Low rpm poor throttle response?

[Dynofox]

I've been tinkering with my new toy (85 tri z) and it starts right up 1-2 kicks and will idle all day long but it doesn't have good lower rpm response. Just reving it up in neutral just off idle when I punch the gas it doen't seem to rev out as quick as I think it should. Once you get the rpms up it seems to rev fine though. While riding it I've noticed the same thing. If i'm going up through the gears it doesn't rev out good until the rpms are up there. I'm planning on getting a new air filter and possibly some boysen reed petals. Right now the bike has a dg pipe but the silencer is a stock unit off a different bike (a quad racer i believe since it has suzuki stamped into the side of it). Could the silencer be part of the reason? I'm planning on getting a dg silencer to go with the pipe pretty soon.

[TimSr]

Its unlikely the silencer is having any effect on performance. Most (2 stroke) are of a straight-through design, and even when filled with sludge, do not restrict or affect air flow. As long as the inside diameter of the silencer is not smaller than the end of the pipe, its not a problem.

Your off idle response is controlled by the idle air screw, which is on the ouside of the carb. This is the smaller one without the locknut. You start at about 2 turns out, and blip the throttle. Then you adjust it by 1/4 turn increments (in both directions), and blip the throttle after each adjustment until you get the best throttle response.

Id also do a half throttle plug test to see if the carb needle could use some adjustment. Another thing that can cause problems in this area is low compression caused by a worn top, end or rings.

Boysen Power Reeds will improve throttle response a little bit, though most of the effects are felt on the top side.

[Dynofox]

I'll give the air screw a try tonight, I'm pretty sure the problem isn't caused by low compression because it has a lot when trying to kick it over and it does start after 1-2 kicks. While doing a half throttle plug check can I do this while in neutral, or do I need to ride it? Thanks for the advice!

[TimSr]

You need to be riding so its under load. One of the mid gears or higher is better because its under more load, but not absolutely necessary.

[YTZ250N]

pull the carb off and clean it real good all the little circuts and pull the jets and clean them too. On the pipe I did a little "test" one time. I was re-packing My silencer which is a aftermarket straight thru type. I pulled out this big giant glob of old crap covered in oil. I re-packed it full with fiberglass, put the cap on bolted it on and ran around. when I would tap it out it wouldn't hit top R's so I pulled all the packing out and refilled it with about half as much, and guess what it R'ed right out. A little louder but it ran a lot better.

[Dynofox]

I played with the air screw and that fixed it right up! Right off idle it revs right up and runs much better. I didn't get a chance to take it out since i'm in the processes of working on the brakes and they're both off the bike right now. Again thanks for the advice! :-D

[84250r]

Most 2 strokes dont idle,and when they dont they seem to run better.