[Mark Traylor]

I have heard that Maxspeed is expecting a shipment of parts this week to hopefully complete a bunch of kits (hopefully micro kits for me).  That said we had a race this weekend with some interesting results.

We had 4 micromax, three upgraded and 1 prevo.  a couple had the option to run new evo engones but ended up stripping parts off the new evo and upgrading the prevo.  Basically the evo is better tha prevo as everyone would expect but the upraded prevo was better than the new evo.  the engines that were upgraded were good engines to start with.   So basically if you have a good engine you will in all liklihood still have a good engine and better than a new evo out of the box.  I am sure there will still be the hunt for good cylinders that are lettered.  It does not seem that an out of the box engine will run with an upgraded engine that has gone through parts selection and development.

We did not have an upgrade yet so we elected to run in the LO206 Briggs class.

[Mark Traylor]

Eric,

I think you are probably still way too rich.   and going to the cold plug when you are very rich will make it worse.  a hotter plug like an IW24 may have worked better.    There some an interesting turn of events for the micro class at our track.  Ill will post a report on the  upgrade thread I started.

[Mark Traylor]

Ambrose,

the serial number is the dot peened number typically 7 digits long that is at about the 2:00 position when looking at the clutch.

[Mark Traylor]

Eric,

I think you are still just far too rich.  Remember that your engine requires a certain amount of fuel to make a certain amount of horsepower, but a completely different carburetor will deliver fuel differently.  Basically you cant compare a 128 in the old carb to a 128 in the new carb even though they look the same.  the floats are richer, the idle circuit is richer, the needle and the emulsion tube are totally different so you end up with a completely different tune.   We had a senior out on saturday with an upgrade and he was down to a 120 main.  Other micros I have heard about are all under a 110 and I have heard ranges of 90-105 for mains on the micro.  I run a 125 typically on the current engine config.   Also remeber witht he old carb you had the throttle stop in so the needle never opened the emulsion tube and ran completely on the main jet, the new carb doesnt use the trottle stop and runs as the carb is designed to, on the needle for part throttle and on the main at full.

Did you pull the pipe and look at it?  My bet is that it is very black and probably a little wet too.

[Mark Traylor]

Mark Parks,

There has been some testing results that I have read saying that the upgraded engines are comparable to the new.   The testing was not extensive but sounded like they did a good job adding one evo component on at a time and comparing it to their best team equipent.   However they only ran Junior Senior, and DD2.  No mini or micro so as far as those go who knows.

[Mark Traylor]

I read through the March 16 regs.   the supplement for the Micro and Mini refer you to the main regs section 6.8 (should be 6.9) for the XS carb.  there is not specified range of jetting so my assumption is that Micro jetting is totally open.

[Mark Traylor]

This is interesting.   the US does call for lettered cylinders only on EVO engines in micro and mini engines.

“5.5.1. EVO Engines
Evo engines must use a cylinder marked with lettered production code. Letters are different from one production batch to another.”

But you could read this as pure EVO, not upgraded PREVO.  Not sure what the intention is but it was not spelled out.  I could certainly see the desire to stop people from mixing the 2009 “super cylinders” with the new engines.

Also when reading the supplemental regs for Micro and Mini it is clear I was wrong on other details I have stated here.  BAsed on conversations with Josh it sounded like there would be not changes to allowable micro jets witht he Evo engines (Rotax is still shipping with the 115-130 jet kit)  Only regs in the supplementals on the XS carb refers you to section 6.8 in the full regulations (airbox regulations), actually should be 6.9.   6.9 does not specify any jet restrictions so micro should be totally open on jetting.

 

 

[Mark Traylor]

Thanks Bruce,

I have publicly flogged myself for stupidity this morning.   When I looked into smaller jets the dealer I spoke with told me the smaller ones were M5.    I must have gotten the new guy in the shop.   In the past I would call Josh Smith and tell him we need to change the rules on allowable jets for micromax, now I have no clue who to talk to there other than talk to my local dealers and get them to call.   Who knows.  I am sure it will be changed but they are still shipping Micromax engines with the 115-130 jet kit.   Just goes to show that BRP pretty much overlooked micro and mini.

[Mark Traylor]

When I spoke to josh at COA there was no plan to change micro jet range yet.   I’m not sure how someone was running a 90.   I am pretty sure the jets that fit in these emulsion tubes only go down to 112. The 90 to 100 are the jets that cars used in the mini rok engines.   Those jets have a smaller thread.

[Mark Traylor]

No min that i am aware of.  The micro has a minimum of 115 so you could run your junior leaner leaner than a micro!

[Mark Traylor]

Brett,

I thought with EVO you could not make any changes to the carb other than Main, needle position and idle air screw.   I thought inner and outer pilots, floats etc. were all fixed (float height ok within the legal range.   I was told that for micro anyway.   odd deal though is the smallest jet made for the carb ia  a 112 and will probably be too large for micro but thus far the range of legal jet (115-130) for micro are still all that will be legal.  Micros will be crazy rich is my guess.

[Mark Traylor]

Brett,

From what I have heard you are probably still really rich.   Others have been down to a 116 main on junior and that was at sea level.

[Mark Traylor]

Mark Parks,

The Prevo micro carb requirs a stop that is inserted into the carb cap.  The split tube that has the cadmium plating on it.  It restricts the micro to about half throttle.  The  new XS carb on the micro does not use that stop inside the carburetor, you can run full throttle on the new carb.

Mark

[Mark Traylor]

Mark Parks,

I am sure you realize this but don’t forget that the Evo micro does not use throttle stop in the new carburetor.

[Mark Traylor]

Yes Mark, the header is smaller and the muffler tube and outlet are larger.   To address the complexity comment I made above you can run all Prevo or all Evo (upgrade) but no mixing of the two.   You can not run the old header and new carb, or old ignition with new carb, or new ignition and old carb etc.   that sort of mix and match would create a nightmare matrix of complexity that would further the gap between the haves and have nots to the extreme.

There are unconfirmed rumors regarding the future of certain cylinders but it is all rumor and guessing that I do not care to broadcast publicly.

[Mark Traylor]

yeah.  Question remains is can you take 200 cylinders, ignitions, carbs etc. and now make a 9hp micro.   we wont know for a while.  Maybe we get one year of better parody?  If there is money to spend someone will spend it.  You can not control spending, only complexity.

Once upgraded will that near 8hp micro now make 9 with no changes or will it still be about 8?  the impressive thing about the Evo micro curve is not the peak hp.  Peak hp can be really deceiving particularly in a single speed vehicle.  The width of the curve and area under it is what is impressive.

[Mark Traylor]

Mark,

The micro is the one engine with very different performance numbers based on the published power curves.  For instance the Prevo peaked at 6.8hp at 6500 RPM and then continously falls off to 3.2hp at 10,500 RPM.  the Evo curve says it peaks at 8.1 hp at 7000 rpm and holds the 8hp 8200rpm then drops to 7hp and holds at 6.5 to 7 hp up to 11,000 rpm.   Then it drops quickly to 2.6hp at 12,000 rpm.   so the hp at 10,500 is double the Prevo.  There is about 30% more area under the Evo power curve compared to the Prevo.  The Evo will be quite a lot quicker than the Prevo (not upgraded).  Hoopefully the upgraded prevo will be on par with the full Evo.  The current murmurs seem to be positive in that respect but we will soon find out.

 

This is all from PUBLISHED curves.   Not real dyno data I have access to.  SO it all depends on how much the BRP marketing department pencil whipped the curves.

[Mark Traylor]

Mine has been in 2.5 weeks.  No call back.   I did get emails back following emails to them.   They won’t contact you until they have a kit available for you.

[Mark Traylor]

you can race with or without the upgrade in any series.  The Micro class sees the largest difference in performance.

[Mark Traylor]

That is odd Christian.  I asked a couple dealer friends about it and they had no parts but they have gotten complete engines.  They thought that the online guys selling parts are buying engines and offering the parts for sale.  I guess if someone is in a giant hurry to get the parts and start testing they may pay the retail prices for them.  I know I can’t do that but some people can.

[Mark Traylor]

I have heard Junior running a 116 and senior on a 118.  That comes from a south african article that has had the evo engines for a little while.

[Mark Traylor]

As far as missing race dates due to no upgrade kit I think most series are delaying implementation until parts are readily available.   That is a decision that is left up to the individual series.

That said I agree that the kits need to be offered once there is an ability to fullfill the demand.

[Mark Traylor]

I did hear back from Maxspeed.  They sold kits out nearly immediately as they had an excruciatingly small quantity of kits.  They apparently do  have DD2 kits but that is all and just a few.   They wont have for for about 4 weeks.  I would think that there will be a ton sold, even to people well out of racing just so that the engines could be sold just as it was with HPV/KPV.  With the installed base of Rotax I would guess they will be selling near 2000 of these kits.  It seems like a nightmare for just a few people to wade through all the serial numbers and make calls back.  Maybe I am way off and only active racers will be buying any of the kits but if I had an engine just sitting around I think I would buy the kit so it can be sold.  after the kit goes to retail price an non upgraded engine wont be worth anything.

[Mark Traylor]

Can call or text to 480-888-5672

Mark

 

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