01' YZ426F - Advice?


7 replies to this topic
  • TeamTech

Posted July 30, 2008 - 02:57 PM

#1

Hey guys, I just joined the site and have already gotten some great tips from reading through the old posts...I'm hoping you guys can help me out.

I just bought a 2001 yz426f and was wondering if there is anything I should/could do to increase performance or prolong the life of my new bike! The bike has barley been ridden, so aside from oil/lube/filter change and checking the valves...is there anything else you guys would recommend I do?

I'm fairly new to the sport so any advice would be great!

  • skthom2320

Posted July 31, 2008 - 08:47 AM

#2

You bought a great, nearly bullet proof bike. It will last you a long time! Just keep the oil and filters fresh and you are good to go!

The jetting was pretty good on this bike out of the box. I rode mine for years with no mods to the carb other than adjusting the jetting for the temps. Make sure you get yourself an extra 40 and 45 pilot (stock is 42), and a fuel screw adjuster (a nice one is the R&D flex jet).

Otherwise do some searching and reading here!

  • BASSic

Posted July 31, 2008 - 01:39 PM

#3

Standard jetting is decent if you ride standard conditions, but if you want some flexibility to adjust according to your conditions, you'll need to rejet.

The JD jet kit (available here at the TT store) comes with custom tapered needles and four main jets for the 426: a 160, 165, 168, and 170. Stock is 162. Lots of people swear by it and say it's the best $75 spent on their bike.

I have it and I'm happy with it. There was no night and day performance difference, but overall it runs better. You may be able to get similar results for less money just by buying the correct main jet and needle that you need, but you get everything with the kit that can work for a variety of conditions. You also get the custom tapered needles.

As for the fuel screw, it's a good thing to have as it allows you to adjust on-the-fly. You just have to be careful what you get though . Most, if not all, of the machined aluminum screws like Zip-Ty, Pro Circuit, etc. don't have the same profile as the stock fuel screw and as a result you have to change your pilot jet to compensate. I have a Pro Circuit screw at the moment and I can turn it all the way in and my pilot circuit is still too rich. I can dial it in properly with the stock screw, it's just a pain to access. Look for a brass screw like the ones from JD, Merge Racing, or Kouba.


The 426 is a very reliable bike. Just read around and you'll learn these are virtually bulletproof. The 2000 had a known issue with the clutch that was fixed in 2001 so you should be OK. I believe all years 426s may be prone to bent shift forks. It hasn't happened to me yet, but there are more than a few reports on Thumpertalk. Valves aren't an issue. I inspected mine when I bought it back in December and they're still within spec, though on the tighter side.

Just change your oil often, usually every other ride or every three rides. Stay away from the OEM brass mesh filters for the 2001 426 and invest in a high quality Scotts stainless steel reusable filter. They're easy to clean and filter better than the brass mesh or paper filters. As for the type of oil to use, everyone has their own opinion and there are many oil debates here on Thumpertalk. I personally use a cheap 15w-50 name-brand non-synthetic non-motorcycle-specific oil and change it every other ride. It may not be as good as a motorcycle-specific synthetic, but I haven't had any problems.

  • skthom2320

Posted July 31, 2008 - 02:50 PM

#4

I'm fairly new to the sport so any advice would be great!


I'm sorry but I have to rebut this post. Especially since you are new to the sport. A lot of the stuff you read here on TT you have to take with a grain of salt! Don't worry, your tranny isn't going to fail. And your bike won't blow up if you don't use a stainless filter. And it will run fine for you on stock jetting.

But as you get better and better, and more involved, you may start to notice that your bike doesn't run perfect in certain weather. Or is hard to start at certain times (like when it is REALLY cold). Or it pops, or "gurgles" at certain throttle settings. This is all normal and most of the time it is just minor adjustments to the fuel screw and/or pilot jet.

Anyway, as for the filter, I'm just not a fan of the stainless filters. I don't believe they are a MUST have item like everyone would like you to think. I use paper ones in my CRF's now but when I had the 426 I just cleaned the OEM mesh one. I had the bike for ever 3 years, rode and raced it hard, and sold it to a guy who was still racing it when I last saw him (and hadn't done so much as a top end).

It was a seriously solid bike. A bit heavy perhaps. But very good and reliable.

As for the jetting, the JD jets are very popular here on TT but the '01 426 CAN RUN JUST FINE WITH THE STOCK NEEDLE! Maybe just a clip position here or there. And when it is very hot or humid, the '01 bike will definitely benefit from the JD triple taper needle BUT IT DOESN"T NEED IT FOR MOST RIDERS. It would run a little rough right in one spot about 1/8 throttle on the hottest days and no amount of clip/pilot would cure it.

But those days are very infrequent and I was able to have a lot of fun on my bike with the stock needle! But I did frequently adjust the fuel screw. Most of the time I used a little adjuster I made out of of nylon standoff with a drill bit epoxied into it. But then I bought a kouba fuel screw (still my favorite after all these years) and used that. But it's alittle harder to access on the CRF which is why I use the flex jet now.

Sometimes these discussion boards are just overkill!

The other mod that everyone will tell you to do is the "BK mod" which has you drill and tap into a little post on your carb. YOU DON'T HAVE TO DO THIS EITHER! The '01 bike runs just fine without it. LOL! Sheesh. :ride:

Visit the ThumperTalk Store for the lowest prices on motorcycle / ATV parts and accessories - Guaranteed
  • BASSic

Posted August 01, 2008 - 07:13 AM

#5

As for the jetting, the JD jets are very popular here on TT but the '01 426 CAN RUN JUST FINE WITH THE STOCK NEEDLE! Maybe just a clip position here or there. And when it is very hot or humid, the '01 bike will definitely benefit from the JD triple taper needle BUT IT DOESN"T NEED IT FOR MOST RIDERS.


I wasn't saying it's absolutely necessary. I didn't notice any drastic performance changes, but for the money it came with a good assortment of jets and the two JD needles which give you a lot of flexibility for any condition.

You do make an excellent point though: for someone new to the sport, jetting is something to not focus on right away, unless of course his jetting is way off and the bike isn't running right.

The other mod that everyone will tell you to do is the "BK mod" which has you drill and tap into a little post on your carb. YOU DON'T HAVE TO DO THIS EITHER! The '01 bike runs just fine without it. LOL! Sheesh. :ride:


Again, you're correct that it's not needed for most people, but if done it provides you with more options for fine tuning.

When I got my bike, I was obsessing over everything, but I started getting carried away. I realized if I did that too much I got distracted and ended up working on something or fixing something that didn't really need to be fixed when I could have been out riding.

  • jmckinney

Posted August 01, 2008 - 09:49 AM

#6

I was in your shoes about 5 years ago... Overall it's a great bike and you can always make it better and spend endless amounts of money to make it the bike perform and look the way you want it. Below is a list of Mods i have done:

1. Auto Decompression Cam - If your bike stalles on a hill or a of camber trail the decompression cam makes the bike start much eaiser. Some people say the decompression lever does not bother them, but for me it was one of the best mods.
2. Fly Wheel Weight - If you are planning on doing some trail riding then this is a must, prevents the bike from stalling.
3. 2002 Clutch Upgrade - The 2000 clutch is a little chunky and does not allow the clutch to be feathered when you are coming into a turn or climbing a hill. This is one of the best upgrades along with the cam.
4. JD Jetting Kit - As described above people fill diferantly about the kit. I personally feel this was a great way to dial your bike in and eliminate some of the intial bog from when you twist the throttle.
5. Gearing - Depending on what type of riding you do get the correct front and rear sprockets.

Overall it's been a great bike with majior problems.... Good Luck!!!

  • skthom2320

Posted August 02, 2008 - 08:34 AM

#7

When I got my bike, I was obsessing over everything, but I started getting carried away.


I did absolutely the same thing. ;)

That's why I wanted to point out that some of these things are not essential!:ride:

  • TeamTech

Posted August 03, 2008 - 09:39 PM

#8

Thanks a lot for all of the advice guys, it is greatly appreciated.





Related Content

 
x

Join Our Community!

Even if you don't want to post, registered members get access to tools that make finding & following the good stuff easier.

If you enjoyed reading about "" here in the ThumperTalk archive, you'll LOVE our community. Come join ThumperTalk today!

The views and opinions expressed on this page are strictly those of the author, and have not been reviewed or approved by ThumperTalk.