Pls help new YZ426 1st 4 stroke many problems


30 replies to this topic
  • skthom2320

Posted April 04, 2005 - 05:21 PM

#21

If you had one on your bike you wouldnt be saying that. No way in the world is the bike easier to start without the mod!. :naughty:


I've had my '01 YZF since new and I've never put the decompression cam in. I just don't need it since it always starts on the 1st or 2nd kick.

I do have a cam sitting in my garage. I just haven't got around to it since it really isn't that big of an issue for me.

  • shanet1975

Posted April 04, 2005 - 05:27 PM

#22

After reading a few other posts along with these, I have come to the conclusion that it may be the plug. I'll swing by the dealership tomorrow and try that. I'll need a special tool I believe as the spark plug is embedded miles down in the motor :naughty: Hopefully the local dealership has the tool. I tried getting a regular spark plu wrench in there and no good. Hopefully that will do the trick. If not I'll look into the mod.

  • simimi

Posted April 04, 2005 - 05:43 PM

#23

I have a 1998 YZ400F and no cam either. I got lucky and my bike must have been jetted spot on. Rarely do I use the hot start, but for first kick of the day the choke. I do the drill with one change. First start of the day I hold the decomp, twist the throttle once, kick it over 3-4 times and then start. Maybe that circulates some oil, maybe it just makes me feel good.

Also, I did the Boysen impeller and water pump housing, and also put on a KX250 radiator cap that holds a bit more presure than the stock one. Never had a boil over, fingers still crossed.

When I am lucky like this last weekend I killed the bike, was still coasting, and I did the drill while coasting. I have also figured out how to bump start it also.

Good luck, keep trying!

Mike

  • kizzle426

Posted April 04, 2005 - 05:58 PM

#24

I forgot to mention the plug. It more than likely is the problem. I changed mine. I didn't have to use a special tool for the plug. the plug wrenches are to wide to fit so I just used an extension and a normal socket. then i used a pipe spring puller to get a grip on it. Make sure you get the CR8E and you gap it between 7-8 mm. I put mine in and it starts perfect. i used 7.75 gapping on mine.

  • skthom2320

Posted April 04, 2005 - 08:56 PM

#25

After reading a few other posts along with these, I have come to the conclusion that it may be the plug. I'll swing by the dealership tomorrow and try that. I'll need a special tool I believe as the spark plug is embedded miles down in the motor :naughty: Hopefully the local dealership has the tool. I tried getting a regular spark plu wrench in there and no good. Hopefully that will do the trick. If not I'll look into the mod.


If it runs at all but just hard starting, a new plug may help but it is more likely just the jetting on the pilot circuit .

Does the bike pop on deceleration at all or do you have a "hanging idle?" If so, it's lean on the pilot and you need to adjust the fuel screw OUT about a half turn or so. Don't go more than about 2.5-2.75 turns total. If you need more than that go up a size in the pilot.


BTW - a wobbler and 3" extension with a spark plug socket will work just fine for the plug.

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  • sanpedro426

Posted April 04, 2005 - 08:57 PM

#26

Dont get why the dude wants or needs to drain the carb. I would think that would only allow the rubber in the seat/needle shutoff valve to dry out and fail sooner. Just thaught id throw that out there. :naughty: :naughty:

  • cowboyona426

Posted April 04, 2005 - 09:29 PM

#27

Do the 450 cam mod, it's well worth it. No one that has done it has been sorry, the only sceptics are the one's who haven't done it! The 426 will make a great trail bike with a few minor mods.

1. Gearing- I run 13/52, but am considering 14/52.
2. Rad braces- you'll be glad you have them when you crash hard
3. Bark busters- save your levers and your fingers, and keeps trees from applying the front brake unexpectedly

I've got a really good how-to post on the 450 cam install, but its one "one of those other sites" so if you want the link PM me. There is also a PDF floating about that's pretty helpful too. Satch, that means you buddy :naughty:

  • kizzle426

Posted April 04, 2005 - 09:56 PM

#28

The reason i let the gas get out of the carb is because I don't get to ride as often as I would like. Never heard about the rubber float messin' up though. I might stop doing it now. I don't want to hurt her :naughty: !!

  • buck_y_lee

Posted April 04, 2005 - 10:37 PM

#29

Do the 450 cam mod, it's well worth it. No one that has done it has been sorry, the only sceptics are the one's who haven't done it!

Excellent observation. Here's another one - the only ones who haven't done it are the sceptics. Duh!

No doubt the cam mod is nice, but it's hardly necessary. And for a new thumper owner, it's a parts plus labour expense.

Whatever floats your boat I guess.

  • felony

Posted April 05, 2005 - 01:14 AM

#30

i feel your pain .after getting off a kx250 i was thinking what in the world have i gotten myself into,i remember cursing and and damn near passing out try to getmy 01 426 started.i have fouled plugs left and right.taking off tank to replace is no fun either.but now evrything is 2nd nature,i love the bike.i can even change a plug in less than 10 min..lol

  • shanet1975

Posted April 05, 2005 - 04:26 AM

#31

It does sputter when decelerating. And it does hold the idle for a while before it goes back to normal. Would the fuel screw not being right have anything to do with the starting issue. My wife is picking up a few spark plugs today so hopefully that will help out. Where is the fuel screw located. Is it just like an idle screw on a 2 stroke?
Thanks again...





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