2001 YZ426F- New owner- same problems


16 replies to this topic
  • mightymouse291

Posted August 02, 2005 - 06:33 PM

#1

Let me start by asking your forgiveness for my ignorance...

I have read many of the posts here for the starting problems with the 426. I would like some more information regarding two things:
1. The (or any) stock 426 starting routines that actually work

2. The 450 cam modification
It does create an "auto" decompression? How long for the novice thumper wrench?

3. Anyone in Texas that has done this?

I laid down my manly pride to ask you all. I have ridden two-strokes for 10 years, and dove into the thumper world. I just need a little help since I kicked forever today, only to foul my one and only plug.

Thanks for all the help that you guys are putting out there for us newbies....

  • grayracer513

Posted August 02, 2005 - 07:10 PM

#2

Assuming you have a service manual, and are an otherwise reasonably competent mechanic who has never done a valve adjustment on a YZF, you can expect to spend two to three hours doing the auto decomp cam swap. You do not NEED to remove the right radiator, altough it may be necessary to do so in order to remove the manual decomp shaft, if you decide to. You can leave it in, but you have to keep the return spring on it. You will probably have to reset the exhaust valve clearances, as well.

Before you remove the exhaust cam, bring the engine into the timing position and ziptie the chain to the intake sprocket, so the intake cam won't have to be re-timed. Remember that the timing marks on the 450 cam are for the 450 head, and won't line up like your stockers. With one mark on the exhaust cam at 9:00 and the other at 12:00, count 14 PINS between the two 12:00 marks for you timing.

And yes, it does provide totally automatic decompression.

Hang onto This Picture

From this thread: http://www.thumperta...ght=decomp mode

On starting, the biggest single mistake made by two stroke riders is that they twist the throttle with every kick. You will absolutely never get your 426 to start this way. If it's running right, it will start most of the time with the throttle completely closed, at idle. If you can't break the habit, put your hand half way up on the throttle housing to keep you from turning the grip.

Cold: Choke on. One to three twists of the throttle to prime. bring it up to compression and take the pressure off the crank. Pull the compression release and move the crank down just an inch. Release the decomp lever, reset the kickstarter all the way up, and give it a full, smooth kick all the way through with the throttle closed. Repeat as necessary. Should start in two.

Hot: No choke! Open the hot start (at low altitude or in cool weather, this may turn out not to be needed, but most of the time it will be). Position the engine as above and kick it, again with no throttle. If you stalled it or dropped it, you'll want to clear the engine by kicking it through several times with an OPEN throttle (just hold it still, don't pump) and the compression release held down.

Once you get it, you'll be unstoppable, but the decomp mod is still the best approach to take.

3. Anyone in Texas that has done this?

The name "Satch" somehow springs to mind. :D :D

  • mightymouse291

Posted August 02, 2005 - 08:08 PM

#3

thanks for the reply

  • s3706

Posted August 03, 2005 - 06:09 AM

#4

hey mightmouse,

I have a 00 426 that I upgraded with the auto decom cam about eight months ago and it works great. Just follow that info that gray posted and you should be fine. I live about 25 miles northeast of dallas, so if you live within the dfw area and need help with your cam mod I would more than happy to turn a wrench with you. Then we can load up and go tear up some dirt. :D

  • mightymouse291

Posted August 03, 2005 - 01:28 PM

#5

I have relocated to the Austin area, but make rounds that way very often. I will give ya a shout if I'm up your way....

  • Satch0922

Posted August 03, 2005 - 02:27 PM

#6

GrayRacer....you da man!

The cam mod is the best mod you can do to the 426...bar none. If you need any help with it just send me a PM. I am in Frisco (North of Dallas).

I have since gone back to a 2-stroke but only because I am old and slow anyway and wanted to get back on a smoker while I still can. 2007 will see my return to the YZF if I am fortunate enough to still be riding then.

Until you get the cam mod done use the advice of GrayRacer . Also...check this out..

Starting tips for YZF owners

  • mightymouse291

Posted August 08, 2005 - 05:58 PM

#7

Thanks for all the help on my issue guys. A new plug, and the BEAST fires on one kick. You saved a mighty fine blue angle from the trade-in pile of the local shop....

...Can't wait to hear more from you guys

  • RJB

Posted August 08, 2005 - 06:39 PM

#8

Satch, I'm gonna PM you for some help on this if its ok. I've got to get this done on my bike sometime - just haven't gotten around to it. Perhaps when the temperature drops a bit if you're up for it?

Visit the ThumperTalk Store for the lowest prices on motorcycle / ATV parts and accessories - Guaranteed
  • ironbird456

Posted August 09, 2005 - 12:12 PM

#9

Hey Satch how often do you go to Muenster?

  • Satch0922

Posted August 09, 2005 - 03:41 PM

#10

Satch, I'm gonna PM you for some help on this if its ok. I've got to get this done on my bike sometime - just haven't gotten around to it. Perhaps when the temperature drops a bit if you're up for it?



No problem! I will be glad to help.

  • Satch0922

Posted August 09, 2005 - 03:42 PM

#11

Hey Satch how often do you go to Muenster?


I have only been to Muenster one time in the past year and a half. I am ride/race motocross. One day though I want a second bike that I can take to Muenster. That place will destroy a bike though! :D

  • Thrash1

Posted August 09, 2005 - 04:41 PM

#12

Is Muenster really that bad though, It can't be any sandier that Lake Murry's riding area.

I have a 426 as well and if you follow the starting procedures It will fire no problem. I did have a hard time the other day trying to start after a get off but it was 100+ and I was really tired and couldn't kick it over fast enough.

Any Weekend you guys want to meet in Muenster I'm game. A bunch of 426's beatin on Pingers sounds like fun.

Good Luck on the Mods

  • Satch0922

Posted August 10, 2005 - 03:07 PM

#13

Muenster is rocks, sand, salt water, etc etc that destroy a bike. Don't get me wrong...the riding is a blast...but you better be riding a bike that will never enter a beauty contest.... :D

  • mightymouse291

Posted August 10, 2005 - 07:49 PM

#14

I raced both of these tracks back in my "yankee" north texas days. Muenster is all the above with the unforgiving QUICKSAND in the creek crossings. It was always in the middle of summer, hot as hell, start delayed an hour or two...Ist race was on a '83 YZ100 for 50 miles (in '95)....But alwys fun and challenging terrain.

Lake murray was one of my favorites....unless it rained. The sand whoops were awesome, and I always enjoyed the sand there. The last time there I buried my 97 rm125 up to the rear fender in a mud hole in the middle of the woods..(3)4-wheelers later i was out and lived to ride another day.

Both are fun and great places to ride. Take advantage of the riding areas like that, there are not too many open lands riding ares down here in Central TX

  • 913YZ426MXer

Posted August 11, 2005 - 07:14 AM

#15

hey mightmouse,

I have a 00 426 that I upgraded with the auto decom cam about eight months ago and it works great. Just follow that info that gray posted and you should be fine. I live about 25 miles northeast of dallas, so if you live within the dfw area and need help with your cam mod I would more than happy to turn a wrench with you. Then we can load up and go tear up some dirt. :D


s3706,

What did the cam cost you? :D More importantly, how long did it take you to install? Please advise. :D

  • mightymouse291

Posted August 11, 2005 - 07:11 PM

#16

I think that the cam is around $93...I read it in a thread around forum. Grayracer thought that the install might take 3-4 hours for someone with some wrenching skills.

  • mightymouse291

Posted August 11, 2005 - 07:15 PM

#17

heys there guys.. I took out the 01 YZ426 for my first time to the mx track. I have to say that I found out real quick that a thumper has to be ridden a little differently than the old 2 strokes. I killed it 2 times on the first lap, but I overcame it and proceeded to put in some goods laps....The hotcam is still a priority of mine





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