How to fix difficult starting on YZ426?


35 replies to this topic
  • wc426mx

Posted January 27, 2005 - 08:30 AM

#21

Here's what I've done to my '01 426F. I did a modified version of the BK Mod, only adjusted the screw about one turn and the Blue Wire mod. Those helped quite a bit for sure. Then, I just recently bought the 450 cam and had the valves adjusted at the same time. WOW, I wound up with a new bike it seemed once I tried to start it. I've ridden the bike on just two occasions since the work and I'm totally amazed at how different the bike seems. Take my word for it, get the 450 cam and "screw the drill".

I was skeptical like the next guy, but now I'm a believer. For example, my brother came over to spectate while I was doing a shock service. Upon completion I had to show him how easy it was to start the bike now. I was standing beside the bike, on the right side, and started it with one kick with my right leg. You'd never even try this with a stock cam! I'm 6' 1" tall and weigh 153 pounds, not exactly a lot of mass to help out here.

Plus, for trail riding with my 13 year old son who stops all the time, bump starting is unreal. Second gear, barely rolling, just dump the clutch. Voom, you're off.

Do the cam and report back!

Bob :cry:


Thanks again everyone for all of your help on this subject. The 450 cam sounds better and better all the time. :cry: I do have a few questions about it though. Hopefully someone can help me out. First, does the 450 cam cause any premature wear (more than an auto-decomp Hotcam) inside the 426 motor? Is there any need for the other 450 cam? Where is the best place to get the 450 cam & how much $? How difficult is it to install? Anything else I need with the cam? Thanks.

  • John_Lorenz

Posted January 27, 2005 - 08:44 AM

#22

My 2000 starts 1st to 2nd kick hot or cold. Any bike or any thumper if Crashed is going to be a beast to restart.

First Do the GBmod
GBmod Explained

Second
Properly Jet your bike for your riding area.

Last Know the Drill, Live the Drill Love the Drill
The Drill

  • MichiganMXer

Posted January 27, 2005 - 10:09 AM

#23

My 01 is pretty picky about the gas I put in it. I've put a fresh tank of 93 in it before and it ran like shit for like over a month. It was "fresh" gas. Fouled plugs, bogging down, popping on decel, all over shit gas. I messed w/ the carb and everything; nothing worked until I just drained that trash and put in some 100 proof and BAM! Been runnin great since.

  • starttman

Posted January 27, 2005 - 10:47 AM

#24

i'm spoiled... i got the 03 450... but i had a 2000 426... i had the drill nailed...to this day i can start any 426 you put in front of me.


I love going to the track and see these guys who just picked up a used 426 or even a 250 and can't start it....I jump on and get it right away...pisses them off...

  • blue_beast_wins

Posted January 27, 2005 - 12:08 PM

#25

get the 450 cam and "screw the drill".




:cry: :cry: :cry: :devil: shiit yeah !! :cry: That drill thing is worse than foreplay ! :cry:

  • John_Lorenz

Posted January 27, 2005 - 12:18 PM

#26

i'm spoiled... i got the 03 450... but i had a 2000 426... i had the drill nailed...to this day i can start any 426 you put in front of me.


I love going to the track and see these guys who just picked up a used 426 or even a 250 and can't start it....I jump on and get it right away...pisses them off...


:cry:

you got that right

  • slappie

Posted January 27, 2005 - 01:34 PM

#27

Even the 450s start easier if you bring it up to TDC first before kicking it over.

Mine will start 1st or 2nd kick always (hot, warm, cold, lukewarm, etc) if I do that. If not, then when cold, who knows when it will start.

  • OldenPhatt

Posted January 27, 2005 - 03:59 PM

#28

I've got an 02 426 and I had the drill down, but as others have said, it was still a bear to start when stalled. I now have the 450 cam and it really rocks! It's as easy to start as my two-stroke, I really think it's worth the effort and cost. I suppose it's also easier to start when stalled, but since I put in the Rekluse clutch it never stalls!

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

Posted January 27, 2005 - 06:13 PM

#29

Thanks again everyone for all of your help on this subject. The 450 cam sounds better and better all the time. :cry: I do have a few questions about it though. Hopefully someone can help me out. First, does the 450 cam cause any premature wear (more than an auto-decomp Hotcam) inside the 426 motor? Is there any need for the other 450 cam? Where is the best place to get the 450 cam & how much $? How difficult is it to install? Anything else I need with the cam? Thanks.



Back to addressing WC's questions....

WC,

There have been speculation that the 450 Cam "Might" cause premature wear or failure. Unfortuneately, its speculation and there hasnt been any failures to report of to this day.

The Hot Cams 426 Auto Decompression will give you exactly that, and thats it! If you want to see better performance, you will also need to get the Hot Cams Intake cam also. So, now you looking to spend about $150 Bucks a Cam to get performance and Auto Decompression.

There is no need for the other (Intake) 450 Cam. With the exhaust cam you will not only get Auto Decompression, but you will also see a preformance gain throughout the powerband. I know when I did mine, it actually smoothed the entire powerband out in my opinion.

As far as price, you can search through the PINNED 450 DCM Post at the top of the forums, and I think around page 87 you will find some mentioned places. I was able to get mine from out local shop in which we get eomployee discounts for $95 bucks + Tax. They retailed for $158 at the shop, so getting the employee discount was nice. I believe I saw posts that the place you can call they will get around $106. The was also some posting in the forums that had an extra one for $100 bucks, he also has it listed on ebay.

Installing, nothing special, Remove tank, top engine mounts, and valve cover, and chain tensioner. Unbolt cam, check what # Shims you have under the buckets, put the new one in, line up the lobes on the right side so that they are symetrical, bolt the cam in place, and take feeler guage measurements. 9 out of 10 times you will have to run down to the local shop and get new shims. I went from 181 & 186 to 200 on both. Granted, this is the abriviated way just to give you an idea of what your looking at, but Download the document on how to do it, read it one time over before you start, and just follow the directions...

You wont be disappointed!! JUST DO IT!!

  • wc426mx

Posted January 28, 2005 - 01:50 PM

#30

I'll have to check out that thread again. How long has the 450 cam mod shown itself so far without problems?

  • assgasorgrass

Posted January 28, 2005 - 02:33 PM

#31

I just got the 450 cam at generationmx.com - I think it was about $96 plus shipping.

  • wc426mx

Posted January 31, 2005 - 12:00 AM

#32

Will installing the 450 cam affect my jetting that much?

  • Fastest1

Posted January 31, 2005 - 10:55 AM

#33

Some of us had installed the cam in 03, so 2 years with no problems. Some with high mileage too!

  • FLYIN200

Posted January 31, 2005 - 03:36 PM

#34

When you install the 450 cam. Can you iliminate the decompression lever.

  • wc426mx

Posted February 05, 2005 - 02:01 PM

#35

When you install the 450 cam. Can you iliminate the decompression lever.

Yes. If you install the 450 cam, you can get rid of the manual decompression lever/cable. If you do this, you will need a special decompression plug. The TT store seems to have the best deal on these plugs. http://shop.thumpert...p/qmr-03dpb.htm

  • ockevin

Posted February 05, 2005 - 09:28 PM

#36

Dominator,

Great video and how to start a 4 stroke.





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