[Jim Derrig]

Hi Chuck.  I can relate.  One reason I left shifter was my 50+ year old bod was tired of the physical pounding a shifter delivers.

Has TCKC changed its TaG format?  Last time I was there I showed up with a Leopard and had to call myself either a Rotax or a PRD because no other engines were recognized at the club level.   Great track and club, but I thought that was a little strange.

Here’s how I see your choices:

1.  PRD:  Basically, its a Leopard made in the orient.  Good price and good local class, but at a disadvantage if you want to run Gold Cup.  I assume it has the same annoying vibration issue as the Leopard.  I don’t know if it also duplicates the electrical issues I seemed to consistently encounter with the Leopard (ate stators; unnecessarily complex wiring harness)

2.  X-30:  Stronger motor with longer rebuild cycle.  Dicy italian electronics, and only “necessary” if you intend to run SKUSA national races.  Not sure if TCKC is recognizing it this year?  I know Jerry Pitts uses one for Gold Cup but he also has a Rotax and a KT-100.  You will like this motor more than the PRD.  You will pay more for it than for a PRD.

3.  Rotax:  I assume you’ve considered this option and decided against it.

4.  X125t:  Not sure if you considered this one.  Stronger and more reliable than the X-30 and legal for IKF TaG.  No electrical issues that I know of outside of being stuck with the same questionable starter that everyone else uses.  It’s the motor to have, IMHO, unless you’re running Rotax or SKUSA national events.  Cheap if you can find a trade-in, due to Italian Motors’ trade-in program.

 

[Jim Derrig]

It’s possible your the lead wire off the coil is broken or beat up to the point it doesn’t work consistently any more.  Usually its then end with the spark plug boot.  Try twisting off the boot, cutting off an inch of wire or so and twisting the boot back on.

The coils themselves are almost indestructible.

[Jim Derrig]

Well, that helps explain the price.   The downside of getting that “great deal” on the front end is there’s a ton of work on the back end.

You’re about to teach yourself swimming by jumping into the deep end of the pool–a kart fast enough to challenge a pro driver’s skills and an odd-duck motor that nobody else runs and will be able to help you with.  If I were you I’d seriously think of selling the motor on ebay to somebody who wants it for an old Aprilla 125 and converting the kart to a Briggs LO206 or, if that seems to slow, a  KT100 or TaG package (I’m assuming a spec Honda or ICC shifter motor would cost way more than you’d want to spend).

I say this as someone who started in a similar position and almost walked away from karting on more than one occasion simply from being frustrated and overwhelmed.  And I was running a modified Honda that I could get all kinds of track-side help/support for.

I think 90% of the people I see in your/our position quit because they started out with too much kart that required too much work.  50% of them finally got their shifter in running condition, took it to the track once, said “holy shi*t” ’cause the thing was way more scary fast than they had even imagined, and never came back.  I’d see the kart on Craiglist a few months later.  Heck, that’s what happened to the guy I sold my old shifter to.  I’ve seen in on Craigs twice in the past two years.

On the other hand, you could step in and be awesome.  I’ve seen that too.  Have fun.

 

[Jim Derrig]

I’m not a pro engine builder but I’ve rebuilt and successfully raced about 6 Leopards and I don’t think the sort of interference you’re talking about is possible with correct parts and assembly.  I’ve never measured it, but there is ample clearance from the top of the piston to the top of the cylinder, and the concave shape of the head should make contact impossible.  Something is seriously out of spec and I’d be concerned about interference popping up again after the parts heat up and expand, as the available gaskets are not that different in thickness.  You should never have to fashion your own gasket to create clearance on this motor.

I know you want to save $ but seizing the motor at 15,000 rpm will not be the way to do it.  I’m a DIY guy all the way, but as Dirty Hairy said “A man’s got to know his limitations.”  Sometimes you just gotta bite the bullet and pay the man.  Heck, for all you know you’ll get it so the thing will rotate again and you’ll only be back to it not starting.

[Jim Derrig]

Well, this pretty much confirms my guess that something was misassembled the first time.

You’ll have to put the motor in a box and send it to a builder.  I know–$$–but at this point you don’t have much choice.  I’m way over on the left coast, so I can’t recommend anyone over there.  Italian Motors was the IAME importer for decades and knows more about the Leopard than anyone else.

http://www.italianmotorsusa.com/pages/im-engine-building-department

Or you could just trade it in for an X125t–be the first on your block to own one :)  Might be cheaper in the long run.

X125T Engine Package <p style="color:red">*TRADE IN PROGRAM*</p>

[Jim Derrig]

A can of Flat Fix.  Probably don’t need much in each tire.

[Jim Derrig]

If fuel is going through the carb into the plenum, then there has to be some compression pumping the fuel.  The only way I can imagine that NO fuel would  go from the plenum into the crankcase is if the reeds were completely shut somehow.  As I said earlier, the volume of fuel going through the carb is so great at low rpm that you’ll get quit a bit of it dripping out the front of the carb.  Seriously, on my X125t I get fuel dripping out the front even at 4000 rpm.

If you use starter fluid it should fire without choking.

I’m pretty much at a loss and suspect there is something misassembled on the motor, or your ignition system is for an X30 and the timing is so far off the motor won’t start.  You might have to bite the bullet and take it to a kart shop where somebody can give it a hands-on look, as remote internet diagnosis isn’t working.

 

[Jim Derrig]

The trigger/magnet fits over the crank, on the  side of the motor nearest the seat, and sits inside the “donut” of the stator. The magnet position is fixed by a key in the keyway on the crank output shaft.

If the “original magnet” you speak of was off a push-button start ignition system, it won’t work correctly with the key start system and this explains your weak spark.  Though, to be honest the motor will run with the wrong magnet (I’ve done it–blush) so this does not totally explain the non-start.  My guess is the the weak spark combined with no choke may be the reason.

Seriously, get some starter fluid for the first start.  Not ideal, but at least it’ll catch, you’ll get the break in started, and the next start should be easier.

I have no explanation for why the new magnet would be “bored way too big,” as the magnet bores are identical for both (the crankshaft diameter for all Leopards is the same).  Wait, maybe it’s the trigger for the X-30 engine and they sent (or you unknowingly ordered) the wrong ignition kit?

 

[Jim Derrig]

Your compression should easily exceed 200 psi.  The bore cannot possibly be 53.47, as the bore new is 54.00, so your tools or technique are off.

This is real basic, but are you choking the motor for a cold start?  First start can be a bitch for a rebuilt Leopard.  To choke it, put the air box on and place your hand over the inlet tubes.  You might have to slightly wedge open the throttle with a piece of thin (3mm) plastic or get somebody to manipulate the throttle.  You actually can leave the key in cranking position and have one hand doing the choking and the other working the throttle.  I’ve also resorted to spraying starting fluid in the inlet.

You haven’t clarified whether you were using the key start ignition before the rebuild, or if that also is new.  The crank trigger magnet for a push-button Leopard is different than for a key start, so if you mixed them up you can get a very weak spark but no start.

At low speed cranking (like with a starter) the carb can dump too much gas into the air intake plenum, so you’ll get leakage of the excess gas out of the plenum,  that you might interpret as gas not getting into the motor.

[Jim Derrig]

Regarding the toe, you haven’t said whether you are road racing or doing sprint.  The 4mm would be a typical sprint set up as the numerous tight turns  call for enhancing the ackerman affect.

Keep in mind that all of your fine tuning should be done with the tires you will be racing on.  Nice that you got some obscure dunlops for cheap, but they may or may not be close to what you eventually use.

[Jim Derrig]

Andres, I had a 1997 Top Kart at one point, though it was a “Top 125” shifter.  It was nigh indestructable, but very stiff, which might not be the best for your relatively low-power engine.  The good news is that the parts can still be got, as most of them are generic rather than unique to TopKart.

Regardless, your alignment specs are going to depend as much on the track you race as on the brand of chassis.  I’d go to the track with a neutral front pills, 4mm of toe out, a medium axle and hubs, front and back track at maximum, center ride height (i.e., very standard starting point) and take it from there.

[Jim Derrig]

Matt, rotax doesn’t make a 6-speed kart motor.  All rotax’s are single speed with the exception of the DD2, which is quite rare and has 2 speeds.

My Skip Barber instructor said that the next step up from a shifter kart is an indy car, so you’re probably not going to want to start with a shifter.  Tell us what your budget is for a motor and we’ll try to point you in the right direction.  You have a lot of options and you’ve got a good chassis to start with.  Where do you plan to race it?

[Jim Derrig]

Like I said earlier, age limits are a statistical generalization based on the most common situation.  There always will be exceptional people that don’t fall within the normal population.  Luke is addressing the situation faced by young drivers who are exceptional at a national or even international level.  The rules need to have a clause allowing for such exceptions.

On the other hand, once the clause exists, it will only be a matter of time before some overly-ambitous parent yells, cajoles and lobbies enough that his future Lewis Hamilton (not) is allowed to race and trouble ensues.  Nothing’s perfect.

[Jim Derrig]

If it’s a 6 speed then it ain’t a Rotax.  I’m thinking you need to post a pic or two ’cause something ain’t adding up.

The double-calipers-on-one-disc was used for a bit, though I think it was gone by 2010.  Might be a retrofit but the chassis might not be a 2010.

Matt, as far a parts go you’re best bet may be to deal with Italian Motors as they are Italkart.  They have an online store and free shipping. http://www.italianmotorsusa.com If you can’t find it there, give them a call.

Fastect near Monterey also has a lot of Italkart stuff and Jon is super helpful

http://www.fastech-racing.com

[Jim Derrig]

“The big issues we’ve had over the past couple years in the TaG class stems mostly from young kids moving up and having the speed to run up front, but none of the common sense or racecraft. Which results in them running everyone over.”

I agree with this, but suggest that the age factor is a red herring, as a 40-year-old with speed but no common sense or race craft is just as much an accident waiting to happen as a 14-year-old with the same issues.  I’ve raced with 15-year-olds whom I learned to trust implicitly to make the right decisions (and always do so), and 40-year-olds who frankly shouldn’t have been allowed on the track.

The 16-year-old limit is a time honored cutoff and should not be lowered.  However, it should not be an absolute bar to younger drivers with clearly-demonstrated skills.  Likewise, I tend to agree with TJ that regardless of age, a driver should have to spend at least one year in a lower class (or have some other sort of proven racing background, such as MX, SCCA, Skip Barber school, etc.) before being allowed to race TaG.  Most of the craziness I’ve seen has involved newbies jumping into TaG’s or (worse) shifters without any real idea of how to drive (“it’s just a go kart, how hard can this be?”).

 

[Jim Derrig]

Nothing magic happens at age 16.  The age limit is more a statistical rule-of-thumb in that by that time the person is more likely to have a certain degree of discretion, strength, etc. required to race.  The margin of error is wide as the proverbial barn door:  We’ve all raced against “adults” who behave like children and we’ve all seen 14-year-olds who are better in every way than most of the adults on the track.

If a younger person is exceptional and the race director is satisfied, I have no objections, but it should be on a person-by-person basis.

[Jim Derrig]

Matt,

I have a 2015 Rapido and race at Italkart’s home track, so I’m familiar with that kart brand, but we need some details as stated above.  Specifically, does it have front brakes and what engine does it have?  I’m assuming when you said “dual caliper” you meant dual pistons on both sides of the caliper on a single rear axle brake?

[Jim Derrig]

1.  Agree with Freddy, you need a gravity or pressure feeder.  Also, are the hoses routed so any part loops above the level of the bleed screws on the caliper?  If so, you might have an air pocket there.

2.  Although the brakes should be self-adjusting, you might need to shim the pads  on one side to equalize the gap.

3.  Finally, if the spindles are slightly bent/tweeked from contact or temporarily operating the karts as a lawn mower :) this can result in the caliper  being misaligned with the rotor.  Generally you can shim around that.

 

[Jim Derrig]

My personal favorite is when the recovery trailer (for rescuing the broken kart) is parked in the infield somewhere, apparently for the convenience of the track staff.  Really nasty thing to hit, full of sharp angles, etc.

It’s all about awareness folks.  The good news is that every time I’ve seen something like this and pointed it out, something has been done, as usually the situation was created by someone who wasn’t thinking and once the error is pointed out  to the staff–who are busy handling 1000 things–they go “crapp you’re right, thanks for noticing” and move the obstruction.

Or, you can keep your mouth shut and hope you aren’t the unlucky soul who hits it.

[Jim Derrig]

Put a rebuild kit in it, as it’s probably past due anyway.  You’ll need to order the mixture screw o-rings separately.

Tillotson Carburetor Rebuild Kit- Major & Minor

[Jim Derrig]

Sure sounds like an air leak, especially with the dieseling. It continued to run because that’s how long it took to empty the gas from the carb.  Guessing one of the carb gaskets, or the o-rings on the mixture screws might be bad.  Also, is the butterfly valve stuck open?  Try swapping out the carb and see if the problem continues.

[Jim Derrig]

Since Russell sent back one box “external start only,” that means the coil can be energized even if the starter relay is fried (if that is the only thing fried).  Since the box has no other “on” switch other than to engage the starter, the coil likely is energized all of the time (heck, why not?).  This might be a reason why Leopards will drain a battery even when supposedly “off.”

[Jim Derrig]

I’m assuming the starter is grounded through the chassis, but you could run a wire direct from the bat – terminal to a starter mounting bolt just to be sure.  My main concern (never actually owned a push-button ignition version) is whether the primary wire to the coil still is energized now that part of your box is dead.  The “external starter only” box might be the ticket.

I’m really loving my X125t and you could trade in with one 2008 and then sell your other 2008 to offset part of the cost, but the X125t might not be eligible where you are racing.

[Jim Derrig]

Sometimes I think IAME hired a British electrical engineer whose prior experience was with Lucas (“the prince of darkness”)

External starter is your best option.  Option 2 is bypass the box by running a + line direct from the battery to the starter, i.e., a jumper cable.  If that works, splice a high-current switch into the line and mount it permanently.

Option 3 is trade your leopard in for a new motor (welcome to karting, where even cheap racing isn’t as cheap as you’d like).

X125T Engine Package <p style="color:red">*TRADE IN PROGRAM*</p>

http://www.italianmotorsusa.com/collections/used-items

[Jim Derrig]

No.  Are your truly “backfiring” or is the engine missing?  What ignition system are you running (push button box or key start?).  What are the settings (number of turns) on your carb?

Incidentally, splatter and leakage and general “spluge” from a 2-stroke exhaust is pretty much a fact of life. Had it in my Honda shifter; had it in my Leopard.  The only question is where will it come out?  On my Honda the weak point was at the exhaust port.  On the Leopard it was the flex.  My X125T is very well sealed, so it comes out at the end of the muffler and I wipe down the end of my bumper a lot.

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