Yamaha didn’t change the YZ250F very much for 2020, but we did manage to get some added on-track information on Yamaha’s latest YZ250F and get you some feedback just in case you missed it in 2019. Below are some notes that should be taken into consideration about the changes Yamaha’s did make in 2019 and how the new 2020 YZ250F rides on the track. We will also lightly compare how the 2020 compares to the older 2018 model just in case you’re coming off of an older Yamaha YZ250F for comparison sakes.
Also, just in case you missed the bold italics above, we say “very much” because some other media outlets are saying that NOTHING has changed with the 2020 YZ250F, but there is one small change and that may have been over looked. The filter element now has a rubber grommet to keep the element in place under the harmonics of the motorcycle while running. The 2019 filter element didn’t seal that well, but with the updated grommet the 2020 seals much better. It’s not much, but it’s an important piece to a problem that the 2019 Yamaha had.
2019 Changes:
Yamaha kept the reward slanting engine design (for 2019 the engine is slanted forward 1 degree from the 2018) that already worked so well on the last model and made some changes to make it even better. Starting by adding electric start, Yamaha is the second Japanese manufacturer to have an e-start 250F motocross bike. The exhaust port shape was slightly modified so it transitions to the head pipe (which shape has also been changed to accommodate this) better and has increased the flow rate. Also in the head, Yamaha has increased the intake valve lift, and slightly changed the angle of the exhaust cam. The final changes to the new head are larger lifter buckets and slightly stiffer valve springs. Underneath the head, the piston crown has been increased, which has bumped the compression from 13.5:1 to 13.8:1.
The throttle body on the 2019 changed from Keihin to Mikuni. It is 44mm and has a 12 hole injector. Also different on the throttle body is the cold start (choke) which now has to be pushed in to be activated and is deactivated by fully closing the throttle. Along with the engine changes and new fuel system, the ECU settings have been updated. The new dual electrode spark plug’s cap now has a finger holder keeping the cap firmly in place. The transmission side of the engine has also received key changes including a heavier duty clutch. What makes the clutch stronger is larger plate diameter, 6 clutch springs (one more than last year), and thicker steel plates (which in turn reduced the number of friction plates from 9 to 8). The transmission gears have also been updated and are using a high impact steel.
The new e-start is a compact, sits behind the cylinder, and drives the clutch basket directly. The 1.5 pound lithium battery sits under the rear of the seat and has a capacity of 2.4AH and 13.2volts. The amount of power the YZ 250F needs to generate has been reduced because of the addition of the battery which means there is less resistance on the stator/engine.
The frame on the 2019 has been majorly changed to make the bike feel more nimble on the track. The frame rails that go around the gas tank/air box are now straight where last year had more of an S shape. Other parts of the frame have been changed from forged pieces to extrusion aluminum, and the engine mounts have been changed from steel to aluminum. The material at the swingarm mount have been increased front to back and narrowed side to side, making the side of the frame flatter at the swing arm mount. The steering head has also been moved forward 6mm to help with stability.
In the past there have been comments about the seat height and width of the YZ 250F. Yamaha has changed that by making the seat slightly flatter, shorter, and narrower than last year’s model. Along with the seat, Yamaha has narrowed up the plastic where the rider’s knees contact the shrouds. The new shrouds have the air ducts integrated into them (same as 450) and the whole top part of the shroud no longer has to be removed to service the air filter. The air filter cover now only needs one Dzus fastener to be removed for access to the air filter which is no longer held in by a screw, instead it’s held in via rotating clips.
Yamaha tried to lighten the bike in 2019 up by using thinner, higher strength material for the handlebars, and also using lighter rims. To help with stability, they increased the surface area of the wheel collars where they contact the fork lugs and added more material to the rear collars. The KYB forks use new internals including a new piston, cylinder, mid speed valve, pressure piston, and stiffer spring rates (from 4.6N/mm to 4.7N/mm). The shock reservoir volume has been increased by 30cc and the coil spring now has less winds, is made of a thinner material (lighter), and the rate has changed from 54N/mm to 56N/mm.
On The Track With The 2020 YZ250F:
The 2020 YZ250F has great torque and pulling power down low, but doesn’t quite have the top end pulling power like other bikes in its class. The YZ250F is so good at low rpm that it gives me the sensation that I want to ride a 250F full time. It’s that much fun! The Yamaha pulls hard out of corners and has a huge amount of bottom to mid range response that most will appreciate. There is enough meat coming out of corners that a wide range of riders as well as abilities can be left with the decision to leave it in second or third gear through corners. It’s a very vet rider friendly machine and gives the rider that excitement that we all look for in a bike. What is the downside? It does have more engine braking than the KX or CRF and I would like more top end pulling power through second and third gear. We worked on a different map to increase top end and also decrease engine braking. More on that below.
The firm feel of the 2020 chassis makes the bike feel planted and have a positive front end feeling through corners. Where the 2018 kind of felt lethargic/slow to react to the rider, the 2020 feels slimmer and more nimble (from the swingarm pivot forward) yet has a better straight line character on fast choppy tracks. The easiest way to describe the way the 2020 feels is that it has a fun cornering character with a confidence inspiring straight line feel. The 2020 YZ250F isn’t the leader of getting in and out of corners the quickest, but the planted feel in which it comes with is calming to any rider. The chassis still has a pitching (off throttle) sensation, but with a small change to the ECU, this pitching feel can diminish. The beauty is that if you want engine braking with a heavier front end feel, the Yamaha can give you that or if you want a lighter front end feel with a less heavier front end feel, simply going to the “Keefer Free Feeling Map” can give you that as well. Again, to me, this is a very well rounded chassis for a wide range of riders and abilities.
The 2020 KYB SSS fork is still the best fork out on the market. With the chassis changes Yamaha made in 2019, the KYB fork compliments those changes wonderfully. The fork does not dive as much on de-cel and stays up in the stroke more (especially with the KK map installed) than the 2018. The KYB fork does move in the stroke, but going 1-2 clicks slower on the rebound helped calm the front end down on g-outs or jump faces. Our lightest test rider liked he stock rebound setting on the fork, but if you’re slightly heavier going slower will be the better way to go. The shock likes to be set to around 104-105mm and it complimented all three riders that we used in this test. We set the baseline sag of 105mm to our middle weighted rider (170 pounds) and the other two riders (150 pounds and 195 pounds) thought the bike was balanced enough for them to push around the track. Traction to the rear wheel is apparent on the Yamaha when giving it the berries out of corners and it’s really difficult for the rear tire to step out coming out from a rut. On de-cel the rear of the 2020 Yamaha doesn’t have a vague light feel, which sometimes could leave you with that rear end “sliding out feel” and then that “oh shit” sensation like the 2018 version had. The rear end of the 2020 YZ250F feels heavier/planted (in a good way), which gave me the sensation of a more connected throttle to rear wheel feel (AKA, meaning a more planted/heavier feel).
Stop with the Yamaha feels fat excuse. Every time I hear this I tell people “go measure your KTM and measure the Yamaha (at the shrouds) and get back to me”. Sitting on the 2020 YZ250F feels just fine because I feel more upright than “inside” the machine. The whole machine feels slimmer and flatter than the 2018, which to me will fit larger sized riders just fine. You will have to go with a stiffer foam after 10 hours or so, but that is an easy fix by calling Guts Racing. You can also go with the bar mount in the forward hole turned back if you need a little more cockpit room. I have tried this position and have come to like this rider triangle feel. The 2020 Yamaha YZ450F will come standard with this position, so I better get used to it.
I really felt that the 2020 Yamaha YZ250F could benefit from a free-er engine feel on de-cel so I worked on a map to try and achieve this. This “Keefer Free Feeling” map below gives you less pitching on de-cel coming into the corners and also made the Yamaha feel lighter through mid-corner, which helped cornering as well as change of direction. I felt like I could give up a little amount of torque that the Yamaha has to achieve this and that is what you will find when going to this map. You will get slightly less torque, keep that great mid-range pull as well as slightly increase top end. If you want to also sacrifice a little torque feeling and increase the second and third gear pulling power (with the same amount of engine braking the stock map gives) go to the “Hard Hitting Map” Yamaha has pre-programmed on your Yamaha Power Tuner App. I use the “Hard Hitting” for my base map and the Free Feeling” map for my secondary map.
Bridgestone X20’s come standard on the 2020 Yamaha YZ250F and although I didn’t like them on the YZ450F when I tried them they work well on the YZ250F, especially on front tire lean angle. I like that you can initiate your lean early on the font tire of the X20 and it will give you a positive feeling underneath you. The rear tire isn’t quite as good on lean angle, but still hooks up in a wide range of conditions. I will say that the X20 has a better carcass feel than that of the Dunlop MX33 tires. I will take a Bridgestone X20 front tire all day over a MX33.
Stay tuned for a settings article over on keeferinctesting.com as well as pulpmx.com for the 2020 YZ250F as soon as we got more time on the bLU cRU machine.
