new to the 426 as well as dirt biking!

54 replies to this topic
  • MuDPoUNdeR

Posted February 08, 2009 - 10:32 PM


My next mod will definitely be the BK mod, i will be doing that this week. I love this bike and it has excellent power. Only downside to the bike is the weight, it is pretty heavy.

That mod will be worth your while! It's a great mod!

  • rufusz

Posted February 09, 2009 - 12:27 AM


I was told to do the auto-decompression cam mod but I didn't want to spend the 200 on the new cam. So I bypassed that mod. And I do not regret. I have no problem starting my bike, hot or cold. And most of the time I am started a lot faster than my friends with newer bikes, (GRAYRACER513 - Glad to hear you are the master starter and bump starter, but it seams that more people tend to agree with this side, at least ones that gave the decompression lever a chance.)

I've had my 426 for 6 months before I installed a HotCams exhaust cam with auto-decomp and never regretted my decision. People who swear by the manual decomp, are only those who didn't do that mod. Show me someone who removed his auto-decomp exhaust cam and has gone back to the manual decomp! I still have my old camshaft, I'll send it to you with the manual decomp lever, cables and put it in your bike :)

  • Florida_426

Posted February 09, 2009 - 07:04 AM


I own a 2002 426, had it since it was new from the dealer in May 2002. I did the DCF cam modification (used the Yamaha 450 exhaust cam) while I did the piston rings in July 2003 and have loved my bike even more since. I did put in a Hinson complete clutch package in 2005 as the plates were starting to wear thin and the ears of the clutch basket were getting notched.

One modification I did I don't hear much about is the Boyessen water pump impeller and cover. I had a boil over issue at a race in Dec 2002 so I went to the Boyessen impeller and water pump cover. No problems since doing this.

I keep the oil and oil filter fresh (I have a Dr.D hour meter) at regular intervals and always clean and re-oil the air filter after each ride or race. Keep the bearings in all the locations greased (I did a complete Pivot Works replacement in 2006 as a precaution.) I truly enjoy the bike and would recommend the DCM as the forst and a must do modification.


  • grayracer513

Posted February 09, 2009 - 07:28 AM


Glad to hear you are the master starter and bump starter, but it seams that more people tend to agree with this side, at least ones that gave the decompression lever a chance.

I gave manual compression releases "a chance" from 1966 to 2004. I've ridden 20-30 or more different kinds of bikes equipped with them, some of which you've never heard of, most likely. I'm familiar and completely comfortable with them. I know how to do everything with them that can be done, and almost didn't buy my old '03 YZ450 because it didn't have one. It took me about 2 weeks to decide that I was never going to convert it to manual decompression (easily done, BTW), and I haven't missed having it since.

Starting a YZ450 with AD is no different than starting a 426 without it; there's a right way, and a lot of wrong ways. I can start mine faster/easier than a lot of people can start their AD 450's, so what does that say? You can always do it wrong. I have at least one riding buddy with a 426 who hasn't figured it out in 4 years of owning the same bike, and has all kinds of trouble starting it. Once he hopelessly floods it, I can usually get it going in 4 kicks or less, and I can walk up to the bike at any time and get it going in no more than two. Pisses him off.

Anyone who has given auto decompression "a chance", and made a half-serious effort to get it right will never agree with the ridiculous claim that you can start a manual decompression engine faster. It's BS, cold and simple as that. You may be comfortable with manual decompression, and you may have totally mastered it to the point where it's second nature, and requires no conscious thought at all. That's fine. I'm proud of you. It's a skill every complete motorcyclist should have. But it doesn't mean that auto decompression isn't better. It is, and that's just the way things are.

  • ryno060

Posted February 09, 2009 - 07:35 AM


I am sure if someone was to upgrade to the autodecrompression cam that they would like it and not go back, but if you don't you get used to it and its not that big of a deal

But if you would like to send me your old set-up i would love to have an extra for a backup, lol:smirk:

  • ryno060

Posted February 09, 2009 - 08:18 AM


I will not argue that AD is better. I am sure that it is. And I know that for many it can be very easy to mess up a starting a bike (any bike for that matter) I am just saying that i dont mind the MD and I dont regret not doing the switch. But My next bike will be newer and will have the AD so I will understand more at that time, lol.

Question - has anyone done both the BK mod and the 1/4 turn throttle mod. I just wanted to know if the BK was fine by itself or if the throttle mod is a good additive to. I thought both of them might be a little to much for the bottom end.

  • yamihoo2

Posted February 10, 2009 - 05:44 AM


I'm not going to argue whats better either, obviously its just a matter of preference and spending the money and doing the work to save time and potentially hassle down the road.

I've rode many bikes with and without it, and its just not a big deal to me.

Now I have heard of some issues with AD cams sticking on other engines, one of my past atv's did this, haven't heard of any problems with this model of course no.

If you add up the positives and negatives, sure AD may win, but to tell someone who hasn't even rode their bike yet, or barely tried it, to just go ahead and do the mod because you prefer it is a little pretentious I think. Sounds like some people have done the mod and aren't qualified and end up causing more trouble then good (wrong valve clearance, wrong timing etc.)

Just my .02:cheers:

  • Digger01

Posted February 10, 2009 - 08:19 AM


Im ready to do my decomp mod...Im the one who has to hike out to the bike if someone cant start it, usually my cousin. I usually turn my idle up a little for a someone but people stall all the time.

We all rode when we were young, now Im in Jersey and they are stuck on Long Island..(Islander by birth Jersean by grace of God) they come to me if they want to ride.
Just a note Everyone of them was amazed with the 426 power compared to yesterdays bikes, they all ride street now.

  • buzzgrizz

Posted February 10, 2009 - 04:00 PM


My son has had a 2000 426 for about 3 years now and it has been a very good bike. Enjoy yours.

  • grayracer513

Posted February 10, 2009 - 09:43 PM


... to tell someone who hasn't even rode their bike yet, or barely tried it, to just go ahead and do the mod because you prefer it is a little pretentious I think.

No more so than telling someone it's no big deal because that's your preference.

As far as causing problems by working on your bike, one needs to understand the machine, and know his limits, as with anything else. Some people are not qualified to change tires, oil, or air filters. But most people who have C/B level skills and are capable of adjusting valves are capable of installing an AD cam, particularly if using an aftermarket camshaft made for a 426.

Visit the ThumperTalk Store for the lowest prices on motorcycle / ATV parts and accessories - Guaranteed
  • yamaha2000

Posted February 27, 2009 - 06:44 AM


I wouldnt go quite as far to say hate. when you are not farmiliar with what start technique your bike likes, then yes it can be a pain. Most people say its the best mod to do. I disagree, simply because it is an excellent theft preventer because nobody can start a manual decomp bike, who hasnt owned one before. And to me it seems like a waste of money because I have had kickstart contests with my friends who have newer yz 450s, and have won over 90% of the time. My bike fires first kick, hot or cold. I would prefer to use that money for a skidplate or tri-clamps. Just my .02

well about the auto decompression thing. I just bought an 2000 yzf 426, and it has the auto decompression thing on it. which im only 15 and i only weigh 140. but i know nothing is wrong with the bike cause i can pull start it and it will crank right up. So what are some methods you use to kick start it???

  • yamaha2000

Posted February 27, 2009 - 07:14 AM


i have a yzf 426, 2000. It has one of the decompression levers on it, but even using it i still cant crank it. It may be because im only 140lbs. but i know it works cuz i can pull start it and it cranks right up. Could you tell me some methods you guys use to kick start it?

  • grayracer513

Posted February 27, 2009 - 07:21 AM


The most important thing about getting a 426 to start well, regardless of whether it has AD or not, is getting the carb tuned right. Get an extended pilot screw if you don't have one, and learn to keep the idle mixture set properly.

With auto decomp, the best method is to push the engine up against the compression stroke, reset the lever back to the top and give a full length smooth kick from there. Don't stomp or stab at the crank. Take the slack out with your foot, then drive it through. You can also just kick it repeatedly from wherever the engine happens to be stopped, but it does work a little better as above.

With manual decompression, follow these methods:



Cold, pull the choke and kick it once or twice. If it doesn't respond, try giving it one twist on the throttle, then kick again with the throttle closed. Occasionally, you find one that likes a very small opening of the throttle, barely off idle, but you have to be able to hold it steady as you kick without twisting it the way two stroke riders like to do.

Warm, it should fire up with the throttle closed, no choke.

  • travisn

Posted March 02, 2009 - 06:51 AM

#34 getting the carb tuned right...

How does one go about ensuring the carb is tuned right? I have never had a carb apart before...

  • grayracer513

Posted March 02, 2009 - 07:17 AM


Mostly, it's the idle circuit that's important to good starting:


  • yamihoo2

Posted March 03, 2009 - 05:56 AM


umm yeah, if you ever intend on riding in the woods, on a actual trail... you should probably learn how to kick start your bike.

My biggest concern with the dc lever is breaking it out in the woods far from civilization where I ride...that would then become interesting. I do have good bark busters for protection anyway. But I guess I could just refamiliarize with the old days when they had the lever on the valve cover without the cable/hand lever.

Enjoy the bike! Most of us seem to, either way.

  • Clb33fyxj

Posted March 06, 2009 - 09:11 AM


funny, last time i went for a ride i took a big digger and broke the decomp lever off my magura clutch cover. you just have to reach down on the right side of the engine and actuate the decomp with your hand. not a big deal but im gonna do the hotcams cam in the spring.

  • yamaha_mx_13

Posted March 07, 2009 - 02:01 PM


The first thing you should is change the exhaust cam to auto decompression or you will hate this bike !!

You dont have to spend a lot of money on a new cam u dont need, the people that do, dont know how to start a 426.

  • grayracer513

Posted March 07, 2009 - 02:10 PM


You dont have to spend a lot of money on a new cam u dont need, the people that do, dont know how to start a 426.

The people who say stuff like this don't own a 426 with Auto Decompression.

  • yamihoo2

Posted March 08, 2009 - 10:25 AM


Complacency and laziness...its an epidemic

Related Content


2016 YZ450 by CaptainKnobby

Dirt Bike   Dirt Bike Technical Forums   Suspension
  • Hot  59 replies

Is the 2016 GYTR Yamaha YZ450F too fast? by Fryboy

Dirt Bike   Special Interest Forums   Pro Racing
  • * - - - -
  • Hot  241 replies

Need help by Goforaride

Dirt Bike   Dirt Bike Technical Forums   Suspension
  • Hot  68 replies

yz400f throttle bog by yz400fmaniac

Dirt Bike   Make / Model Specific   Yamaha   YZ 400/426/450
  • * * * * *
  • Hot  28 replies

Michigan Motocross Tires by 288yz450

Dirt Bike   Dirt Bike Regional Discussion   North
  • 1 reply

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.