YZ426 frustration, Dirty carb??
Posted March 22, 2005 - 05:12 PM
Now the problem, I meet the seller get on the bike and use the standard starting technique recommended by yamaha/most posts I had read here to my suprise it started on the first kick. I pay the guy get the bike home and warm it up run it up and down the alley behind my house it ran great. The next morning i was going to go riding I try to start it and nothing so after working up a sweat i decide the plug is probably fouled. I go get another plug pull the old one (it was sooted up) I'd been kicking/pulling the plug for almost a day with nothing more than a 2 second idle before cutting off. A good friend of mine shows up and kicks it once it fires and runs!! he hits the engine stop button and says"so whats your problem" well he soon learned as we have not been able to get it running again even after replacing the plug. The only thing i have changed is the idle setting after reading posts about the idle affecting starting but I've tried starting at many idle positions and i would think that it would still start as long as the idle is somewhere close. I've checked the spark and its there and its getting fuel.
I love the bike its the cleanest 2000 I think I've ever seen but I'd rather be getting it dirty instead of looking at it sitting on a stand......any suggestions???
Posted March 22, 2005 - 05:19 PM
Check your fuel screw position, it should be at about 1 1/2 turns out from lightly seated.
Try clearing it out, hold the throttle wide open, with the compersion reliese in, and kick it about 20 times. Then go back to the normal satrting procedure.
Kick it all the way through the stroke , speed is not the key, but a good strong kick all the way through is, Get it to top dead center, and kick it good.
If your gettin spark, gettin fuel, gettin air, she should fire.
Posted March 22, 2005 - 05:29 PM
Posted March 22, 2005 - 05:54 PM
Posted March 22, 2005 - 07:07 PM
1.Pull out the hotstart.
2.Pull and hold the decomp in.
3.Hold killswitch in.
4.No throttle, kick through 20 or so times.
5.Release decomp and killswitch, push hotstart back in.
6.Pull choke out.
7.Kick through to TDC.
8.Pull decomp and kick one inch past TDC.
9.Release decomp and kick all the way through.
If it doesn't fire within four kicks (ie steps 7-9), push the choke back in and repeat 7-9 without choke.
Posted March 22, 2005 - 07:28 PM
Posted March 22, 2005 - 08:21 PM
Checking the clearances is a simple job.
Pull off the tank, the cam cover and the flywheel cover. Turn the flywheel with a socket until you see the 'I' through the viewing hole. Stick feeler guages under the cam lobes and measure the gaps. Too easy.
They will tighten. From memory, exhaust should be 0.25-0.3mm and intake 0.15-0.20.
Posted March 22, 2005 - 08:57 PM
When being careful not to touch the throttle while kicking it, did you give any throttle blips at all before kicks? Sounds to me it does not get fuel and therefore won't run. When I had my 426 I was a master to get it running and often had to help out others.
Engine hot, give it air (hotstart) and no gas. You may need to ventilate it as yzfmxer described.
Engine cold, tip over the bike till you see fuel dripping from carb hoses, then give 2-3 blips, choke on, hand off the throttle, max. 5 good kicks, if not starting then choke off and hotstart on, kick again several times before you go back to choke and perhaps one more blip. Remember, when you pull the decomp lever at TDC, all you need to get the piston past it is one millimeter to change the piston direction. Let off the decomp and bring the kickstart back up and give a solid kick-thru.
You will find the way to fire it up. When you get familiar with it and after some good riding it suddenly won't start and gives only pops, time to throw in a new spark plug again. Good luck.
Posted March 22, 2005 - 09:07 PM
Your friend just accidentally gave it a blip precisely at right time when kicking.
Believe me, you're not giving it gas it needs to fire up!
Posted March 22, 2005 - 09:33 PM
Posted March 23, 2005 - 05:03 PM
I then proceeded to kick till my face was blue changed the plug and tried again thinking I was going to kill myself I sat down and took a break reading the manual preparing for a valve check/shim. Getting my wits about me I pulled the decomp lever pumped through like 20 times, boom a blue flame shoots out of the pipe. I find TDC kick it like I mean it and viola instant start I had forgotten how bad ass it sounds I took some high speed spins across the parking lot(the first I had been able to do) and it was all worth it. THIS THING IS A HOSS it pulls like crazy and I can tell once we get to know each other we'll get along just great. To anyone with a "new to them" 426 be patient and learn what the bike wants with the cleaned out carb the starting procedure yzfmxr and bucky suggested IS SPOT ON . Having just come of xr's and older 2-strokes I feel like I'm going to do a backflip everytime I blip the throttle and I'm smiling from ear to ear
Posted March 23, 2005 - 07:53 PM
Posted March 23, 2005 - 08:00 PM
I would use the P38 and the BK mod.
DO a serch for the BK mod, you will find everything you need to know about it and how to do it.
Posted March 23, 2005 - 08:03 PM
Posted March 23, 2005 - 08:04 PM
Posted March 24, 2005 - 06:57 PM
Posted March 24, 2005 - 07:30 PM
Just drain the float bowl after each ride and I doubt you'll have any problems in the future. They're bullet proof!
Posted March 25, 2005 - 05:01 AM
Great to hear you got it going quickly, plusdome. Sounds like you had a good day. I went out too. Rode trails for about 4 hours, going fairly hard...well, fast enough for me. All sorts of terrain and it only used 2/3 of a tank. Not bad I reckon - we probably covered 70kms.
Had two big get offs. Went over the bars going slowly down a ledge and the bloody big thing landed on top of me - pinned me face down in the ground! Luckily, had a pack on with a two litre water bottle in it which saved my back. Went over the bars again in third or fourth gear. Too quickly over rocks, wrong line, ouch. Mild concussion I think. All good though!!
Get into it. Keep ontop of the oil changes and hopefully she'll serve you well.
Posted March 25, 2005 - 07:10 AM
I will add a few items to the list
The Dril Learn it, love it, Sleep with it and most of all kill anyone who twists that GRIP
The GBmod GBmod Explained Thanks Garrett
2001 Clutch Fix 2001 Clutch Fix for 2000 426
And last but not least the EPJ needle fromt he 2001 426 5JG-14916-JP-00 .NEEDLE (#EJP) STD(5JG5) this will help lean the mid out and give you a bigger hit in mid when the bike hits the cam
First Hare scramble tips by dhend8
YZ450F 03 Sparks driving me crazy by SirAttard
yz250x vs 450 4t comparisons (preferably desert riding) needed by JakeNorthrupYZ450F