Keefer Kuestions 11-13-17
Kris Keefer

Lots of assistance here!



First off thanks for everything you do, your a great resource for all things dirt bike. I just read your review on the VP T4E and was curious how it compared to the U4.4? I run the U4.4 in a stock 16 CRF450 and it makes an unbelievable difference. I am now installing a 13.5:1 piston, would one fuel work better than the other?




The VP U4.4 is a dirty fuel and will gum up some internal parts. I recommend using T4E as it is a clean fuel and will give you better throttle response and pulling power. 


U4.4 might be a little better on overall peak horsepower, but T4E will burn much cleaner inside your engine.. 




Love your podcast on the shootout and the living with series. I am curios on your thoughts on the choice of bars that you feel work the best for this bike. I have been running the Renthal 604 Fatbar which by the numbers is almost identical to the stock 7/8 971 that comes on the bike. Do you think that Fatbar is too stiff and can cause armpump and a stiff feeling.

Curious if you’re planning a handlebar info session on a podcast.



Fat Bars are slightly stiffer than a Pro Taper Evo bar. I run a 827 bar when I use Renthal products a I like a lower bend. 


If you're looking for the most flex the PT EVO SX RACE bend is the way to go. I might do an handlebar podcast, but will wait until after 250 shootouts are over. 






I was working with my son setting up his bike and when I rode it I noticed a very top heavy feeling on the lean in entering corners. Is this a common complaint on this bike. I do have the 2017 hangers and motor mounts. Running about 105mm of sag. He’s 6’ 150lb. (I’m 5’ 10” 190lb). Stock springs but revalved. Renthal 997 bars. 


Also I know it came up at some point, the YZF foot pegs are definitely higher than other brands. I secure the bikes in my trailer using the pegs and I guess they are a good 25mm further off the ground. 



Matt Cempa #18



Never really had complaints on footpeg height with this bike before.. 


However, if you want a little more “easier flop” on lean in try using the radiator lowering kit from DR.D. This helps the bike lean in corners slightly better and it could be with a try. I liked them when I used them as well.


If you want to run 102mm of sag this could also help cornering too. Make sure your fork height is 4-5mm up in clamp.  




I'm driving to So Cal right now with Eric Phipps (Works Connection) for the MXA ride day on Wednesday and we're discussing the best options for fixing the 2016 WPS 4CS forks. I have 2 2016 KTM 350's (SXF & XCF). I sent the SX suspension to Pro Circuit and have had mediocre results at best. My question for you is who would you suggest for the XCF? I've read a lot about ESR but found his lack of website and online presence concerning. I'm not saying he needs a state of the art website but didn't want to invest in someone that is potentially a shit show. Everything I read about Earl seems great but you know how the mags will stroke a vendor. Thus, is ESR worth trying out or is there someone else that can fix the 4CS nightmare for off road applications. Of course Eric is telling me to pony up for a set of cone valve forks!

Thanks in advance for your honest advice,
Taude Stevens




Well.... Eric is right... LOL...But... I have had great luck with StillWell Performance in Arizona. I have tested two separate bikes with is fork setting and loved it. He is very well known for getting that fork and KTM's in order for the average off-road guy. Try looking them up online and Alan over there is a great dude! 


Have fun at the ride day! 




Hey Kris,


Thanks for looking at this. I am 6’1, 190 lbs. I am looking into purchasing a 450. Looking between 2014-2017...i grew up racing and the last bike I had was a 2007 kx 250f..I’m 32 now and thinking of getting back into it, stopped because there wasn’t much of a place to ride around here (mt.holly,NC) I saw philthy phil and Justin hill bike on the road couple weeks back and got the itch again. Anyway, last time I stopped at b class, I imagine the bikes are so much better than before, can you help me with a bike suggestion. I used to like the feel of the Suzuki turning and comfort but like I said been out the game for awhile. Not sure which way I should be looking.



Josh McClure 




If you're looking for a bike to corner, the 2017 Suzuki is great, but the fork is a nightmare. 


My suggestion would be to look into a 2017 Yamaha YZ450F or a 2017 Honda CRF450R. Both have spring forks and are great machines! You're 6'1 stature fits a Yamaha better and it has enough motor to pull you around. 


The Honda corners better and has a great engine, but is slightly less stable at high speeds. Look into one of those bikes! 


Let me know which one you get! 




Hey Kris,

I’ve got a couple of bikes and it was recently brought to my attention that the Pro Taper Twister throttle tube changes the position of the throttle grip outward up to a half inch (in comparison to the centerline of the handlebars).  Have you experienced this?  What do you use for throttle tubes?  I loved the smooth action of the Twister but cant deal with the position.  Any advice?


Thanks, Everett




I always am a stock throttle tube guy. If you keep fresh tubes on hand I never really have a problem with them. It's tough going to an aftermarket tube because you're never really getting exact OEM specs. I am big believer in OEM specs, especially throttle tubes. I don't like aluminum tubes as they are hard on the hands (landings) and create more friction (while turning) to me. Yes, they are tough, but a plastic tube isn't that expensive if you have a 10,000 bike If you crash hard enough to break a plastic tube, chances are you are not going to finish the moto anyway. If you’re an off-road guy, an aluminum throttle tube makes sense. 





Hey Keefer , first off thanks for all the work you do and info you bring us on all bikes and info on products that are out there!
So I'm an east coast Georgia guy with a few sand tracks and deep loamy plowed tracks that are rutted. I ride a 12 kx250f and have the suspension done by race tech (had to throw that in there because I know you hate that sff spring fork). I race the 30+ open class and am a mid pack guy (fast C slow B class, jump all the jumps easily). I'm wondering what the best motor mods I could do to it and I'm open to anything, big bore, cams, exhaust, etc... my bike is bone stock minus the suspension. My biggest problem now is having to downshift so much going into turns where all the 450s can just pull the same gear all the way through that is where I loose all my time and once we get through the turns I have to send it to my edge on the jumps and straights just to catch back to where I was. I should prob add I weight 155 5' 9". So I guess in typing this I think I'm looking for more bottom pull and hit because I'm good at carrying momentum everywhere else but abuse the clutch and shift like crazy to pull the deep tracks corners. Any help would be appreciated!
In addition I know the easy answer is get a 450 but I am on the lighter end I think and have always suffered from arm pump no matter what I do so I tried a 450 for a little while but just felt way to sketch. -Dylan




It sounds like the easiest way to get more torque would be to install a 270cc kit in your machine. This would give you extra bottom end so you can roll out of corners more 450cc like. 


Cylinder Works makes a great big bore kit that I have tried and it is very fun to ride. Doing that and putting a set of Hot Cams in her will help the top end as well. Go to Cylinder Works website and look around, but I know the 270 kit kicks ass. 







Obviously suspension settings are a bit personal preference but I wanted to pick your brain about anything you had found with the 16/17 CRF250 in general. Appreciate your time as well as your podcast, keep it up. -Joe




Besides suspension going to a Moto Tassinari air boot really helps this bike's mid range power. If you can still find them….


Here is a suspension setting to try...




Outer Chamber 9PSI

Inner Chamber Stock to -1

Compression +2 Compression clickers

Rebound -2 clickers 


Shock: 105mm Sag


Everything else should be near stock settings on suspension. Hope this helps…





Hey Keefer, 

Quick question. Do you like a 110 rear compared to a 100 rear for a 250f? I have an 18 yz250f and would like to try a 110. I noticed the ktm comes stock with one so I’m thinking/hoping it wouldn’t pull the power down. 


Thanks for all your content man. You’ve helped me numerous times. -Justin




Yes, you can do that, but it will hurt power slightly. Some notice it some don’t. Depending on how picky or technical you are, you might not even notice it. I run 110’s when I run an aftermarket ignition on a 250F that comes stock with 100 rear sizing. There is a reason manufacturers run 100 rear tires an that is mostly do to weight and horsepower.  





Hey Keefer just wanted your opinion on a decision I have to make soon I will be purchasing a new 2018 YZ450 and with you knowing Sutherlin so well I figured you were the best to ask. I am going into 450B in WORCS and will be racing select  BIG6 races and also the SRA GPs at Glen Helen. I practice in barstow on tuesdays and Glen Helen on thursdays. My question is if you were in my boots with this schedule would you purchase the 18 450 or the 450X. I am a rider that tends to gear his bike tall and have less hit and a power range that pulls longer reducing shifting. And dropping 2k after buying the bike is no issue I am just trying to get a good base so any information and opinion would be greatly appreciated.



Kristopher Smith



Sorry for the delayed response.. 


Hope this gets to you in time, but go with the 450F.. Gary would rather race the 450F all year than the FX. Trust me! 


The F has more power and is lighter. Buy yourself an 18 inch rear wheel for the F and race it how it is. The FX wiring harness is difficult and the FX feels sluggish. The FX transmission spacing is also not as good as the F for what you are doing. 2nd-3rd gear spacing seems way off and you end up compensating with sprocket changes. 


You will LOVE the new 18 YZ450F.. 


Let me know when you get it and ride it! 





I bought the 18 and just noticed it doesn't have the steering stabilizer. Recommendations on if I should use one and if yes, 20mm or 24mm? -Tracy




We tested with it and without it and it didn't make that much difference on straight line. It helped a little on de-cel coming into corners.  


If you are referring to what offset to go to, I would ride with the stock 22mm offset unless you're riding Hare N Hound's than maybe a 24 would be be the best bet. 


Congrats and have fun..





Hey Keefer, Long time fan through the Dirt Rider Articles and now on the podcast bandwagon . I Purchased a brand new 17 KTM 250sxf and the spoke by the rimlock comes loose after any amount of time on the track , I have read through most of the magazine articles about it and they all mention it but there isnt really a fix specified. Is therew anything you would recommend. I am a 200lb Longtime beginner rider, it loosens as quickly as a couple laps to where i have to tighten it. Thank you, Rick




Thanks for listening and following our stuff! 


This is common, like you mentioned and the only thing that I came up with is that the wheel is out of true. When my wheel is out of true, the spoke near the rim lock loosens faster than other times. 


I also went to a slightly tighter spoke torque technique and use a FAAST CO torque spoke wrench. Try this and see if this helps.. 


If not go to a another set of stainless spokes and nipples from Dubya. Dubya’s spokes seem to stay tighter over a longer period of time.