Roll Starting a 426??


25 replies to this topic
  • Raven1911

Posted December 07, 2005 - 04:53 AM

#1

Is it possible to roll start a 2001 YZ426? If so what is the procedure? I haven't tried yet since I don't know exactly how and don't want to damage the bike. I figure I could start coasting down a hill with the clutch in and then let it out :applause: ???

  • sirthumpalot

Posted December 07, 2005 - 04:58 AM

#2

Easiest way is to get it rolling with the clutch in and the bike in gear, pull the compression release and let the clutch out. As soon as the motor spins release the compression release. If you stall it in the air then depending on your situation it may relite on landing without the compression release being pulled in, but if it doens't then the back wheel will lock up so it's safer to just pull in the release until the motor starts to spin.

  • kawirider

Posted December 07, 2005 - 05:48 AM

#3

My dads WR has manual decompression and I just put it to TDC real quick and chuck it into 2nd from neutral once I get enough speed. Works every time. What kind of damage could come from bump starting anyway?

  • ESC

Posted December 07, 2005 - 07:01 AM

#4

I've been able to bump start mine going downhill a couple of times without the compression release. Other times it just locks up the rear tire.

  • rdefonce

Posted December 07, 2005 - 07:34 AM

#5

Is it possible to roll start a 2001 YZ426? If so what is the procedure? I haven't tried yet since I don't know exactly how and don't want to damage the bike. I figure I could start coasting down a hill with the clutch in and then let it out :applause: ???


Yes you should be able to, without damage to bike BUT a good-sized hill is usually required (at least in my experiences.)

You've got the basics down, but I'll add that it helps to put bike in at least second gear (1st gear - it'll probably just skid to a halt.) Also, jump on seat when letting clutch out so more traction to rear wheel.

I tried the compression-release technique but had less luck with that.

  • Butta

Posted December 07, 2005 - 08:04 AM

#6

Yep, like they have said, 2nd gear works the best. I haven't ever had a problem doing it, and it hasn't ever required a very big hill on my '98's, and an even smaller one on my '05.

  • grayracer513

Posted December 07, 2005 - 08:21 AM

#7

Learn to use the compression release as suggested and you'll find that it will start on a pretty slight grade easily enough. The trick to it is in easing off on the release to get the engine started turning, instead of letting go quickly. Then, gently roll the throttle open just enough to get the engine to catch and pull the clutch in as soon as it starts.

Another thing that will help is to put it in gear before you roll it off and back it up against compression. That gives it a free turn and a half before the next comp stroke.

No damage will occur from this. It's only when the release is operated at engine speeds above idle that it's dangerous.

  • DigilubeJay

Posted December 08, 2005 - 01:50 AM

#8

Mount up an auto-decompression exhaust cam, and bump start it like a two-stroke any time you want. Reach down and start the beast with one hand after installing the cam as well. It completely changes the attitude of your bike, for the better.

  • Raven1911

Posted December 08, 2005 - 05:24 AM

#9

Thanks I will give the 2nd gear thing a try and the decomp thing as well....

A buddy of mine put my decompression level below my clutch and said it was better there because if I crash it won't rotate up on the bar and hit my hand. I am thinking of relocating it above because I don't think I can roll start, which I do frequently, with the decom level below. It would just be hard to use both levers. Where are all your decom levers located?

  • Fizz

Posted December 08, 2005 - 05:45 AM

#10

i'm gone buy a thumb operated decomp lever ... its hard to use the clutch and decomp at the same time i think ..

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  • sirthumpalot

Posted December 08, 2005 - 05:54 AM

#11

Thanks I will give the 2nd gear thing a try and the decomp thing as well....

A buddy of mine put my decompression level below my clutch and said it was better there because if I crash it won't rotate up on the bar and hit my hand. ....<snip>....


If you're crashing to the point that your levers are spinning around the bar, and you're still holding on to the bar at that point, then you may want to consider rethinking your crash strategy and include the option to bail out. :applause:

  • ESC

Posted December 08, 2005 - 06:47 AM

#12

If you're crashing to the point that your levers are spinning around the bar, and you're still holding on to the bar at that point, then you may want to consider rethinking your crash strategy and include the option to bail out. :ride:


haha...thats ONE thing I've become an expert at! I may not ride like a pro but I can sure crash like one!! :applause:

  • grayracer513

Posted December 08, 2005 - 08:02 AM

#13

A buddy of mine put my decompression level below my clutch and said it was better there because if I crash it won't rotate up on the bar and hit my hand.


i'm gone buy a thumb operated decomp lever ... its hard to use the clutch and decomp at the same time i think ..

Locating the decomp lever above the clutch lever is done to avoid having it stick you in the leg if you get caught between the bars and tank, which strikes me as a good deal more likely than having the levers roll up on your hand, especially if you heed Thump's advice.

As far as ease of operation, pull the clutch with the last three fingers, and the decomp with your index; should be easy, particularly if the decomp lever is set at a fairly close angle to the clutch lever.

Of course, as stated, the '03 cam upgrade is the way to permanently solve this whole problem. After you've had it for a while, you'll wonder why you ever waited.

  • Fizz

Posted December 08, 2005 - 08:31 AM

#14

*snip*should be easy*snip*


not with my tiny fingers .. :applause: :ride: :p

  • Fastest1

Posted December 08, 2005 - 02:51 PM

#15

Go for the auto cam and forget any negative problems you have ever had.

  • darksun27

Posted December 08, 2005 - 03:21 PM

#16

Thanks I will give the 2nd gear thing a try and the decomp thing as well....

A buddy of mine put my decompression level below my clutch and said it was better there because if I crash it won't rotate up on the bar and hit my hand. I am thinking of relocating it above because I don't think I can roll start, which I do frequently, with the decom level below. It would just be hard to use both levers. Where are all your decom levers located?

i have my compression release pointed back towards me on the kill swich side so i can use my thumb to operate it. i have a 04 yfz quad cam and it dosent work. i am guessing because my valves are out of adjustment

  • bxrjim

Posted December 08, 2005 - 07:09 PM

#17

I'm glad this subject came up. Grabbing the clutch and the compression release lever at the same time and letting go of the clutch and the comppression lever right after is the same way I bump start mine when I stall and I wasn't sure if I was doing any harm.

Now I know, Thanks Guys! :applause:

  • Raven1911

Posted December 08, 2005 - 09:16 PM

#18

Where did you get your cam?? Considering what is out today would you consider the 450 cam or the 426 cam? They make both right? :applause:

  • Butta

Posted December 09, 2005 - 09:17 AM

#19

The 450 cam is the only cam with the auto-decomp system. Believe what they are telling you, once you have it, you'll never understand why you waited so long....

  • DigilubeJay

Posted December 10, 2005 - 04:18 AM

#20

HotCams has an autodecomprsssion exhaust cam for the 400 and 426's.
Granted it is a bit more expensive than the stock OEM model for the 450's, but I have to feel that the quality of the HotCams product is of better grade then the mass production OEM cam.

I am also thinking that the lobes are cut ever so slightly different on the HotCams model than the OEM cams, as the HotCams model states that there will be a shim change that is automatic.....does anyone know this info? Gray? SFO? Rich? Anyone?
(HotCams autodecomp. for the 400-426 has 9mm lift / 265deg duration)





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