shifting quicker does NOT mean shifting sooner in the RPM range. It means you need to learn to bang from one gear to the next in a shorter amount of time.

 

This topic has always intrigued me as the amount of varied answers that are given! LOL! There are some views in this thread that just don't make sense.

The reason that I say this is because of my experience with my Z and reading about people hitting the rev limiter which caused me to think that's what I was experiencing and quit trying to fine tune my jetting. I am the first to admit if I had thouroughly followed the DIRECTIONS that came with my jet kit when I started I would not of even thought of this rev limiter crap!

The only mods that I have made to my Z are the addition of a CFM aluminum topless airbox,K&N airfilter with water repellant Outerwear and a Stage 2 Dyno jet kit, That's it as far as the motor goes! When I bought the airbox Neal had suggested a 146main with the needle in the 3rd slot. Man I thought this thing was awesome! But like so many of you I was concerned with this flat spot and after reading posts I too thought it was the rev limiter and was just going to have to live with it! Ahh but us old farts can't do that! So after many futile attempts to correct the jetting I was hit with a Brain Storm! Read the damn instructions !

Those people at Dyno Jet are pretty smart and I found out just how smart after I did some of there diagnostics! I was way to lean and all it took was installing the 155main jet and no more flat spot! No more so called rev limiter issue! I just got back from a ride on my Z and NOW she FLIES!

I know that most of you have seen a dyno chart and know that torgue is more important than HP, so if you look at all the Dyno charts that you can find of a STOCK displacement Z the torgue peaks on an average of 7200rpm so why in the he11 are you trying to get past 9000rpm which is where the rev limiter is set to kick in?

Z4ZZZ, I can tell you beyond a shadow of a doubt that you have something WRONG and that you would be better off putting the stock sprocket back on like has been suggested and ask for some help in finding out what it is! Then I guaranty that you will be dusting your buddy but don't even think that if you meet some old fart on what looks like a stock Z ! LOL!

 

Hey Gramps,

I'm a few years short of 40 (just a few) and I'm sure you've got a few years on me, but that won't keep me from responding to your post and letting you know that you may very well be way off the mark. I have always been nice to my elders and I plan on keeping that record intact. There may be a few guys on the forum dealing with a jetting problem, but if you want to experience what these guys are concerned about, well...ADD AN AFTERMARKET PIPE! I didn't see it in your list of mods. Here's the deal...I've listed my mods earlier and posted what I thought was a "spot-on" post. I didn't hit the print icon and frame it for the office, but nonetheless I thought it was rather poignant. I have the K&N adapter (pro-flow), K&N filter with Advantage outerwear, Dyno Jets jetting kit, open air box, AND and a full YOSHI EXHAUST. I read the jetting instructions and also went to Yoshimura's web-site to figure out the jetting (which by the way was very different than the suggestion of the mechanic at the local dealer). I went with the Yoshi numbers and it is....PERFECT. What I am experiencing and probably what others in my situation with the same amount of mods (inclusion of pipe) are experiencing is THE REV LIMITER. The same thing you experience in reverse...well...it happens as you rip to the end of first and second. AND it comes on quick...now I'm not going to repeat my post above, as I've already stated...it's a beauty. Add the pipe Gramps and you'll wake that Z up much more so than it is already. NOW...if you already have the pipe and forgot to list it, (could be age related) and you're not experiencing this....GO FASTER! I hope this thread is taken as lightly as it is intended to be.

Peace,

bdiddy

 

bdiddy, are feeling insecure? LOL! Your post was more ontrack than alot of the others and very well stated. I am sure that you have your Z set up well and my point was that with stock gearing and an intact stock exhaust I found for me that it was a jetting issue. Now, since I used to roadrace and drag race motorcycles I might be at an advantage as I always get a feel for what the engine is doing and shift accordingly! I don't even think of it I just do it, sort of what you might call riding the curve and staying at the crest of it. I am sure that you have that same sort of feel as well. Gearing is also a very big issue as any racer would know and they also have a stack of rear and front sprockets so that they can taylor there machine for whatever the race needs not to mention a variety of carb parts.

I know what the rev limiter feels like, just like a stutter box, but with the corrections that I made to my jetting I no longer hit the flat that preceeds it. As far as adding a pipe, I have thought about it, but for now I am going to turn my attention to the suspension. These bones just ain't what they used to be! LOL!

 

It's all good. Insecure, I don't think so. I'll ask my shrink [img]i/expressions/face-icon-small-wink.gif[/img] . As I posted in my first post...I didn't hit the limiter after the first half hour of riding it with the mods. If you ride well by feel (cars, streetbikes, karts..) well, you know... If what these guys are experiencing is anything like what mine does if I ignore the sound of the motor telling me SHIFT..and then..SHIFT AGAIN!! It'll stutter like a nervous Mel Tillis....see, I am almost 40. Good post Gramps. Ciao!

 

If you have aftermarket exhaust AND ride WFO, you will experience the rev limiter. The best cure in addition to a rev box is to add a tooth to the front. The machine LOVES IT!!! The quad will pull much longer without hitting the rev limit. Even the mags that tested the Z with the 450 kits months back said the machine could definately use a 15 tooth front. These quads don't need a 450 kit to benefit from a 15 tooth sprocket. Just spend the 15-25 bucks and find out for yourself.

 

Heck, Ive hit the rev limiter and my Z is stock except for the pee shooter on the muffler which is now removed. Out on the dunes in NV, with only Sand Shark paddles climbing the Sand Mountain I nailed the rev limiter! At first I thought the motor was coming apart, sitting on a nice steep uphill I quickly realized the only way to overcome this was to shift sooner. As I learned my motor more I have had no other problems at the dunes. But the 15 tooth sprocket sounds like a nice, cheap mod. I was going to buy the CT pipe but after reading the Dirt Wheels shootout I can not justify spending $500-$600 on a system for just a couple of more overall HP, plus then having to mod the ignition to keep away from the dreaded rev limiter.
PD

 

If you put the 15 tooth on the front ultimately the quad is not as quick, BUT (and that's a BIG BUT in case you didn't notice) we are talking about limited traction and useable power. The 15 tooth will physically slow the quickness of the quad, but since the quad has enough torque to roost the tires even with the 15 tooth it may be easier to deal the slower revving gears (mainly 3rd, 4th, and 5th) and have "longer" gears down low.(1st and 2nd). In some conditions ultimately making the quad quicker AND faster. Hopefully we can put this to rest. The 15 tooth does not eliminate the limiter problem it just makes it much less of a threat.

Front sprocket bigger=faster top end, slower bottom end, slower revs, longer usable gear before hitting rev limiter
Front sprocket smaller= slower top end, quicker bottem end, faster revs, shorter usable gear before hitting rev limiter([img]i/expressions/face-icon-small-happy.gif[/img] MY PERSONAL FAVORITE[img]i/expressions/face-icon-small-happy.gif[/img])

I like the feel of the quicker revving motor and just bang the shifts off quicker. (for now) Others like the feel of a longer gear and the luxury of shfting later.

NOW if you race, you're setting up your gearing to accomodate the track. Me? I'm just out f 'n around.....and the quicker the better!

Peace and I'm out!

 

call me crazy but i thought the rev limiter surved a purpose, to keep the engine from over reving and over heating i might be wrong. i am a little young and some of you have 30 plus years on me but i have always thought that the engine cut off for a reason.

how high can you rev this thing( the z) befor you blow the motor up?

 

Yeah the purpose of the rev limiter is to keep the squids from reving out 1st and 2nd since they never seem to leave those gears. Anyone who really rides hard will be very disappointed when they are constantly having to adjust their shifting to compensate for the limiter. As I have said before shifting from 2 - 3 when climbing a very demanding hill (not ant hills) to avoid the rev limiter in 2nd will just cause the bike to bog. Then you are stuck downshifting to 2nd and hitting the limiter again. I don't own a Z400 (my friend does) but if I did I would fix this problem at whatever cost because it sucks!!