Flat spot at WOT

[scosgt]

So I have the 2012 SYM HD 200 EVO running really nice now.
I rode the parkway back and forth, no issues. Hit 67 on an upgrade, ran out of space but it had some more left in it, probably hit 70 with the 12g sliders, they do reduce the top end a few MPH.

However, at WOT there is a bit of a flat spot. Back off the throttle slightly and it accelerates, just not when held at WOT. The back off amount is like almost nothing, just getting it off the stop is all.

Is this possibly a throttle cable adjustment, or a carb adjustment, or?

No hesitation except at WOT when on the parkway or merging onto the parkway. Low speed accel is GREAT.

Any ideas?

[kz1000st]

It's fuel injected isn't it? I would have said a slightly bigger jet otherwise. Oddly enough my 250cc scooter does the same thing but I marked that down to the oddities of a diaphragm carburetor. What shape is the air filter in?

Nope, just looked it up. It has a carb. Slightly larger main jet then.

http://www.motorcyclistonline.com/2012/sym/hd/200_evo/specifications/116445/05/engine.html

It might be a slightly lean set up for EPA purposes.

[scosgt]

It's fuel injected isn't it? I would have said a slightly bigger jet otherwise. Oddly enough my 250cc scooter does the same thing but I marked that down to the oddities of a diaphragm carburetor. What shape is the air filter in?

Nope, just looked it up. It has a carb. Slightly larger main jet then.

http://www.motorcyclistonline.com/2012/sym/hd/200_evo/specifications/116445/05/engine.html

It might be a slightly lean set up for EPA purposes.]

Thanks

Someone else on a different forum said the same thing. Not sure if I am going to try that or just leave it alone.

Air filter is new by the way.

[kz1000st]

I also have noticed much better response on my 250 after adjusting the valves. Since a Diaphragm carburetor depends on engine vacuum you may want to double check your valve clearances,