[Brett Clatt]

Need two rear bearing cassettes, brake lines and factory exhaust supports. If you have these please email me the prices.

Thanks,

Brett

b.clatt5280tgi@yahoo.com

[Brett Clatt]

Now its at $2100. :)

[Brett Clatt]

$2250 + shipping

Unser Racing has done all the work to it.

[Brett Clatt]

$2300 + shipping ;)

[Brett Clatt]

$2400+shipping

[Brett Clatt]

Any new news yet? I haven’t seen anything yet. I’m getting anxious since our season starts in two and a half months. I don’t feel like dumping cash to have spare old style harnesses, but I also don’t feel like waiting to the last minute for Rotax to make a decision.

[Brett Clatt]

Sorry about that, been extremely busy. I’ll call you tonight.

Thank you,

Brett

[Brett Clatt]

What kind of temp are you all running your EVO’s at? Ours seems to really like 165degrees.

[Brett Clatt]

I have 110-130 jets for the new EVO Junior motor. Here at altitude we were able to get over 13,300+rpm using the 120 jet. Using the 130 it came with we only topped out at 11,800rpm.

Also, when we tested smaller jets we never came across the “popping” that signifies too lean like we did with the old style motors.

[Brett Clatt]

Michael,
What kind of RPM’s were you trying to get out of the Junior motor?
You’ll definately want to stress relief the connectors. I’ve heard a complaint about the electric power valve on the EVO senior/DD2 motor, but nothing negitive about the junior upgrade.

[Brett Clatt]

Not included with the upgrade kit.
You get the ignition, wireharness, power valve, carb and battery box.

[Brett Clatt]

Do the holes still have to be opened up to 22mm on newer karts to install these?

[Brett Clatt]

Here’s some runs with the new EVO Junior motor on Monday at IMI here in Colorado.

Elevation: 5,400′, Temps: 56-70 degrees, Humidity: 17%, Fuel/Oil: 91oct 44:1 mix, Needle Position: 1, Motor temp: 155-163

128 main jet 13,148 rpm

125 main jet 13,191 rpm

122 main jet 13,210 rpm

120 main jet 13,315 rpm

119 main jet 13,024 rpm

118 main jet 12,988 rpm

117 main jet 12,721 rpm

116 main jet 12,973 rpm

We would do two hard pulls on the long back stretch to see what our RPM would climb to. Didn’t have any “popping” even with the 116 jet. Ran 79/12 gearing to make sure we got the RPM’s up. And had a new IW27 plug in. We’ll be going out again next weekend.

 

 

 

 

 

 

 

 

 

 

 

 

 

[Brett Clatt]

Thanks guys for the feedback.

[Brett Clatt]

Bruce,

Totally understand the % reduction when you get that low. At 120 we absolutely can’t get above 12,200rpm with a 79 gear and a total weight of 325lbs. Racing in the mile high city adds another dynamic to jetting a 2cycle. Ordered jets from 112 to 118. Going to just try stepping down until we get higher RPM’s. Switched the idle jets back to 60/45. Thanks for info. I’ll post sunday night after we run to see if we can gain some RPM’s and low end.

[Brett Clatt]

Bruce,

Thank you. That will save me some time and money. Going to try a 112 and 116 main this coming weekend. Got the needle position at 1. It may be a struggle to get the EVO motors lean enough here at altitude…..

Did Rotax specify a minimum jet size for the EVO Junior?

[Brett Clatt]

Mark,

This is what I found for the 2015 regulations for the “Junior EVO” carb…. Please correct me if I’m reading this wrong. It looks as though that I can change the “Idle Jet” and “Inner Jet”. I think. LOL
Idle jets stamped 30, 35, 40, 45, 50, 55 and 60 only are legal to be used. It is not mandatory that idle jet and idle emulsion tube show the same size.

Plug gauge 0,65 mm may not enter the bore of the idle jet 60 (use jet gauge set Rotax part no. 281 920).

Idle emulsion tube:
Idle emulsion tube stamped 30, 35, 40, 45, 50, 55 and 60 are legal to

be used.

It is not mandatory that idle emulsion tube and idle jet show the same

size.

Plug gauge 0,65 mm may not enter the bore (use jet gauge set Rotax

part no. 281 920).”

 

[Brett Clatt]

Good to know. Thank you for that info. One guy at the track yesterday has a Senior EVO and he was running a 118 and said it still felt rich. Going to try a lot more combinations next weekend until we get it figured out. Kind of a new learning curve from what we were used to here at altitude with the pre-EVO motors.

[Brett Clatt]

Had the 2015 Junior EVO out at the track all weekend. Did the break in Saturday and ran it all day today. Here in Denver the altitude plays a big roll in jetting. We’ve been having one hell of a time getting the rpm over 12,200rpm. We’re down to a 120 main jet and 45/45 idle jets. It does produce awesome power from 8-11,000 rpm, but the sub 8,000rpm bog is devastating right now.

We broke it in at a one mile track that is fast. The Junior EVO performed great there, ran the same times as the Senior motor. On the tighter shorter course today we were struggling.

More testing next weekend.

[Brett Clatt]

Going to take the new EVO Junior out Saturday morning for a couple of break in runs. I’ll post a video and opinion when we’re done.

https://www.facebook.com/pages/WMMC-Racing/480525108755364

 

[Brett Clatt]

I submitted my info for the Senior kit on February 17th and they sent my package on March 10th.

[Brett Clatt]

I used M8x80mm flat heads with the counter sunk fender washer. Just use a grinder to put a flat spot in the end and then you can drill a hole for safety wire and double nut it.

[Brett Clatt]

Good to know. I sent my info to them for a senior motor I have on the 19th of February and hadn’t heard anything, at least I’m not the only one.

[Brett Clatt]

M Crotty

We have the 2015 Junior and ran the jet down to a 115 and the motor temp at 164 degrees and we had no pop to indicate that the motor was too lean. We tested from 130 down to 115 and noticed a definite wave pattern in the RPM’s with a 120 jet giving us the best performance.

Maybe the “pop” indicator is no longer valid…..?

[Brett Clatt]

andy-graham

We haven’t got the Junior running 100% yet, but my son did say that the motor felt very strong compared to his Senior motor in the 8-11,000rpm range. Haven’t tracked lap times since we are still fine tuning. I’ll post with comparative times when we get to that point.

[Author]

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