2019 Yz450F Tuning

[Sledhead406]

I put together a new set up this year with a 2019 YZ450F, I've installed a FMF Megabomb Header and the GYTR slip on to the bike as well as a C3 intake. My buddy has an identical bike but being an 2018. He recently installed the CR racing intake onto his bike (stock exhaust still) and then seized the piston first ride out. The shop said the engine seized from running too lean due to the intake being installed. He also hasnt messed with his mappings at all. This makes me wonder and also concerned about my current set up. I Haven't touched any of the mapping on the bike, everything in the ECU is factory. Does any one have any leads or ideas as to what i should put these parameters at? or go with an upgraded ECU such as the PR2?

 

[needpowder]

Easy to throw more fuel at it with your phone if you’re concerned. I personally would think there’s a little more wiggle room than that in the mapping though.

Assuming that your buddies bike was in good shape and well maintained that is pretty crazy to me.

 

[M5-]

I'm currently running the hard hitting map on my 18. I'm running the stock exhaust. I really doubt that the piston seized due to the intake, they move a lot of air with the stock air box, the intake is just about preventing snow injestion. Was his bike new or used. Use the app and see what map is truly loaded on there. Sounds weird to me. If you believe the magazine dyno sheets on pipe testing, the stock pipe is super close to any aftermarket pipe for flow.

 

[Sledhead406]

His App says he has 105 hours on the bike and was religiously changing the oil every single ride. I am not sure what mapping he has programmed in his but i know mine is all 0's. needpower, i was going to try the hard hitting map and see how it did. I tried the loamy map for about five minutes and hated it.

His spark plug definently showed the signs of running lean. he also commented that the bike has never ran so good before. he's had it since new.

 

[needpowder]

Interesting. I guess we need to double check his map. I am no expert by any means but it doesn’t seem like the pipe and intake alone with all zeros would make it that lean? Possible though.

 

[M5-]

If its 105 hours of snowbiking then really all bets are off. I try not go over 100 on a cylinder. At 90 hours mine needed a resurface

 

[JimBridger]

I've ran a c3 intake and a cr racing intake with this tune. The c3 does seem to run leaner for whatever reason. It also steams worse and I worry about throttle body icing because of that.

 

[Chadx]

... and I worry about throttle body icing because of that.

What are you referring to as throttle body icing? Like carb icing? Never heard of that with throttle body as they don't have or need a venturing like a carb so no sped up and compressed air that causes internal icing. Something else? Like melted snow dripping straight down through your pre filter? Just trying to understand your concern before answering. Thanks. I've been running a c3 intake on my 2020 yz and haven't had any concerns. Snow would fall straight out the bottom if it got in there but with engine and radiator blanket/guards, I don't think much can get in there. Pre filters are pretty water resistant so water just beads on top. But if concerned, at the end of the day back at the trailhead, just a quick check to ensure no snow stacked on top of the prefilter. Meaning clear it off before it melts.

 

[jrusher]

I ran my 18 with the cr intake and -3s on fuel and +3s on timing right from new no issues. After 30 hours piston/cylinder are still like new. I doubt it siezed from that intake

 

[eric82930]

Probably was a cold seize. Even with a tstat they need to be warmed up. If it was even slightly lean the piston will swell faster than the cylinder.

 

[s.e.xtreme]

Ive got a 19' yz and just getting started on this new tune thing? what is the hard hitting map you guys are referencing? ive done searches and cant seem to generate any info? im running stock exhaust with cr intake. no problems at all.

 

[M5-]

Its in the app

 

[cbc76am]

Either water got past the filter and washed out the oil seal on the rings (most likely) or cold seize due to lack of engine jackets, radiator block offs if it was waist deep, or thermostat. Mods can't swing it lean enough to sieze. That doesn't even make sense on a 4 stroke. Lean would cause excessive heat and warp valves and seats, not sieze the piston. Most common is too much ignition advance causing the piston to crack in half on Yamahas. Don't go past +4.