EVO Symptoms/Failures/Remedies

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Bainesy36
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EVO Symptoms/Failures/Remedies

Post by Bainesy36 » Sat Aug 15, 2015 2:23 pm

Hey all,

I know that a number of us here at the club have suffered, or are suffering from issues with the new EVO Upgrades. I thought I'd post my problem here and I hope others will follow suit to enable any future issues to be diagnosed quicker based on other people's findings so far.

SYMPTOM
After installing my EVO upgrades, the kart ran great with no issues. In the last 2 weeks or so, I've been experiencing a loss of low RPM power exiting the two slow hairpins of turns 11 and 13 (running Clockwise now).

FAILURE
After trying a number of things to improve the situation, I eventually found that my issue was caused by the Power Valve (PV) staying open below 7600rpm. The reason this was happening was due to a broken wire at the connector for the PV Solenoid for me (see pictures). We have also seen the wire from the Ignition Connector to the PV Solenoid be damaged at the Ignition Connector too.

Image
Image

REMEDY
As the problem is part of the new wiring harness, I had to replace the complete harness to fix the problem.

Whilst trying to fix the low RPM power issue, I went through a number of things before finding the problem. When I first noticed the issue I observed the PV on the stand and I could see it opening and closing but couldn't say for sure it was 0% - 100%, so thought maybe it was never closing fully. Carb adjustments made no real difference, changing the exhaust packing, air filter, spark plug, re-building the fuel pump etc etc obviously had no impact either. I was always concerned that it was PV related and my gut feeling was that it wasn't closing fully below 7600rpm and Joey from Overdrive Motorsports mentioned that maybe the slide was sticking in the cylinder. After speaking with Joey, it appears that the earlier cylinders (mine is an '06) have a slightly different casting to the later ones ('09 onwards?? can someone confirm this year?). This means that with the new PV assembly, the body of the PV fouls on the cylinder and 'could' cause the alignment to be out on the slide valve and possibly cause some binding in the cylinder. The bottom of my slide already shows signs of wear on both sides of the underneath, suggesting this may have been happening with mine. I have filed the body of the PV since and also some of the cylinder casting to ensure there is daylight between the two. I believe this was found on a DD2 first of all.

Anyway, whilst I was running my kart on the stand 2 days ago, I observed the PV and noticed that it opened at 7600rpm ok, but was closing way below that at around 5000rpm, before eventually staying open all the time. I suspected the PV Solenoid had failed, so tried a known good one, which seemed to work initially, before doing the same thing. I then tried another Ignition module suspecting it may not be sending the signal to the PV Solenoid, but the same thing happened as with the solenoid. I am running on the 'Pressure' set-up for the PV and the way the solenoid works is as follows:

* At start-up, the PV Solenoid has 0V to it and it is open between the bottom, silver port to the side port which allows the pressure into the PV, thus opening it up slightly
* At 3000rpm after initial start-up, 12V is applied to the PV Solenoid from the Ignition module which switches the Solenoid to allow the pressure built up in the PV to be vented back through the side port from the PV to the open vent port on the top of the Solenoid, thus closing the PV
* During normal operation, the PV is closed below 7600rpm (or 7900rpm if you have both ground wires connected) and the PV Solenoid has 12V 'applied' to it from the ignition module with the Solenoid in the venting position
* When the RPM increases to 7600/7900rpm, 12V is 'removed' from the PV Solenoid and switches to the pressure position allowing the pressure from the Crank to be applied to the PV Bellows, opening the PV up
* As the RPM decreases below 7600/7900rpm, the procedure is reversed and the Ignition module 'applies' 12V to the PV Solenoid again, switching it back to the venting position which removes pressure from the PV Bellows, allowing it to close

Due to the ignition module and solenoid not fixing my problem, the only common part was the harness. When I ran my Kart on the stand again yesterday before changing the harness, I tried manipulating the harness around the plug connector to the PV Solenoid and I could get the PV to work from time to time. After the umpteenth removal of the connector, the wire above broke off, revealing the cause of all my problems. The copper wire inside had obviously broken some time ago, but the outer red insulation was still intact causing me to have intermittent issues as the wire would touch back together sometimes, allowing the PV to work on occasions. So, even though the harness appears to have fixed my low RPM power (track test not done at time of writing), it's nice to know 'exactly' what was causing it within the harness. Obviously, another connector with 2 flying leads would be all that was needed to fix this, but it should be a warranty issue for the harness anyway.

Sorry for the long post, but hopefully we can build up the info' regarding EVO issues here to help everyone in the future until Rotax fixes their mess (fingers crossed), otherwise we just replace poor parts with more poor parts. I will also attach the link to the updated wiring harness installation from Rotax here too:

https://gorotax.com/information-bulleti ... -function/
Last edited by Bainesy36 on Wed Aug 19, 2015 8:05 am, edited 4 times in total.

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Bainesy36
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Re: EVO Symptoms/Failures/Remedies

Post by Bainesy36 » Sat Aug 15, 2015 2:28 pm

SYMPTOM
Kart would not rev past 12500rpm

FAILURE
Power Valve Solenoid was stuck in one position and wouldn't switch when the Ignition Module sent the signal to it, leaving the PV itself fully closed all the time

REMEDY
Replaced PV Solenoid

This happened to Brian Taylor earlier in the season. He was still running on the Vac set-up at the time and it caused his PV to be closed permanently. Replacing the faulty Solenoid fixed this for him.

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John Kwong
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Re: EVO Symptoms/Failures/Remedies

Post by John Kwong » Sun Aug 16, 2015 10:22 pm

Wow! Thanks for the detailed description of this problem. I have been lucky so far but at least I will know where to look if this starts to happen on my kart. Electrical gremlins can be tricky to get rid of. I posted this on the ekartingnews Rotax forum so that others can take this in.

John K
John Kwong___CIR Realty___403-294-1500
www.johnkwong.ca
http://kartopractor.weebly.com/

Rob Kozakowski
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Re: EVO Symptoms/Failures/Remedies

Post by Rob Kozakowski » Mon Aug 17, 2015 8:53 am

Issue 1: Engine (Sr Max) would rev to about 12000 rpm, then it seemed power would cut out, making a horrible "fluttering" sound.

The fix was simple - I installed the gasket behind the crank sensor and no more trouble.

Issue 2: Engine (DD2 - newer style with lettered cylinder) had no top end power.

It turns out the power valve would get stuck in the closed position. This issue was mentioned already. We had the PV off, and it would slide up and down into the cylinder with ease, so it seemed the valve itself was ok. We thought the stud that screws into the valve might be bent, causing things to bind - someone else had that problem), but there was nothing that appeared horribly wrong. We tried filing a couple things, and when loosely assembled, the PV would move, but once it was tightened into place, it would close, then get stuck there.

Finally, Joey took a look at it and noticed the power valve housing was rubbing against the cylinder, causing a slight misalignment. A tiny bit of filing of the outside of the PV housing, and the problem was solved.

Bottom line, you want to see some daylight between the cylinder and PV housing, or your PV might not operate properly.

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Re: EVO Symptoms/Failures/Remedies

Post by newson48 » Wed Aug 19, 2015 12:57 pm

One more symptom / fix.
Engine does not rev all the way to top-end. Sounds like a fluttering sound coming from exhaust, typically at high RPM on straightaways. Sometimes poor performance in other places on track as well.
If your solenoid is hard mounted to the bracket, then shock and vibration are overcoming the spring in the solenoid and it is bleeding air off your power-valve. In other words, your power-valve is closing at high RPM's. This is what makes the fluttering sound and prevents the revs from going higher.
Solution. Use the rubber vibration isolator(s) to mount your solenoid to the bracket.

Blake
2Fast4U

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Bainesy36
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Re: EVO Symptoms/Failures/Remedies

Post by Bainesy36 » Wed Aug 19, 2015 11:27 pm

Thanks for the input guys!

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Re: EVO Symptoms/Failures/Remedies

Post by newson48 » Thu Aug 20, 2015 12:32 pm

Here is my video of the Power Valve operation with the solenoid hard mounted to the bracket.

https://www.youtube.com/watch?v=rcTQYOnH49g

Blake
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Re: EVO Symptoms/Failures/Remedies

Post by John Kwong » Wed Oct 28, 2015 8:05 am

Rotax just released the following bulletin:

Click link to see the graphics on the pdf.

http://kartlink.com/wp-content/uploads/2015/10/2854.pdf

CUSTOMER INFORMATION
COMPLAINTS ON EVO ENGINE SERIES Dear customer,
By end of 2014, after completing the development and testing program, BRP-Rotax has launched the new Rotax evo engine series to the market.
Beside a principal positive feedback of the market we have received various complaints on component failures and instable function of the engine.
The main complaints have been related to
1) electronic timed exhaust valve not working properly
2) failures of the new evo con rod
3) failures of the cable harness resulting in an instable function of the engine.
We would like to provide you following comments regarding these matters.
1) ELECTRONIC TIMED EXHAUST VALVE
At the start of serial production we have supplied engines to the market where the crank case pressure has been used to close the exhaust valve (spring below the exhaust valve piston).
The ambient pressure at different altitudes caused a temporary unstable function of the exhaust valve.
To assure a stable function and accurate timing of the exhaust valve, Rotax has taken the decision to change the system and using the crankcase pressure to open the exhaust valve (spring on top of the exhaust valve piston).
As of following engine serial numbers the updated system is supplied as original equipment.
8398316 (125 MAX evo)
8382456 (125 MAX DD2 evo)
For all 125 MAX evo, 125 MAX DD2 evo and evo upgrade kit “e-exhaust valve” which have been supplied before, we offer since May 2015 an update kit (Rotax 481 265) free of charge via our service network.
If you have any doubt on the proper function of the e-exhaust valve, please contact your Rotax service center/dealer regarding support.
INFO 2015 10 23 Page 1/3 Without commitment to advise modifications

2) EVO CON ROD
With the evo engine series Rotax has introduced a new con rod which has been designed with a clear focus to improve the durability of the big end bearing. All tests for the start of the serial production have been positive confirmed that we have reached our development goal.
With the beginning of the racing season we have received complaints of failed evo 1 con rods.
These con rod failures have been analyzed and out of this the design of the evo 1 con rod has been slightly modified (= evo 2 con rod). This modification has significantly improved the durability of the con rod regarding the failures occurred on the market with evo 1 con rods.
As of following engine serial numbers the new evo 2 con rod is fitted as original equipment.
8398340 (125 Micro MAX evo, 125 Junior MAX evo, 125 MAX evo) 8382455 (125 MAX DD2 evo)
In the specific case of an evo 1 con rod failure, Rotax will accept warranty claims up to 12 months from date of purchase of the product (as an extension to the regular Rotax manufacturer’s warranty of 6 months).
Special offer
Customers owning a Rotax engine with an evo 1 con rod fitted will be offered, an evo 2 con rod kit free of charge if they would like to renew the con rod kit at the annual engine overhaul.
This offer will be valid until end of February 2016.
If you have any concern regarding the con rod fitted to your Rotax engine we ask you to contact your Rotax service center/dealer to verify your specific situation.
3) EVO CABLE HARNESS AND ELECTRICAL COMPONENTS
We have carefully analyzed reported failures of OFF/ON/START switches and cable harnesses in the field.
The claimed OFF/ON/START switches have failed due to an internal contact failure.
The technical design of the internal contact has been modified to ensure a faultless function.
A failure of the OFF/ON/START switch is covered under the regular Rotax manufacturer’s warranty. A failed switch will be replaced by a switch with improved design.
The claimed cable harnesses showed either broken connectors (ground wire, starter relay) or internal contact failures in connectors.
The vibration of the electrical components (ECU, ignition coil, magnet valve), caused by engine and vehicle vibrations, can have a negative impact on the durability of the cable harness (depending on the installation of the cable harness in the kart).
The cable harness has been modified in the critical areas to ensure durability and faultless function.
A failure of the cable harness is covered under the regular Rotax manufacturer’s warranty.
A failed cable harness will be replaced by a cable harness with improved design (as of January 2015).
A lower vibration level of the electrical components (ECU, ignition coil, magnet valve) has a significant impact on the durability of the cable harness.

125 MAX evo
To minimize the vibration level of the electrical components BRP-Rotax will initiate an exchange campaign for the support plate which carries the ECU, ignition coil and magnet valve in combination with the improved cable harness.
The support plate supplied with the evo engines or the evo upgrade kits will be replaced by a redesigned support plate system (see illustrations).
This exchange campaign will start in January 2016.

125 MAX DD2 evo
We ask you to contact your Rotax service center/dealer to arrange the exchange campaign for the support plate and cable harness.
BRP-Rotax is confident that the combination of improved cable harness and redesigned support plate system will provide a durable solution resulting in a stable function of the evo engines.
Finally we would like to point out that we are very sorry for any inconvenience caused by the technical problems during the introduction of our new evo engine series.
Taking our responsibility serious we are offering the above mentioned support programs and are hoping for your continued loyalty as a ROTAX customer.

Best regards,
BRP-POWERTRAIN GMBH & CO KG
INFO 2015 10 23 Page 3/3 Without commitment to advise modifications

John K
John Kwong___CIR Realty___403-294-1500
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Joey Guyon
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Re: EVO Symptoms/Failures/Remedies

Post by Joey Guyon » Fri Oct 30, 2015 12:35 pm

Hi All,

In response to the bulletin that John pasted above, I spoke with Rotax and their response was favourable to replace connecting rods to clients who:
Bought a complete Evo engine in 2015
Serviced/rebuilt their Rotax engine with a Evo conrod in 2015

They will provide the conrod at no cost if I complete the install, though there will be labour charges. Not a bad idea for those who want a ring or need internal maintenance at the same time.

We can accept the whole kart and handle the project for you OR you can bring in your clean engine with radiator removed in order to save money.

The one clause I read is that the work must be completed by February 2016 which is smart planning for any racer anyhow.

Regards,

Joey Guyon
Overdrive Motorsports

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