426 ran in awesome


14 replies to this topic
  • nathanyzf426

Posted June 22, 2008 - 11:40 PM

#1

gidday as alot of you know i was getting my motor rebuilt due to the conrod snapping i got it back on saturday i was up till about 11:00pm putting it back together. i ran the bike in on sunday(yesterday) it went awesome today i rode it pretty hard i must say it has some :thumbsup: grunt now my only 2 troubles are as is 1/ when i go to kick it some times it will fire right up but some other times it takes quite a bit to fire could this just be due to my lack of muscle in the legs or could this be due to valve clearances for you boys who dont know what im about i have just upgraded to a thumper rode 2 strokes my whole life so its a whole new ball game. now as for #2 when she is about to take off it stalls if i dont rev it out i can hear when its about to do it and i pull the clutch in to prevent the stall but it does nothing and stalls any way this dont seem right to me i do know they say it has a grabby clutch in th 2000 yz426f and to do the 01 mod but is this neccessary or could there be something not quite right i was planning on checking my valve clearances just to be on the safe side but would like to know a few more inputs thanks nathan..... gray cheers for the link to the service book turns out i got to my mates who i got it off and he had the bloody book so i now have one for it thanks any way mate.................

  • DeeCee

Posted June 23, 2008 - 12:05 AM

#2

Sounds to me you need to sort your carburettor settings out.

First give the carb a good clean out (blow out all the passages and jets) and see if that makes any improvement.

Check the sticky's for carburettor settings for the 426.

Once it is set up right it should start easily and with pull away with no bog.

You may find the clutch is not an issue once you sort the jetting out.

  • nathanyzf426

Posted June 23, 2008 - 12:40 AM

#3

i will check out the jettings as for the carb being cleaned i totally pulled the carb down and cleaned out everything with carby cleaner spray yes alot of black crap poured out but that was before i put the bike back together so i cant see it being dirty or blocked as i flushed my tank before fuel went in then when fuel did go in i left the fuel line going to the carb off let the crap (if any) settle for ten then let some fuel run straight outr onto the ground then hooked it up so mate imo i dont think its blocked but yes will look into the right jettings cheers any one else????????

  • sirthumpalot

Posted June 23, 2008 - 02:54 AM

#4

Are the starting problems when it's hot or cold? If it's cold, use the choke. If it's hot, use the hot start. Do NOT twist the throttle while you kick like is common on a 2-stroke. See if that helps.

  • YAMAHA 426 YZ RIDA

Posted June 23, 2008 - 04:13 PM

#5

Hi, I Just Brought A 01 Yamaha 426 Yz. At First I Couldnt Get It Started At All Without A Friend Holding The Bike Steady So I Could Give It A Really Good Kicking. Once I Finally Figured Out How To Start It On My Own I Took It On The Trail And Ended Up Dropping It. It Was A Very Light Drop And It Only Layed Down For About 30 Seconds Or So. When I Picked It Up, I Couldnt Get The Thing Started Back Up. Can Someone Tell Me Some Of The Things I Might Do In Order To Get It Started And Also Let Me Know Why It Was So Hard To Start Prior To Me Droping It? I Would Really Appreciate It; Its Killing Me That I Cant Ride It Right Now; Its A Sweet Bike When Its Running. #2 Also When I Get It Running, If I Dont Keep Twisting The Throttle, It Will Shut Down. Can Somebody Tell Me What I Need To Do To Fix This Problem?

  • sirthumpalot

Posted June 23, 2008 - 04:49 PM

#6

(1) Raise the idle speed
(2) Check the valve clearance and timing
(3) Adjust the fuel screw
(4) Make sure the carb is clean and the filter is clean
(5) If the previous owner changed the jetting, the put it back to stock as a starting point

  • dacon1

Posted June 23, 2008 - 08:07 PM

#7

426 Rider: First, Check this out-

How to Start a YZ426 (Video with Doug Dubach- Special Thanks to Yamaha Motors, and all the Good People at Dubach Racing Development)
(Requires QuickTime, or a player that will handle QT videos)
Part 1: (Cold Start) http://www.yamaha-mo....roke_vid_a.mpg

Part 2: (Hot Start) http://www.yamaha-mo....roke_vid_b.mpg



Secondly, even after watching that, and knowing how its done, when you first get use to this bike, its going to take you FOREVER to get it started. I have several buddies with them, and the first 1-2 months they had them, they struggles to get them started. When they got use to it, it became nothing.

My advice, get your crotch as far forward in the seat as possible, get the kickstart in the "catch" of your shoe / boot (where the heal is raised on the shoe), and jump on it damn near.

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  • matt4x4

Posted June 24, 2008 - 07:00 AM

#8

Proper starting procedure for the pre auto decompression models is:
(and it may be as simple as this for you if your idle is already adjusted right)

1. Push kick starter until it hits TDC
2. hold decom lever and push kickstarter just a little to make piston get to beginning of downstroke (just past TDC).
3. Let go of decompression lever, move your right hand onto the gastank, bring kicker back up and one good powerfull kick right through.

If it sat for a week or more, before the big kick, twist the throttle a couple of times to add a little gas into the intake, but move your hand back to the tank.

It should fire right away - below 70 degrees - also use the choke.

If the bike was dropped or stalled on the trail and you want to start it immediately - pull out the hotstart plug on the carb (red) and use above procedure then push knob back in before leaving.

  • grayracer513

Posted June 24, 2008 - 09:19 AM

#9

Proper starting procedure for the pre auto decompression models is:

(video) http://www.yamaha-mo...troke_vid_a.mpg

http://www.yamaha-mo...troke_vid_b.mpg

  • YAMAHA 426 YZ RIDA

Posted June 24, 2008 - 07:06 PM

#10

hello all. yesterday i was on here and i had a few problems with my bike. its a 2001 yamaha yz 426. it has always been difficult to start up. I brought it used and the guy told me to do research and see just how many people were having trouble starting it. But to make a long story short. I dropped the bike and now it wont start at all. I cleaned the carbs,changed the gas,changed the spark plug and still nothing. Anyone have any advice?

  • dacon1

Posted June 24, 2008 - 07:41 PM

#11

YAMAH 426 YZ RIDA: Listen, and read. 4 guys told you what to do.

First: Watch this video: http://www.yamaha-mo...troke_vid_a.mpg


I've seen guys who have ridden their hole lives, fail to kick start a YZ426 in 10 minutes, I own the bike and its either 1st kick, or 25th. But i'm getting better.


Watch that video, and learn it. If your a smaller / shoter guy (100-180lbs, 5"0 - 5"10 ) get as FAR FORWARD on the seat as you can, put your foot FAR OUT on the kick start, and get it RIGHT in the groove in your shoes.


If you STILL find it hard. Go get the HOTCAMS EXHAUST CAM (I think thats the one) and it makes the bike MUCH easier to start. No decompression lever, just kicking.

  • nathanyzf426

Posted June 25, 2008 - 12:14 AM

#12

hello all. yesterday i was on here and i had a few problems with my bike. its a 2001 yamaha yz 426. it has always been difficult to start up. I brought it used and the guy told me to do research and see just how many people were having trouble starting it. But to make a long story short. I dropped the bike and now it wont start at all. I cleaned the carbs,changed the gas,changed the spark plug and still nothing. Anyone have any advice?



maybe check out the wiring you may have broke a wire im not too sure but just an opinion and also have a read through the other threads plenty on here for you to look at you just have too take the time to read through them which is also good to get a clearer look at what you can do to keep your bike in good shape plus if that dont work you are better off posting in the main threads you might get a better result then in here.........

  • DeeCee

Posted June 25, 2008 - 02:22 AM

#13

Take a look at the wires on the ignition coil.

The small wire close to the carburettor can be easily dislodged at times.

  • YAMAHA 426 YZ RIDA

Posted June 25, 2008 - 04:19 PM

#14

ok i checked everything and i realized i wasnt getting a spark. when i took out the spark plug and put it 1/8 inches away i couldnt see a thing. Then i decided to actually touch the spark plug while i cranked it and i barely got shocked at all. I am wondering if all my problems are stemming from a bad starter coil. it seems to give off too little energy considering that i cant see a spark. first the spark was n orange color and know i dont even get that. I got a new plug,new gas and cleaned the carb. already. somebody please help

  • kevin nichols

Posted July 15, 2008 - 09:33 AM

#15

Proper valve adjustment on the 426 can make a huge difference. I had starting problems and found my intake valves to be off. I changed out the shims for the proper clearance and it made one hell of a difference. It now starts every 1st or 2nd kick.





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