The New YZ400/426/450 FAQ's/Mods Sticky

Because there is only a certain amount of space available at the top of the page, there's a limit to how many stickies can go there. There are, however, a number of great threads bobbing around in the system that can and should be more accessible as references. I've been thinking about this, and a way to make the really huge DCM thread more usable for quite a while now. Maybe it's the moon, but BW, Eddie Sinsneros, and I all came up with the same basic idea more or less at once. Quickly, it's an indexed list of good threads covering different subjects that come up frequently. That way, a member won't have to search for every old thread he needs, and the Index header won't need as many stickies.

If you have a nomination for a subject or a particular thread that you'd like posted, either a popular mod like the cam thread, or a too frequently asked question, like oil and red, glowing headers, let me know.

If you think you know of a better thread or other link for one that's already posted, let me hear that, too.

Let's have your comments.

if you unplug the throttle position sensor it gives a great boost in power on the bottom end

Your link didn't work. Search results expire in 30 minutes. Link directly to the page. But I'll take the vote for TPS info.

Accel. Pump wiring mod. I can't believe the difference this made to my 06' YZ450. The 06' does not require any mod to the diaphram rivet and after wiring it up and installing a #70 leak jet the bike runs perfect. This is an inexpensive and easy mod that every rider will benefit from. It gives the bike instant throttle response from idle to wide open without any bog, stumble, hesitation, or hicup.

Cam mod, breather tube re-route, maybe interchangeability between the 400/426/450 parts, jetting, AP mods, Rekluse installation/adjustment, valve adjustment, swingarm/subframe chainguard, suspension settings, rebuild/replace timelines...just throwing random things out there as they come to mind.

RMZ throttle cables will work on the 426. 04-05 450 cables dont.

Accel. Pump wiring mod. I can't believe the difference this made to my 06' YZ450. The 06' does not require any mod to the diaphram rivet and after wiring it up and installing a #70 leak jet the bike runs perfect. This is an inexpensive and easy mod that every rider will benefit from. It gives the bike instant throttle response from idle to wide open without any bog, stumble, hesitation, or hicup.

Does anyone have any additionational info on this Accel Pump Wiring mod or any experience afterwards? I'm thinking about doing it, but all I've seen is a writeup on it done to a CRF. Do you need to remove the carb? Can I do just the wire mod and not need to change the leak jet?

Thanks!:lol:

Does anyone have any additionational info on this Accel Pump Wiring mod or any experience afterwards? I'm thinking about doing it, but all I've seen is a writeup on it done to a CRF. Do you need to remove the carb? Can I do just the wire mod and not need to change the leak jet?

Thanks!:lol:

I did it on my 06 YZ450F. Just follow the instructions for the Honda. There is no need to do anything to the rivet on the diaphram. I did not change the leak jet at first, but later changed it to a 65. Really did not notice any difference between the 2 leak jets. To do the mod I did not remove the carb from my bike. The mod is sweet and very much worth doing.

if you unplug the throttle position sensor it gives a great boost in power on the bottom end

Is this for all the bikes the 400/426/450?

No...

No...

ok.. which one is it for?

IMO, none.

How about a detailed starting drill for the 400/426, it seems that a lot of people that buy them are asking how to start them. Dubach Racing used to have a link to the Yamaha site where there was a video of the starting procedure for hot and cold starts. I tried to track it down through both sites but did not have any luck. It was awesome help when I bought my 400.

How about a detailed starting drill for the 400/426, it seems that a lot of people that buy them are asking how to start them. Dubach Racing used to have a link to the Yamaha site where there was a video of the starting procedure for hot and cold starts. I tried to track it down through both sites but did not have any luck. It was awesome help when I bought my 400.
Believe me, of that video were still up on their web site, I'd have a link to it. I wish I had downloaded a copy.

I wrote to Dubach Racing, and they replied that Doug had spoken to someone at Yamaha who told him that they would repost the video. It hasn't happened yet, but I'll keep looking.

i have 426, how can i get rid of the decompression

i hear you can swap cams from frist year yz450 to the 426

How about a detailed starting drill for the 400/426, it seems that a lot of people that buy them are asking how to start them. Dubach Racing used to have a link to the Yamaha site where there was a video of the starting procedure for hot and cold starts. I tried to track it down through both sites but did not have any luck. It was awesome help when I bought my 400.

I found it and posted it under Miscellaneous at the bottom of the page.

I want to thank Doug Dubach for his personal involvement with this. Yamaha shunted the video off its web site when they rearranged it about a year ago, most likely thinking it wasn't being used, or wasn't current enough. I wrote to Dr.D, knowing from experience that there would be someone there who would at least read the e-mail and respond. It was Doug Dubach himself who contacted Yamaha about this, and even if it really was simple and easy for him to do, there was really no reason for him to feel compelled to bother with it. Nevertheless, he got his contact at Yamaha to repost it and his staff forwarded the links with permission to post it here.

Many Thanks Dr.D :applause:

Because there is only a certain amount of space available at the top of the page, there's a limit to how many stickies can go there. There are, however, a number of great threads bobbing around in the system that can and should be more accessible as references. I've been thinking about this, and a way to make the really huge DCM thread more usable for quite a while now. Maybe it's the moon, but BW, Eddie Sinsneros, and I all came up with the same basic idea more or less at once. Quickly, it's an indexed list of good threads covering different subjects that come up frequently. That way, a member won't have to search for every old thread he needs, and the Index header won't need as many stickies.

If you have a nomination for a subject or a particular thread that you'd like posted, either a popular mod like the cam thread, or a too frequently asked question, like oil and red, glowing headers, let me know.

If you think you know of a better thread or other link for one that's already posted, let me hear that, too.

Let's have your comments.

How grading or suggesting a skill level to do the sticky mods? Like: a 3 out of 5 for the wr tranny to a yz swap mod? 5 being the most difficult?

Worth considering.

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