New Ecu flash for Yamaha Viper/Arctic cats 7000 w/POLL

[tmc3bf]

After last flash my 15 Viper cold starts are terrible. Long crank, starts then after 5-10 seconds at 1800 drops to 800 eventually dies. Won't start unless you crack throttle a bit then it starts. If you let off throttle it dies. I have to hold throttle for a couple minutes until it warms up then it will idle on it's own. PITA. Dealer that did the flash said there are no other flashes and you can't go backwards. Stock flash was the best.

 

[cobrajet ltx dx]

After last flash my 15 Viper cold starts are terrible. Long crank, starts then after 5-10 seconds at 1800 drops to 800 eventually dies. Won't start unless you crack throttle a bit then it starts. If you let off throttle it dies. I have to hold throttle for a couple minutes until it warms up then it will idle on it's own. PITA. Dealer that did the flash said there are no other flashes and you can't go backwards. Stock flash was the best.

You described my old 15 viper exactly when I would be in Canada, unfortunately there is no positive fix. Welcome to the club!!!!

 

[tmc3bf]

Sounds like its time to dump it since Yamaha is no help. Really loved the sled until the last flash in March 2019. Last ride of last season was near Lake Vermilion after the flash. Both mornings had trouble with cold starts.

 

[DTJ]

What you're describing with cold starts sounds very familiar to the way mine ran with tight exhaust valves. You didn't have any cold start issues at all before the flash?

 

[twyztid]

My 15 got the flash last April when it was in for repairs for serious starter kickback. I am hoping I don't have starting issues this year

 

[Allan]

After last flash my 15 Viper cold starts are terrible. Long crank, starts then after 5-10 seconds at 1800 drops to 800 eventually dies. Won't start unless you crack throttle a bit then it starts. If you let off throttle it dies. I have to hold throttle for a couple minutes until it warms up then it will idle on it's own. PITA. Dealer that did the flash said there are no other flashes and you can't go backwards. Stock flash was the best.

Sound like tight valves.

 

[tmc3bf]

No cold start issues before last flash. It's on its 3rd flash. Stock flash always started first try. Second flash, supposed kickback flash, my sled would take 2 tries to start, but always started. It never backfired until the 2nd flash was done. Sounds odd that flashing the ECU would result in tight valves. What's involved to check/adjust valves?

 

[cobrajet ltx dx]

Here’s my real world timeline from New 0 miles.
Always had the extended crank on hot restart, would always start cold with a choppy idle from day 1. As mileage increased the starter kick back went from very minimal to more pronounced. Started to develop the frozen fuel relay no start issue around 250o miles. So then I decided to get the flash for the kick back around 3k. Instantly noticed the 2-3 attempts to start initially and then was the nightmare extreme cold start backfire started, it would start initially then drop to 800 rpm and stall.
Then it would attempt to start and backfire with muffler damage. That senecio was a guarantee backfire.
Was flashed again for smoother idle ect but sled continued to not start, backfire ect at times.
For my situation that kick back flash is what I honestly think started my nightmare. There is no way the valves were that tight at 3k because I noticed the sled was COMPLETELY different once flash was downloaded.

Let’s no confuse tight valves causing start issues (that absolutely exists) to Yamaha’s inability to properly setup and enhance there ECU MAPPING for various climate’s.

 

[tmc3bf]

Here’s my real world timeline from New 0 miles.
Always had the extended crank on hot restart, would always start cold with a choppy idle from day 1. As mileage increased the starter kick back went from very minimal to more pronounced. Started to develop the frozen fuel relay no start issue around 250o miles. So then I decided to get the flash for the kick back around 3k. Instantly noticed the 2-3 attempts to start initially and then was the nightmare extreme cold start backfire started, it would start initially then drop to 800 rpm and stall.
Then it would attempt to start and backfire with muffler damage. That senecio was a guarantee backfire.
Was flashed again for smoother idle ect but sled continued to not start, backfire ect at times.
For my situation that kick back flash is what I honestly think started my nightmare. There is no way the valves were that tight at 3k because I noticed the sled was COMPLETELY different once flash was downloaded.

Let’s no confuse tight valves causing start issues (that absolutely exists) to Yamaha’s inability to properly setup and enhance there ECU MAPPING for various climate’s.

Totally agree with Cobra. Never had issues until Yamaha updated ECU flash. My has got worse with each flash.
Doesn't make sense that it starts and runs perfect on high idle for 5-10 seconds then drops to 800 and dies. That's not valves.

 

[cannondale27]

We're either of your sleds checked for having a out of phase ignition reluctor on Stubshaft? Have seen that more than once.

 

[tmc3bf]

How do you check for that?

 

[cannondale27]

You remove the Stubshaft and make sure the mark on gear and shaft line up.

 

[cannondale27]

Here is a picture of one that's off. The line on gear should be lined up with the flat spline in shaft

 

[cannondale27]

Great thread by Upton here.
https://ty4stroke.com/threads/viper-wont-start.157039/

 

[tmc3bf]

Here is a picture of one that's off. The line on gear should be lined up with the flat spline in shaft
View attachment 150841

Thanks for the pic Cannondale. If the reluctor was out of phase wouldn't that cause it to run like crap all the time. After it comes up to temp it runs normal.