Smoother Acceleration

Hi,

I have a 2001 yz426. Is there any way that I can smooth out my acceleration? I have been trying to set my yz up for trail riding and the throttle is just too touchy right now. I already have a 12 oz. flywheel weight and a 13T front sprocket. Any help would be greatly appreciated.

James

Try the FMF powerbomb and "Q" muffler setup. All I do is Enduro's and trail riding on my YZ400. The flywheel weight, gearing and especially the exhaust smoothed it out the bottom real good. We're not talking DR400 smooth, but it made it alot more managable in the nasty stuff. Another trick is to bump the idle up a bit and run your clutch with almost no play. That way your disengaging the clutch alot earlier in the pull for tight, twisty stuff and for unexpected corrections. Just don't adjust it too tight or it won't fully engage and slip. Hope thi helps. -Adam-

You may consider changing to WR exhaust cam timing.

Thanks Adam and Hick,

I will definately go with the new exhaust. In fact I already have it in my garage. It's going on tommorrow! I'm also considering going to a 51 rear sprocket. Hick have you or anyone you know switched to wr cam timing? That sounds like something I would like to try. I just do not know how to do it and I am wondering how it has worked for others.

Thanks again,

James

A good test would be to ride somebody's WR.

IMO the different cam timing smooths that lower-midrange rip the YZ has. I can actually hold a long wheelie much easier on my pal's WR, and since he has WB exhaust, YZ jetting and I'm talking about 3rd & 4th gear then I'd attribute the difference to the cam timing.

To try this out just advance your exhaust cam one tooth. That would mimick WR cam timing.

Thanks Hick,

I just checked into how the wr side adjusts their timing. They turn the exhaust cam clockwise one tooth. Since I have a yz I should turn the exhaust cam counter clockwise one tooth instead of clockwise? I am pretty sure this would be the way to do it, but would like to know for sure before I tear into my bike. Here is the link I found http://www.off-road.com/dirtbike/jun99/hobbs/

James

Yep. Just follow the advice on how to change a WR to YZ timing, only move the cam in the opposite direction.

Since the motor spins counter clockwise (from that perspective), just like the rear wheel, moving the exhaust cam one tooth counter clockwise puts the cam ahead of the crankshaft, advancing the timing one tooth.

You may or may not prefer it this way, but it does make a noticeable difference in the power characteristic. You get more torque at lower rpms, which IMO smoothes out how the motor "gets on the pipe," as it were.

Anyway, based on your post I think it may be worth a try, especially if you need to check your valve clearance, and perhaps check what size shims you have (so you can order replacements in advance), anyway.

AS far as smooth goes, going with the 13 counter seems like it would make the hit worse. Too much leverage. Cheap experiment, WR time the cams & go back to the 14 counter. This should simulate riding "a gear up". If you did the bk mod, undo it.

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