2010 YZ450f Yoshi rs-4 map questions?

I looked all over for a map here and could not find a map for a stock engine, k&n airfilter and a complete yoshi rs-4 exhaust, no db reducier, no spark arrestor. I'm just looking to keep the power as close to stock with out any loss for use on SX track. Any knowledge would be helpful.

Forgot to add at sea level, temp 80.

I would try the Jay Marmont map seems to be a favorite on here. You may also want to try some of the yamaha factory maps too. Just play around until you find something that suits you. The stock map may not be all that bad either.

I agree, the jay marmot map is the way to go, it looks to be suited for a slip on as well. I used it for a long time and it was very aggressive and gave the bike the feeling of a monster compared to stock.

However if you want power close to stock then I would leave the default map, the bike is slightly rich from the factory so the pipe will help lean it out some.

Try some laps with the stock map and your current config and see how it fairs, then load up the jay marmot map and see how you like it.

I've run the stock map and the less hit map with a Yosh RS-4 and they both work really good. When the snow finally clears the broad map and marmot map are the next ones I'll try. Try all of the maps and decide which one you like.

I actually use the more top end map with the pipe and I found I liked that one the best, pulled a lot harder up top and longer as well... which is where the bike needed it most.

Hey guys thanks for all the help, I figured it was running a little rich due to that I have to pull choke to get it to start after a stall(read about slightly cracking throttle trick), but thank you again for all your info. Can't wait to give the Jay Marmont a try.

Hey guys thanks for all the help, I figured it was running a little rich due to that I have to pull choke to get it to start after a stall(read about slightly cracking throttle trick), but thank you again for all your info. Can't wait to give the Jay Marmont a try.

they are too rich for hot starts for sure but just know nothing you do with the GYTR tuner can ever change the start a/f ratio....I wish but it doesn't. Good luck, hope you find something that suits!

i have the yosh rs-4 with the vortex x10 ecu,the power i get out of that box is out standing.,tried all the other maps with the yam tuner,works good,but cant compare to the vortex.IMO comes with 10 maps and you can tune each map.

To Jim, and others with the power commander, etc. I've heard the Yamaha tuner can't match the specific tunability of the other high end tuners, but how about a little guidence. I've seen power commander screens that show the bike is very rich with the stock pipe and the tuner resets everything leaner. What do those screens look like with a FMF, etc on it? I know we can't match it so I don't think you're giving away protected information. I would just like to know if we could approximate those settings. I currently run the Jake Marmott map with a FMF full system on my bike and it feels great. It's quite a bit richer than stock but people without a pipe like it too. How could that be?

To Jim, and others with the power commander, etc. I've heard the Yamaha tuner can't match the specific tunability of the other high end tuners, but how about a little guidence. I've seen power commander screens that show the bike is very rich with the stock pipe and the tuner resets everything leaner. What do those screens look like with a FMF, etc on it? I know we can't match it so I don't think you're giving away protected information. I would just like to know if we could approximate those settings. I currently run the Jake Marmott map with a FMF full system on my bike and it feels great. It's quite a bit richer than stock but people without a pipe like it too. How could that be?

I may be wrong on this however a carbed engine is dependent on engine vacuum to draw fuel into the cylinder and is sensitive to vacuum changes from modifications. An EFI bike is not as sensitive due to fuel being sprayed electronically onto the back of the intake valves, so changing exhaust and air flow doesn't affect a/f ratio as drastically and less changes are needed for the engine to perform correctly.

I may be wrong on this however a carbed engine is dependent on engine vacuum to draw fuel into the cylinder and is sensitive to vacuum changes from modifications. An EFI bike is not as sensitive due to fuel being sprayed electronically onto the back of the intake valves, so changing exhaust and air flow doesn't affect a/f ratio as drastically and less changes are needed for the engine to perform correctly.
You are correct to a large degree. Carburetors can naturally compensate for changes in air density and such TO A DEGREE because their fuel delivery is dependent on the strength of the vacuum signal that raises fuel from the jets. Fuel injection in its simplest forms will deliver fuel according to its programming regardless of any conditions. More sophisticated systems add devices such as temperature sensors and barometric pressure sensors to give the ECU additional information with which to modify fuel delivery, still according to the unit's programming.

The YZ450 EFI system is reasonably sophisticated, having sensors to gauge the temperature of the intake air, barometric pressure, intake manifold pressure, coolant temperature, throttle position, and RPM, but the unit is still only going to perform as well as its programming will allow it to. Carbs, of course, only work as well as they are jetted. In terms of fuel economy, to really excel at this, an EFI unit should have an oxygen sensor.

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