements, but see if this helps.  The silver tube upper right corner in the photo is the evac tube.  From my recollection, it extends a little below the bowl seal surface.

PWK

PWK 2. Evacuation tube is near right front corner.

 

[Alan Sheidler]

Blasting leaves a texture, better to use a 200 sandpaper intended for use on metal, and finish with a few passes of 600.  But try to avoid rounding off the edges of the grooves.

The high-temp sealant that seems to work for me is the kind of copper-looking stuff.

[Alan Sheidler]

OK, I edited the list to include Marc and Suzanne, who are running BS/BSL.

And I did not list Russell, who I expect to keep at it until hell freezes over.

Still, we are at barely over 1/3 of last year.  Dismal.

[Alan Sheidler]

First thing to do before installing new o-rings is to use a piece of Scotchbrite pad to take all of the gunk out of the pipe inside, and be certain that the surface is really free from any nicks or deep scratches.  Same for the exhaust manifold, in particular the grooves.  They should be CLEAN.

For years, I only used a bit of clear silicone lubricant that came from NAPA on the o-rings and inside the pipe.  But I have found that they last longer if I use some of the silicone sealant that Sanford refers to.

I’d be curious how well the pipe and manifold fit.  They should be tight and not easy to bring together when the rings are on the manifold.  The one other thing not yet mentioned is the springs used.  If they are not strong enough, too much chafing will result, and premature failure of the o-rings will result.

[Alan Sheidler]

Mathieu,

Look for internet images of the linkage between the brake pedal and the hydraulic master cylinder on karts.  Basically, the standard is a rod with clip-pin joints or clevis types on the ends.  The backup is a cable which would act to provide the linkage if the rod fails.  It is commonly located parallel to the rod, either above or below it, and attached to the pedal and MC lever independently from the rod.

Parts like this:  https://cometkartsales.com/Metric-Brake-Rod-and-Clevis/

[Alan Sheidler]

Have not bought one in many years…

Seems to me that my kids heads were big enough to wear XS size adult helmets, but I am thinking from over a dozen years ago.  I’s ask in a general forum about it, and see what the W2W crowd is doing for the kids.  Not sure that kart racing org’s require Snell.

[Alan Sheidler]

BTW, watch your rear tires carefully.  Neva Hoover and Tim Routh both had tread problems on one tire at the Wilmington Pro.  The tires went back to MG.  Have not heard yet what was discerned.

A while back some of the tires were deflating/debeading during runs, on the inside of the wheel, where beadlocks are rarely used.  MG made good on those.

[Alan Sheidler]

Here is a concept:

The fault is not in the pump system, it is caused by pressure and temperature differences.  As a motor cools, it does develop negative internal pressure, and could therefore pull fuel through the system.

Two of my friends used to run mod shifters at Grattan, but the flooding problems they had to deal with occurred just before races, while they waited in the grid line with full-to-the-top tanks.  Having vents in the tanks did not seem to matter, the motors would flood like you describe.  They had to use shutoffs in the lines as has been suggested.

One of them simply used a pinch clamp on the feed line between the tank and the pump.  Seemed to work.  There were a couple of drivers I saw who would leave the carburetors off of the motor until it was time to fire and warm up prior to the start of a race.  I like the valve idea the best.

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