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gmtech16450yz (motobark)

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About gmtech16450yz (motobark)

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  1. gmtech16450yz (motobark)

    18 yz450f valve clearence WAY too tight?!

    OHHHHH. Geez am I dumb! It's a backwards head! Everyone knows those bumps on the cam CLOSE the valves on a backwards head instead of opening them. Silly me. I'm sorry.
  2. gmtech16450yz (motobark)

    18 yz450f valve clearence WAY too tight?!

    Again, JUST LOOK AT THE LOBES. Put the lobe 180 from the valve stem and then check. The cam lobes in that picture look like the valve stem/bucket is on the ramp of the lobe, not the base circle. I'd rather you didn't look at the timing marks at all and go by eye then to start changing shims at this point.
  3. gmtech16450yz (motobark)

    18 yz450f valve clearence WAY too tight?!

    Steve and Timo said it already, your base circle on the cams isn't anywhere near center. Lining up crank marks is best, but making sure you're actually checking valve clearance in the center of the base circle is your sanity check.
  4. gmtech16450yz (motobark)

    Tale of Two '18 YZ450's and Why You Need the Proper Springs For Your Weight... (duh)

    I figured it out!!! lol. Ok so this spring thing kept bugging me. Like I said, I've been riding YZ's for a long time and it's always seemed like they set up their bikes for roughly a 150lb Intermediate MX rider. That's why I usually can get away with the stock springs, I've pretty much fit their suspension setup demographics for years. The '18 YZ450 is not setup from the factory for a 150lb Intermediate mx'r, IMO. So why are these newer YZ's sprung so stiff??? Then it dawned on me! It's all about weight. What happens when you run a really stiff suspension on a dirtbike? It makes it feel lighter! Just like raising the air pressure in your car or trucks tires makes it feel like it has more power. When the suspension is relatively soft, it makes the bike feel heavy and sluggish. So I can just picture the meeting at Yamaha with all the bigwigs sitting around a table... "Ok, so we aren't willing to risk our dependability to make these bikes any lighter, they are what they are. So how do we make them "FEEL" lighter?" So the suspension engineer jumps in and says "Hey, if we run the suspension stiffer it will make the whole bike feel lighter!" BAM! They nailed it! What does everyone say when they ride the '18 or '19 YZ450? They say it feels much lighter than it is. And it does. Anyone that's played with suspension knows that simply putting lighter springs and damping in a bike will take away some of that "light" feeling. Obviously they've done some amazing things with their "mass centralization" and it of course has to make a difference, I'm not taking that effect away. But was it simply marketing and shootout results that made Yamaha veer away from putting springs in the YZ that would work for the "average" rider? Hmmm.
  5. gmtech16450yz (motobark)

    Tale of Two '18 YZ450's and Why You Need the Proper Springs For Your Weight... (duh)

    My point really was that the stock .51's in the front of these YZ450's are too stiff for most any rider under even 180lbs or so. I've owned YZ's since before they had radiators and at my weight and riding style 90% of the time I can get away with the springs Yamaha puts in them stock. Not on this bike. Like I said, if you're anywhere around 150 to 180lbs, I don't care how you ride, where you ride or what you put the sag at, .51 springs are too stiff. Unless you're Barcia or Reed that is and your normal riding area is a supercross track. And yes, I tried sag settings everywhere between 95 and 110 with the stock springs. You can't turn if the forks don't compress.
  6. gmtech16450yz (motobark)

    18’ 450F spring rate (50 kg / 5.9kg)?

    I just wrote up some info about the '18 YZ450 suspension that might help you or others... Remember on springs and sag it makes a big difference WHERE you ride ON the bike. Yeah, weight matters more than riding ability, but body position makes a big difference too. My buddy at 225 lbs felt my .51 stock fork springs on my '18 YZ450 (book says .50 but I believe they're closer to .51) were way too stiff for him even.
  7. So about a month ago when we were riding, I swapped bikes with my buddy who has an '18 YZ250FX. I have an '18 YZ450F. We both immediately noticed a huge difference in turning and fork action between the bikes. (Ignoring or at least not dwelling on the obvious difference in engine sizes of course.) I felt super comfortable on his bike, and he lost the front end on mine twice and said it felt like I had 30psi in the front tire compared to his bike. Identical front tires at identical pressures (13psi). Huge difference in fork springs, and some amount of difference in valving obviously. So when I got home I started researching the differences between these particular two bikes. Holy cr@p why does the '18 YZ450 use .51 fork springs??? No wonder I had the compression almost all the way soft trying to get the forks to be compliant. The Race Tech calculator specs anything from .44's to .46's for my weight and riding ability which is ~155lbs A class hare scramble/ occasional MX rider. I'd either have to be at least 200lbs or race supercross to warrant .51's in the front of my bike. My buddies YZ250FX had .45's in it stock, no wonder I felt comfortable on his bike! (Disclaimer here... this might be old news for some of you guys, but I've been riding a very long time and even I learned some new things when I dove into the suspension on this particular bike.) So after determining that my springs, both front and back were too stiff for my weight, I sent Dave Johnson at Smart Performance a text to pick his brain a little bit. Before we went into my preferences, right off the bat he suggested .44's or .46's with a 5.4 on the back. Nice! Now I knew I was on the right track and the bike I "thought" was amazing might even be MORE amazing! We ended up texting back and forth, with every text from him I learned more new things! He's a helluva smart guy and knows suspension that's for d@mn sure. I finally decided to go with KYB .47's in the front and a KYB 5.5 in the back. I actually was "ok" with the suspension on this '18 YZ450, I didn't want to go too far and wreck it so I stayed conservative on my spring changes. I also decided instead of doing the forks myself like I've done for decades on every bike I've owned, I'd have somebody that does this stuff everyday for a living do them. Dave ordered the springs, changed the fork springs, machined me a bearing spacer for them, put new fluid in the forks at the perfect levels and also put my shock in his vacuum tank to purge any air, top it off and set the nitrogen pressure properly. I put everything back on my bike and waited for the torrential rain we've been having to stop. So here's where the "Tale of Two '18 YZ450's" comes in... My son also has the identical bike to mine, an '18 YZ450. We both had totally stock suspension at almost the same sag and clicker settings. He weighs within 5lbs of me and his riding style and ability is almost the same, he's a fast A rider. We went riding today, the first time I got to try out the spring change and Dave's work. D@MN! I LIKE IT! So what better way to compare a modification or suspension change than to have two identical bikes to ride back to back? We swapped bikes a couple times today and here's what we noticed... Turn in on the softer sprung bike was WAY better. The bike turns so much nicer it's stupid to think we thought turning was "ok" before. Braking bumps were about the same until I dialed in a little more compression damping on the forks. By adding in some compression, braking bumps on the softer springs were much nicer and far less violent than the stock bike at most any compression settings. Suspension compliance and movement felt much better on the softer sprung bike, the stock bike felt overly harsh in comparison now. So now I'm thinking, "What about when I hit something going way too fast, land too short or too far off a jump or chop the throttle after a 6th gear run in choppy conditions?" We had pretty much ALL of those situations today! Banging bars with my son means whoever is behind needs to take all the worst lines to try to get around whichever one of us is in front. I hit some horrible rain ruts at full speed, sharp kicker jump faces, slammed into rock piles and went into multiple corners WAY too fast. (Normal. lol.) The suspension worked amazingly well for being as "soft" as it felt. One of the most noticeable things between the two bikes was the front end height. I had gotten used to it being "high", not really realizing it shouldn't have been riding that high. My initial reaction to the spring change was I wanted to raise the front end back up to where I thought it should be. I resisted the urge and rode it where I initially set it, all clickers at the center or stock positions, 110mm sag and the forks slid up 10mm where I'd always ran them. I got used to the front end seeming "low" and when I finally rode the stock bike it felt like a Harley!!! Dang, again, why did Yamaha put such strong springs in these bikes? Like I said, this is old news for some of you. Sorry to make you read all this if it was. The bottom line though is IF you have an '18 or '19 YZ450, and IF you're under ~225lbs, and IF you're not a supercross rider, I'd STRONGLY suggest getting those .51 springs out of the front forks. My son will be changing his to the same .47 fronts and 5.5 rear that I did. If you're not a super aggressive rider, you might even want to go lighter than I did if you weigh the same ~155 or so. And having Dave at Smart Performance do the spring and fluid change insured that everything was done perfectly. I'm super happy that we were able to make a bike that has totally impressed me since I bought it even BETTER than it was!
  8. Hey I recently got a new phone and although everything else restored ok from my old phone to the new one, I lost all my Power Tuner maps and race logs. I'm still hoping I can find the data files backed up somewhere in my laptop, but so far I haven't been successful. The app itself transferred fine, it just doesn't have anything in it. Has anyone lost their data and figured out how to get it back? Does anyone know where the app data is stored? And more importantly, IF you can't actually backup or save this data in a safe place, we ALL have to realize that all the maps and race log info we're putting in that app can be easily lost. I'm not freaking out, my best tune is still safe in my bike and I can pull it out whenever I want. The cr@ppy part is I went from writing down all my suspension changes in the back of my service manuals to putting it into the race logs on my phone. Now I don't have any of that data or settings anymore. Boo!
  9. gmtech16450yz (motobark)

    New yz450f no tuner?

    Same thing happened when I brought my '18 home. Went to connect and when it couldn't I took the side panel off and realize there was no WiFi module! I called the sales guy I bought it from, he felt REALLY bad and said "Hold on, let me check on it". He comes back on the phone and said "Yeah, the stupid mechanic left it on his toolbox. I'm so sorry. I'll drop it off at your house on my way home from work tonight." The dealership I bought from was a 45 minute drive from my house. The sales guy kept his word and it was on my doorstep that evening. Must be why he's been successfully selling motorcycles in the SF Bay Area for almost 4 decades. Funny story is when I was calling around looking for an '18, I recognized his voice on the phone when he said he had one. I drove up to buy the bike and we both realized why we recognized each other... I bought my wife's XR250 from him in 1986! Anyway, yeah, the dealer f'd up. It's probably sitting on somebodies tool box or work bench.
  10. gmtech16450yz (motobark)

    '18 YZ450 First Mods and Killer Map

    Hmmm, you're in just a "little" different conditions than I am. haha. What's your altitude and temps? I'm barely at 700feet or so where I ride and it's usually 60-70 degrees even this time of year. The fueling is the only part that could make it harder to start, 2 degrees of ignition timing certainly shouldn't slow down the cranking speed, especially at altitude. The fueling in cold temps and higher altitudes in the stock mapping could be too rich already though. Try putting the 20/3000rpm cell back to zero, and the others around it back down to 1. You might even want to go leaner by dropping all the fueling down, in your situation it might actually run way better. Keep the ignition timing up though, that will only help power and shouldn't effect starting. I'm gonna put this in bold since it's a big deal for everyone to realize... The big "unknown" on this mapping stuff it where your particular bike is running mixture wise with every fuel cell at zero. Just because it's at "zero", doesn't mean the fuel mixtures are perfect. The only way to know that is to monitor the exhaust by-products with a wideband sensor. These systems on these bikes are not closed loop, so the ECM has no idea if the engine is really rich or lean. It's simply based on rpm, throttle percentage, coolant/ambient air temps, and manifold/barometric pressure. It's called a "Open Loop Speed Density" system, it's just providing what it "thinks" will be the proper mixture for the particular inputs it's getting. We have no way of knowing how well the system is mapped as far as compensating for all the different altitudes, temps, rpm's, throttles, etc. It could be perfectly mapped to give the perfect mixtures at one point, and way off in another. We simply have no way of knowing unless we did full blown logging of everything including exhaust. So in other words, just remember that just because you're running on a stock map or a map with all zero's, that doesn't necessarily mean that the mixtures are perfect in every situation or even every bike.
  11. gmtech16450yz (motobark)

    '18 YZ250FX or '18 YZ450?

    YAY!!! Plantguy is back on a dirtbike! And an awesome one at that. Enjoy!
  12. gmtech16450yz (motobark)

    '18 YZ450 First Mods and Killer Map

  13. gmtech16450yz (motobark)

    Taming a 450FX.....

    Did you look at that used one in the link I posted above? It looks like it's in new condition. It's not like you can destroy or really wear one out anyway. This might help too... https://thumpertalk.com/forums/topic/1249756-18-yz450-first-mods-and-killer-map/
  14. gmtech16450yz (motobark)

    Taming a 450FX.....

    https://thumpertalk.com/classifieds/item/1760-yz450fx-throttle-tamer/ (Not mine. I do have a similar throttle tube on my YZ450 already though otherwise I would have bought it.)
  15. gmtech16450yz (motobark)

    2018 supercross yz450f

    Hahahahaha. Yeah 'cause riding a 300 pound trail bike with giant hand guards, kick stand, license plate and carrying 30 pounds of fuel would be awesome on a motocross track. Does it have a horn so you can honk at lappers as you triple over their heads? How many motos do you get in before you have to fill that 5 gallon tank?
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