Maintenance throttle

[Lychee]

I discovered on a recent ride that my ninjette jolts very noticeably from 0% throttle to 1% throttle if not done extremely slowly or in conjunction with the clutch. Sometimes the chassis will become unstable, especially if I am leaned over mid turn when I begin my roll on. I do plan to look at the carb, chain, and cush drive for any possible needed maintenance, but I am not beyond the idea that the problem is between the throttle and the seat.

Initially, I read that when tipping in, the brakes should be trailing and throttle should be off to compress the forks and shorten the rake to facilitate the tip in. Keith Code says that once you crack it open you should start applying a consistent roll on immediately throughout the rest of the turn, which seems to agree with what I read (throttle off on tip in). However, there are other opinions that say that you should have a minimum neutral acceleration, or "maintenance throttle" while tipping into the turn in order to take up the chain slack and stabilize the chassis. Well that could be the solution to my problem.

How do you (personally) apply the concept of "maintenance throttle" on your bike, if at all?

[rojoracing53]

Uh your over thinking this a bit.....well maybe a lot

I will agree the hesitation from 0-1% is Efing annoying beyond all belief because I've dealt with it on the fuel injected R6's. As for all that other stuff there is no one right way only a riders preferred method.

First my bike currently has no 0-1% jump or delay is what I'd called it but it did do a mod to my carb that created the problem so I removed the mod. The mod I'm referring to is the one where you use like a #50 something drill to drill a hole in the plastic vacuum slider thingy to do.....well I can't even remember but right after my had the problem with 0-1% throttle opening. I pulled it back apart and closed up the tiny holes I had created and the problem went away.

Just figured I'd though that out there just incase you did that same mod.

I alway thought off it as a lean condition because instead of it surging like you describe it felt more like a reference thing like I opening 1 then 2% over a second of time and still getting nothing. Then as I hit 3% I all of a sudden get the full effect of 3% so it can be called a burst or I prefer delay response.

Good luck fixing it and let us know if you do.

[Motofool]

Jon,

Hardware related:

Check slack in both throttle cables.

Check play between sprocket cushion and rear tire.

Check chain tension.

Software related:

Complete all your braking and downshifting before entering the turn; at that point (entering speed) there is no place for zero throttle, since your bike should be moving without any deceleration (no gas = bike slowing down).

If you like brake trailing into the turn, use some rear brake rather than front, that will keep the transmission loaded and the deceleration-acceleration transition will be smoother.

As soon as possible after you enter the turn, open the throttle enough to increase the speed around 3 mph per each second on the turn; that will set the suspension the best possible at around 0.15 G.

[Alex]

Maintenance throttle on a 250 = full throttle. Acceleration on a 250 = full throttle. Engine braking = no throttle. Any setting between the two is irrelevant.

[Lychee]

Originally Posted by rojoracing53

...

Jason, I don't have the modification, but I am hearing, check for a lean condition and barring that, deal with lag. OK. But you didn't say what method you use.

Originally Posted by Motofool

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Thanks, seems to make sense. Sounds like you enter with the neutral throttle method.

Originally Posted by Alex

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Got it, Alex is the master- direct all questions to him first for the most realistic answer.

[alex.s]

the process goes something like:

slow the bike down

turn the bike

go fast

repeat.

[rojoracing53]

I undid the method I used to created the problem which was plug the holes I drilled in the plastic slides. I didn't change any jetting or anything else at all.

[Lychee]

Originally Posted by rojoracing53

I undid the method I used to created the problem which was plug the holes I drilled in the plastic slides. I didn't change any jetting or anything else at all.

Ok, say for your hesitating R6, when you enter a turn is your throttle off or throttle minimally on?

[rojoracing53]

Originally Posted by Lychee

Ok, say for your hesitating R6, when you enter a turn is your throttle off or throttle minimally on?

"Enter a turn" has like three stages if I were to break it up(no I'm not going to tell what the three stages are because then I'd have to think of name and description for them and I'm to damn lazy) at least the first stage I'm totally off the throttle. Then when I'd go to crack open the throttle to even out the bikes weight distribution there would be a delayed response like I described in my earlier post. When the bikes at full lean and 13,000+ rmps it causes all kinds off hell for your delicately establish balance of traction. Graves from graves Yamaha thought I was being overly sensitive at first but after we fixed the problem with some ECU black magic(I'm not going into details because again that would require thinking) I was able to drop a full second off my lap times for qualifying.

Among the pro level riders I was thought of as extra critical with bike controls like clutch & throttle response which is also why I hated slipper clutches and traction control. When I'd ride on endurance teams and have to ride other people's bikes and I'd come in after the first session and make few changes to the controls and everyone would always say it was better. I think most people just don't notice so they don't care about those little things.

Sorry if I seem reluctant to your question about how to ride, its just I was never taught myself so I can't just repeat what someone else taught me, I have to think it up myself and I tend to think in to great of detail to spend all day writing a book about turning in

Join us for a ride sometime and ask me then, I'm much more willing to talk then type but be prepared for some because although there's no such thing as a stupid question, some of them are just to damn funny not to laugh inside

[csmith12]

Originally Posted by Lychee

However, there are other opinions that say that you should have a minimum neutral acceleration, or "maintenance throttle" while tipping into the turn in order to take up the chain slack and stabilize the chassis.

Customize your bike to how you want to ride it, your throttle cable and chain slack are two big factors.

I posted in a thread some time ago this simple fact. When accelerating your chain is tight at the top, when on the brakes you chain is tight on the bottom. Where does the slack go? Your a**.... How do you get rid of it? Something has to be adjusted; either your chain slack, throttle cable slack, cush drive (add or remove shims) or your throttle hand.

Giving the throttle cable more slack will create "time" in your transition between brakes and throttle. And that "time" could also be labeled as the "maintenance throttle" that you are describing.

Another thought... Maybe have a look at the preload on your rear shock. The harder it is, the more your gunna feel stuff. Your carbs in sync?

[Havok]

For me for street riding on turns i like to be under power of some sort when i start a turn. Its situational for me though if i am just using throttle or if i am slipping the clutch. I found on the ninjette and on the 600 i had to slip the clutch a lot esp 1st gear. They were both a bit jumpy.

I think just working on throttle and clutch control will help smooth things out for you. If you are breaking late and the rpms are dropping and you are not getting on the gas soon enough stop doing that, Breaking late is great for passing people but is not the fastest way around a corner or a track.

The Keith Code method you are talking about is for a quick in quick out corner. Eliminating how long the bike is leaned over. Great for shaving off some tics on your lap time at the track, Not the best way to take a corner on the street.

[csmith12]

Originally Posted by Havok

The Keith Code method you are talking about is for a quick in quick out corner. Eliminating how long the bike is leaned over. Great for shaving off some tics on your lap time at the track, Not the best way to take a corner on the street.

^^ Yea kinda, just don't loose site of what trail braking is really for. Which is setting corner entry speed (or passing in a race). Code labels this transition as "Get back to the throttle as soon as possible, not at entry, not at apex and not at any particular part of the turn. But as soon as the rider can." In other words... after steering is complete and the rider is comfortable with the speed.

Think about this, some riders are hard on the brakes setting their corner speed slower than what they intended. Then what happens? They hammer the throttle to get the speed back. In this case, it's not very smooth. While on a 250, it's not a huge problem most of the time but even a 250 at it's very limit of traction can go down like this. Some of us know this...

[choneofakind]

Lychee,

I think it might serve you well to go to a parking lot in first gear, and practice smoothly getting that transition from closed throttle to barely opened throttle. In my experience, it's most noticeable in first gear, and once you master the on/off in first, you should be much smoother when entering turns and giving maintenance throttle.

I'm not touching the cornering stuff because those 3 are way better at it than I am...

Also, I second one of Hernan's suggestions: double check for excessive slop between the cush drive and the rim. That causes some herky-jerky feelings when transitioning from no throttle to throttle.

[Havok]

Originally Posted by csmith12

^^ Yea kinda, just don't loose site of what trail braking is really for. Which is setting corner entry speed (or passing in a race). Code labels this transition as "Get back to the throttle as soon as possible, not at entry, not at apex and not at any particular part of the turn. But as soon as the rider can." In other words... after steering is complete and the rider is comfortable with the speed.

Think about this, some riders are hard on the brakes setting their corner speed slower than what they intended. Then what happens? They hammer the throttle to get the speed back. In this case, it's not very smooth. While on a 250, it's not a huge problem most of the time but even a 250 at it's very limit of traction can go down like this. Some of us know this...

Have always thought of trail braking as enter the corner while you are breaking trailing off as you go through staing on the gas. Doing it before you turn in is just setting your speed carefully as in knowing how to properly use your front brake.

I agree with your second statement hard on the brakes then hard on the gas is not the best option I just call that late braking done right you can make a pass, done wrong and you hit the dirt, not really something needed on the street for any reason.

He needs to set his entry speed earlier and not worry about braking hard or trail breaking as he turns. Set his soeed, turn in, roll on at apex. Master that for turns on the street work on the rest racing or on the track.

[csmith12]

Jeff, I wasn't really directing my post at you though . Indeed, there is a time and place for everything.

I will have to put a cam on my throttle hand. I bet I take my fingers off the brake as I roll on in a very relaxed way. That may create some overlap of brake and throttle. Dunno, never really pay that much attention to such fine detail at that point in cornering. My focus is on where I am going. lol Otherwise, street or track I would say I am rarely on both at the same time, less the slow speed stuff.

[alex.s]

a lot of people forget that you can still make very large steering inputs while at WOT.... sometimes "get back on the gas asap" means "dont let off the gas

[cbinker]

if you have stock jets, it is going to lag in the low end. i re-jetted last summer and it made a world of difference in throttle response.

[Lychee]

I did some work on the bike and the jerky on/off transition is pretty much gone now. I guess it was a mechanical problem after all. Here is what I did:
-valve adjustment
-adj mixture screw from 2 to 2.25
-shim cush drive
-adjusted chain tension
-adjusted throttle cable tension

Thanks for the suggestions guys. Big help.

[csmith12]