The Yamaha YZ450F has been widely respected as a powerhouse of a machine for more than a decade now. You’ll be lucky to find anyone on earth that could honestly call one slow. Since turning the engine backwards in 2010 the YZ has made big horsepower but Yamaha has had some trouble taming that power to make it useable. They introduced the 2024 Yamaha YZ450F Power Tuner app to enable punters to do it at home so we thought we would do out own Yamaha YZ450F Dyno test.

In the past the power has been very abrupt and has made the YZ feel like a big bike to handle and has required a lot of muscle to hang on to. The engine has been very revvy in the past so that when the rear wheel would break traction the engine rpm’s would spike making keeping the bike pointed straight down the track very difficult. In 2023 Yamaha gave us a new model and promised us that it would have the most useable power output of any model.

They weren’t wrong and they only made that power better for 2024. If you have been following along for the past few months and have read our previous tests on the 2024 Yamaha YZ450F, then you’ll already know we have stated that the YZ power is the best overall out of any production bike we have tested. Remember we have tested every motorcycle imported to Australia since 1975. It’s a big statement and one that anyone who has thrown a leg over the new YZ will totally agree with.

Being that the 2024 YZ450F power is so impressive and with Yamaha releasing their new updated 2024 Yamaha YZ450F Power Tuner App the aim of our Yamaha YZ450F Dyno test is to see how much power it makes in stock form. Then use the Power Tuner App to tune the most power we could out of it and then also go the other way and see how much we could dull the power down. Like us, I’m sure you’ll find the results surprising.

Stock As A Rock

First up we need to put the YZ on the dyno in stock form to get a base to compare from. To do this we put the YZ in the stock map that it would come with straight off the dealership floor. For this test we used the stock exhaust system and stock air filter.

Before we go into the results I feel it is necessary to mention here that all dyno’s are different and the setup from dyno to dyno can affect the overall horsepower figure. Furthermore this is a Dyno Tech dyno made by a company in Melbourne called Dyno Dynamics. If you spend most of your time reading American press releases then you’ll notice that the horsepower figures here are less as the American’s predominately use a USA made dyno called DynoJet that reads slightly different and generally gives higher horsepower figures. This test is not to compare results against what some guy in the USA claims but rather to compare apples with apples on the same dyno on the same day.

With all that being said I was immediately impressed with the stock run of the YZ. I was impressed but not surprised as I had already ridden the bike and knew the power was very good. In completely stock form with standard mapping the 24 YZ450F made 56.4 peak horsepower at 9500rpm with the torque being above 45Nm between 6000rpm and 9000rpm. The power curve is very linear and progressive with a very little dip in the curve which is no wonder the bike is easy to manage on the track while still producing strong peak horsepower. This is a very good place to start from so let’s see if we can make the YZ faster from here.

Can It Go Faster?

The standard mapping is very good so improving on it was a tough job. Other makes and models of 450’s are very easy to make better with as little as twenty minutes on the dyno. With better mapping they can produce five or six horsepower but this was absolutely not the case with the YZ450F. After two hours and countless changes back and forth I was only able to better the standard mapping by 0.6 of a horsepower.

The map I produced follows very much the same curve as standard but I was able to increase the torque throughout most of the rev range which ultimately resulted in the increased overall power. The tricky part with this bike is that it actually comes mapped on the rich side and there is a very fine line between how much you can lean it up, too far and the bike drastically drops in power. To get the extra torque out of the engine I had to lean up the fuel mapping while advancing the ignition curve but the trick was not to advance the ignition timing too far or the bike became too aggressive to ride on the track.

I happened to mention to a friend of mine who maps high end ECU’s for many race teams that I was trying to get more power out of the stock YZ450F and he laughed at me and said “good luck, they are mapped very well standard”. At the time I thought it was an odd comment but after spending countless hours mapping the YZ I have to agree with him. It’s a very hard task to beat the stock map. Lastly, if you are really chasing more power out of your YZ450F then I can tell you an Akrapovic exhaust system with a few air box mods to increase air flow and then a remap is the way to do it, but the power becomes much more aggressive.

Slow Down

The biggest difference I could make with the Power Tuner App is how much I could slow up the YZ. This is a good one for anyone that finds the power of the YZ450F too much. Quickly and easily within a few minutes you can program in a map that drops the power of the YZ from 56.4hp to 51.4hp. Just with a simple map you can knock 5hp out of the bike which makes a big difference when you the bike on the track.

The torque is drastically decreased and while the engine still revs to over 11,000rpm it produces nowhere near the top end power of the stock map. To achieve this I increased the fuelling as far as the app would allow and retarded the ignition timing as far as the app would allow. This map would be excellent for a lightweight or beginner rider as the revs climb much slower and is much less responsive.

Final Thoughts

The standard mapping on the 24 YZ450F is very good. The guys at Yamaha have clearly put in the effort to get this mapping right. We see time and time again that the mapping we get in the bikes coming to Australia is just not right and some simple dyno work can improve the power and fix them quite easily. I have to say I was impressed with how well the YZ is mapped from standard but also disappointed because Yamaha have left us tuners not a lot of work to do here.

To get any more power out of the YZ450F you need to start looking into other modifications like the cylinder head, air box and exhaust system then remap the ignition to suit. However the power the YZ450F produces standard is very good and it does a very good job of getting that power to the ground. So all those mods aren’t really necessary unless you are an elite level racer and even then it’s probably still questionable.

Words | Mat Boyd

Photos | Mitch Lees