[Mark Traylor]

Chris,

Just the opposite.   I have a ton of respect for the S4 and the new super masters guys.   I learned about karting form Terry Ives, God Father of the 250 superkart that was a dominant driver as long as he wanted to be.  He stopped driving 250’s (mostly) after a terrible crash at Thunderhill.   What I said I have heard is what I have heard form some guys, I have not taken a survey.  It isn’t to knock anyone at all.  Just more about that I think transition from junior to senior too young.   That perhaps instead of weights being adjusted maybe ages need the adjustment.   There are plenty of 115 pound 16 year olds but not so many 115 pound 25 year olds.

[Mark Traylor]

the weight moving to age is an interesting turn of the topic.   At the end of next year my son will need to move from Cadet to Junior.  If we go from LO206 cadet to World Formula junior or to tag junior / rotax junior I will need to add a good 70+ pounds of lead to his kart depending on chassis that could go up to 90 pounds.   It would be better to keep him in a cadet longer but he will age out.   I know a lot of S4 guys were not happy about S2 drivers that were much younger bolting on a lot of lead and running against older competition in a class that is a little less competitive.  When you compare junior to senior laptimes they are pretty close and could be closer.  Seems like keeping kids in junior longer even if they were lighter so they were as quick as senior would not be a bad thing.   just as the 48 year old S4 driver may not want to run against the 30 year old S2 driver (weight aside) there are probably plenty of 27 year old senior drivers that may not want to race the 15-16 year old.   Perspectives and priorities change as we get older.

[Mark Traylor]

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[Mark Traylor]

Eric,

I agree with your assessment.   everything seems cheap and poorly designed/manufactured.   We were running micro and I will say for that engine it tunes much better.  It behaves logically where as the old micro was just the opposite.   The harness is complete crap.

[Mark Traylor]

dirt is the biggest enemy of bearings.   seals are worth it.  From an engineering perspective the concentra design is great.  I cant say it is worth the expense but i love the collet design.

[Mark Traylor]

Pat,

I do think from an engineering perspective that your definition of composite is flawed.  The bearings are certainly hybrid but that is not the same as composite, nor is the ceramic silicon nitride a composite.   First a composite material are two different materials that are combined to provide a material property different than the two (or more) materials individually.  Typicaly thought of as fiber and a resin in todays day and age (rags and glue).  It does not need to be this way it can be concrete, a mixtrue of portland cement, gravel and sand, or a natural composite of wood.  the ceramic balls and stell races do not interact this way, they are merely a mechanical system.  The silicon nitride also on its own is not a composite material, it is silicon nitride that is formed into blanks by a sintering process of applying  heat and extreme and pressure as the agent, no matrix or “glue”.  Funny enough I have heard in technical papers carburized steel referred to as a “self assembling nano composite” (bearing steels are carburized).  This is actually a more accurate definition of composite that silicon nitride as you have iron as the matrix material.

All that being said no one is going to be beating you due to ceramic bearings.  Most karts I have encountered have atrociously dirty bearings, keeping your bearings clean will result in longer life and better performance where ceramics have the real improvement is in product life.  I am sure many will argue this and I don’t really care.

[Mark Traylor]

could be worse.   I was with a buddy at Willow springs and saw that it looked like a part flew off the kart in turn 9 with a Rotax 257.   Turns out the piston failed, hit the cylinder head, broke the cylinder in half an flew out of the engine.  The piston was found 200 feet off the track.

[Mark Traylor]

Craig,

my upgraded micro has been hitting 10,800 regularly at our track with a pretty long back straight.   Don’t worry about what the jetting should be.    Follow the signs in the tune.   What you described makes it seem lean.   Read the pipe.   I have found the Evo, while finicky, to be very predictable and it behaves logically the way that you would expect a 2t to tune.   The old carb seemed quite counter intuitive to me relative to past 2t engines I tuned.

[Mark Traylor]

BTW…what is the experience level of your driver?

[Mark Traylor]

go ahead and replace the fuel pump gasket but if it wont  pull out of the corners well you are too lean.   And the carb set up you have said is pretty lean.

[Mark Traylor]

Holeshot Drive systems (AJ Whistler) recommends very highly Alisyn synthetic chain lube.   It is great.  it is a high quality synthetic grease dissovled into an volatile.  So it sprays on and wicks in then the volatile evaporates and leaves the grease in place.   best thing is the exact same lube is also sold at home depot under a product name “Clopay Synthetic Garage Door Chain Lube” for about $6 a can  Also at Lowes as “Genie Synthetic Garage Door Chain Lube” at about the same price.   It really is the same stuff, it is a great product, easily available at a reasonable price.

[Mark Traylor]

Samir,

Yes, the cylinder swap must be done by a service center.   it requires cutting the top end seal.   Do not buy any engine that does not have a lettered cylinder already They will not be legal and you will have to replace it at a potentially very high cost.   A good rotax cylinder can cost well over $1000.  I have seen them sell for $3000 to $5000.  That is for a cylinder only.   I do have a very good engine that I have been on the fence about selling.   If you have not purchased one yet contact Christian Fox.  He and I talk a lot about our engines and tuning so he can vouch for me.

[Mark Traylor]

Mark,

That is an impossible question to answer.   There is too much variability in cylinders and other parts with the rotax.  Mt prevo responded good to the upgrade, others better or worse.   I have seen evo’s that run about the same as mine and other much worse than min side by side.  If you have a good engine with a legal lettered cylinder then I am confident it will still be a good engine.   Copmparing that to a brand new engine is difficult as you will be getting ht eluck of the draw on the cylinder you get with the new engine.   Over the next year everyone that spends a lot of time, money and effort on rotax will begin to identify the good from bad cylinders.  I have not seen a brand new engine that ran on the same track on the same day that was measurably better to my upgraded engine.

[Mark Traylor]

BTW…there have been issues with the PV.  check the bulletins for changes

[Mark Traylor]

188-190?  Is this a DD2?  I used to run a 150 in my old senior.   with Evo people are down around 120 on the main for senior and around a 130 in DD2.   The carburation is very different.

[Mark Traylor]

maybe a little appilcation of dielectric grease on the connector would help?

[Mark Traylor]

Michael,

Which connector?  I have heard of bad harnesses.   cant miss the giant “made in China” tag.

[Mark Traylor]

Micro max is now open on the jetting.  Not restricted to the one kit of jets.

[Mark Traylor]

I have heard from one dealer that I wont name that he has had a bad harness and a couple of the 25 pin connectors tot he ecu go bad.   So I don’ believe they have heard of no issues.  This dealer has been working on getting parts replaced for a while now.

[Mark Traylor]

I emailed mine in a couple days after opening and did get a call this week.  It should be about the same with or without the turdown.  maybe a tiny bit better without it.   They are working on replacing them.  you should call them.

[Mark Traylor]

There have been some micro kits shipped witht he wrong exhaust stinger.  Maxspeed has a list and they are working it but I know at least 2 guys in SC that got the wrong one.  If you got a kit with no turndown on the stinger they sent you the wrong one.   Give them a call so they can get it taken care of.

[Mark Traylor]

It is a difficult issue on both sides.  Were are racing split and the points are being adjusted but that doesnt change the frustration of a 9 year old kid.

There have been some micro kits shipped witht he wrong exhaust stinger.  Maxspeed has a list and they are working it but I know at least 2 guys in SC that got the wrong one.  If you got a kit with no turndown on the stinger they sent you the wrong one.   Give them a call so they can get it taken care of.

In CanAm they had to turn to outlet to point up instead of down because bumpers were being melted by the exhaust.

[Mark Traylor]

Thanks aaron.   Sounds like a brass slide stop will wear out pretty quickily.  the old steel ones would wear out.  Unless the brass is thick enough to reduce the contact stress significantly I would be expecting to check those regularly and swap them out more often.

[Mark Traylor]

I placed my order on day 2 that they order form was available.  The problem is that the whole program was rolled out incomplete and in a very inefficient way.  There is a world wide distribution network for one.  Use it.  the upgrades should not have even been offered until there was a reasonable supply available.  When the order forms were made available there were only 10 upgrade kits available.  Sorry but that is ridiculous.   At least on the micro max side the deal was rolled out prematurely, there was no testing done and now it is being done on the fly.  People are running races and there are some competitors with new engines and those without, maybe not a big deal in senior but in micromax it renders the prevo uncometitive and now there are new throttle stops being passed out the first day of a national racing series.

lessons to be learned:

1)  Get the technical work done in advance so you are not bandaiding along  the way.

2)  Get parts in stock in sufficient quantity before releasing order forms

3)  Use the vast dealer network to your advantage as to avoid overloading a small office staff that is not geared up to handle a direct to end user distribution nightmare.

[Mark Traylor]

We still have not received a micro upgrade.   The people that have upgraded engines here (from parts off of brand new engines) have had no plroblems tuning.   Just the opposite in fact.  My first reaction has been that people are running them far too rich and I think many have been but I now have heard of two people that have run them lean and rich with still having lots of problems.

 

 

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