Anyone with Evo flash still get kickbacks?

[cannondale27]

Same here IF I get confirmation from EVO that no one has had codes or broken starters with the 14 based flash. I will wait as long as possible for Yamaha to provide a proper wire harness and ECU. Rolling the dice. We have to remember there are very few EVO flashes as percentage to Yamaha reflashed units out there and last year was a very low mileage year for most of us.

 

[PAvector]

I have a EVO 2.5 flash and havent had any issues with kickbacks or hard starting, I don't remember if the base file was 14 or 15. Idle RPM still vary a little.

 

[grizztracks]

I have a EVO 2.5 flash and havent had any issues with kickbacks or hard starting, I don't remember if the base file was 14 or 15. Idle RPM still vary a little.

But did you have any start issues before the EVO flash?

 

[PAvector]

But did you have any start issues before the EVO flash?

I had hot starting issues before, throwing 2 codes a lot. Never had any big kick backs previously. Had one major backfire a 5mph that stall the engine previously.

 

[Mtnviper]

Just some food for thought here. I would assume that kick back during cranking could be caused by advanced ignition timing during cranking. In my case, I'm running an EVO tune for premium fuel which means in theory there would a reduced chance of kick back due to the higher octane fuel.
It may help explain why EVO flashed sleds (and possibly turbo sleds) may not notice kick back.
(just throwing it out there )

 

[cannondale27]

Another theory is the massive voltage drop and recovery is enough to trigger ignition.

 

[Mtnviper]

Yes, I've been following that thread as well and there certainly could be something there.

For those who are experiencing kick back, fuel volatility would be easy enough to rule out by simply filling the sled with premium fuel. If it goes away then we'll know where on to something.
It could also help explain why some have kick back while others don't, as fuel volatility can vary from region to region or even at different fuel stations locally.

If changing fuel does fix it and you want to run premium, I probably would get the ECU flashed for premium fuel. Then the timing curve will be set up for best performance when using premium.
Another option would be to try mid-grade fuel with a stock ECU to see how it works.

 

[grizztracks]

This engine was designed by Yamaha to run on 87 octane. I would think if the octane level of the fuel was the issue we would have seen the same problems in the Nytro, Vector and YXZ1000. It's not fuel........it's engine control.

 

[Mtnviper]

I'm not disagreeing with you grizztracks, I'm only offering this up as a diagnostic aid. Yes I'm aware that the engine is designed to run on 87 octane and the differences between the two ECUs and schematics.

The key to a successful diagnosis is repeat-ability under a controlled environment. By changing fuel we are simply changing the controlled environment, if it makes a difference then we know that it could be cranking ignition timing related. Now as to why that is happening is another story. It is indeed possible that an excessive voltage drop could be causing the ECU to alter cranking timing or to reset.
That said, if changing fuel does actually stop the kick back and I wanted to go ride, I would change fuel until the root cause is found!

 

[grizztracks]

Mtnviper, I understand your logic but the bottom line is that none of the full Yamaha versions have an issue with kickback regardless of fuel octane levels. I actually don't know of any other engine designed for pump gas that can't handle the relatively small change in octane levels. I'm also not a fan of running higher octane fuel with a mapping change to compensate for it. To maximize performance with higher octane fuels there also should be an increase in compression for the fuel to burn properly. Running higher octane levels than recommended usually results in diminished performance.

That being said, I guess if I had issues with kickback and it could be reduced by running higher octane fuel I'd probably do it.

 

[RTX]

14 viper rtx
I put about 15000 miles on the sled With 14 Factory flash.
i had horrendous hot start issues and some cold start issues. It actually backfired so bad a few times that it blew a hole in my factory muffler.

Had it flashed to the updated 15 flash. I put about 1200-1300 miles on this flash. This resulted in better overall starting but now i had poor idle and also experienced 1 episode of starter kickback. One other thing i noticed was excessive popping out the exhaust when letting off the throttle

Had the ecu reflashed by EVO to stage 4.
I had the chance to finally put some miles on it this weekend
Sled starting is not as consistent as the 15 flash, but it starts every time provided i just keep the key turned until it is started. Some times it starts real fast. Some times it takes 5-10 seconds. Just keep the key turned and it always starts.
The idle is noticeably smoother/better . Performance is improved. Popping out the exhaust when letting off the throttle is still there but not nearly as bad as before. You almost have to be listening for it to hear it.
Fuel mileage has decreased by 2-3 mpg but that might be because of the loose snow and the fact i had it pinned the entire weekend. Lol
No signs of a kickback in 350 miles.
For now i am a believer this flash works

 

[NOS-PRO]

Just got off of the phone with Jim from EVO. His flashes have had zero issues with kick-backs.

Jim says they are still flashing Viper ECU's along with Sidewinder ECU's.

I am here to say my Viper never ran better and everyones Viper I had EVO flash their ECU's, not one problem.

 

[cannondale27]

Just got off of the phone with Jim from EVO. His flashes have had zero issues with kick-backs.

Jim says they are still flashing Viper ECU's along with Sidewinder ECU's.

I am here to say my Viper never ran better and everyones Viper I had EVO flash their ECU's, not one problem.

Terry ask him how many 14 based flashes were sold. Good to know what we are talking about number wise.

 

[NOS-PRO]

Terry ask him how many 14 based flashes were sold. Good to know what we are talking about number wise.

I will find out....

Jim, along with everyone at EVP have been super busy. I will find more out soon.

I'm going off a whim here as my ECU was the baseline for the EVO flashes which was a 2014 based flash... When the flashes were made, I had my 2014, 2015 re-flash and 2016 ECU's there to find out what Yamaha/Cat changed. We knew the kick-backs did not come from the 2014, so that was the baseline of the flashes.
My guess would be 95% of the flashes were based off of the 2014. Was there a 2015 based flash? Could have been....but very small number

 

[cannondale27]

I will find out....

Jim, along with everyone at EVP have been super busy. I will find more out soon.

I'm going off a whim here as my ECU was the baseline for the EVO flashes which was a 2014 based flash... When the flashes were made, I had my 2014, 2015 re-flash and 2016 ECU's there to find out what Yamaha/Cat changed. We knew the kick-backs did not come from the 2014, so that was the baseline of the flashes.
My guess would be 95% of the flashes were based off of the 2014. Was there a 2015 based flash? Could have been....but very small number

Yes he advertised 14 or 15 based flashes. We know 14's had kickbacks also. A real number of flashes sold is important since we know many of us never had a kickback with either Yamaha flash. % is not accurate enough if we don't know how many Evo flashed. We are all busy. It's a simple question.