Im a little concerned about my ignition system.


8 replies to this topic
  • Skithis

Posted February 17, 2008 - 05:29 PM

#1

Well i bought this 426 about 2 weeks ago and its been nothing but problems. Ive got most of the problems sorted out but 1. Heres the deal...

When i first got the bike we couldnt get it started. Found out the plug was toast. I went and bought a champion "racing" plug. Put it in. Bike starts great several times. At most 3 kicks cold. Then all of the sudden yesterday it takes me an hour to get it started after wire brushing the plug off. Today it wil not start. Ive kicked and kicked. I checked spark and the plug wont spark. So i take a NGK BR8ES that i have out of my jet ski and put it on the cable and it sparks like crazy. So then im sure its the plug. I take the champion plug that wont fire on the bike over to a 1960s snowblower and plug it in, it fires like lightning. Atleast 10 times brighter than the bike. I dont understand, is the ignition always this weak? why wont the plug fire on the bike but on a 5hp snowblower like lightning. What is the best plug for the 426?

  • Speedracer747-400

Posted February 17, 2008 - 05:51 PM

#2

The Yamaha service manual calls for an NGK CR8E or a Denso U24ESR-N. I would recommend sticking with NGK. I'm running an NGK CR8EIX which is an iridium version of the standard plug. It costs a little more, but will last longer.

  • Speedracer747-400

Posted February 17, 2008 - 06:05 PM

#3

This might help a little to make sure you have the starting sequence down. If your bike is jetted correctly and you follow the starting method below it should start first kick every time. You can find this in the stickied section near the top under common threads.


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

Note: Video may take a few minutes to download.

  • 642MX

Posted February 17, 2008 - 06:10 PM

#4

Well i bought this 426 about 2 weeks ago and its been nothing but problems. Ive got most of the problems sorted out but 1. Heres the deal...

When i first got the bike we couldnt get it started. Found out the plug was toast. I went and bought a champion "racing" plug. Put it in. Bike starts great several times. At most 3 kicks cold. Then all of the sudden yesterday it takes me an hour to get it started after wire brushing the plug off. Today it wil not start. Ive kicked and kicked. I checked spark and the plug wont spark. So i take a NGK BR8ES that i have out of my jet ski and put it on the cable and it sparks like crazy. So then im sure its the plug. I take the champion plug that wont fire on the bike over to a 1960s snowblower and plug it in, it fires like lightning. Atleast 10 times brighter than the bike. I dont understand, is the ignition always this weak? why wont the plug fire on the bike but on a 5hp snowblower like lightning. What is the best plug for the 426?



Champions are not the best choice for YZF's.

Use a NGK CR8E in the 426. You can also use a CR8EK or the iridium version.

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  • William1

Posted February 18, 2008 - 03:17 AM

#5

If you are fuel fouling the plug, a CDI may not be able to fire it where as a magneto system like on a lawn/snowblower engine can.
As others pointed out, review your starting procedure. Attempt to use the least fuel to get it fired off. Use the OEM rec. plug.

  • Skithis

Posted February 18, 2008 - 06:35 AM

#6

Sounds like a plan. Im gonna try a NGK CR8EK and see what happens. Other people have told me that champions were junk but at the aircraft business i work at all we use is champions. They run great in an airplane. Ofcourse they are $25 a peice also.

  • endurodog

Posted February 18, 2008 - 07:22 AM

#7

Correct plug is the best place to start. A bunch of guys here in Colorado were having problems with their 426's fouling plugs in the winter. We get oxy fuels then. They started running race gas and the problem went away for them. Just a thought.

  • todds924

Posted February 19, 2008 - 05:10 PM

#8

Stator may be on its way out also.

  • Skithis

Posted February 20, 2008 - 09:36 PM

#9

stator is less than 2 months old. Moose 45 watt lighting stator. Anybody know what the pickup gap is supposed to be on this beast?





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