new oil made a big difference

[t-bone]

I'm not sure which made the bigger difference, dumping my gear lube for synthetic light gear oil or taking up some slack in the throttle cable but the thing hauls noticably quicker. The tranny is really quiet now and I can coast about 10 times as far. Acceration is quicker and the sound is quite different. I used Silkolene light gear oil for offroad application.

[florida derbi rocket]

I'm Glad you discovered the Throttle cable trick...It would probably solve most of the "Lag"...and "carb stumble" problems around here..If there is slack in my cable I'm probably dumping a bunch of gas all of a sudden into the Cylinder...and of course it takes a mili second to catch up...YEA!! Gotta LOVE 2-Strokes...I do!!.....BTW?? did you say Silkolene comes in 75-90?...I gotta change out my 30 weight..Soon

[t-bone]

They offer just about everything. I used their offroad light gear oil in 75 80. I use it in my CR so I just had some. They do make a scooter specific stuff too though.

[lunar_luna]

How to tell if throttle cable has slack? Is it tightened at the grip or at the carb?

Thanks!

[florida derbi rocket]

I just see if my throttle grip is loose..if there is twist play..you just screw out the cable adjuster by the grip.....till there is no play......you can feel if you're pulling the carb spring..thats all you wan't to feel from 0 To wide open throttle....Spring tension.....there is usually a lock ring on most throttles.

[t-bone]

Technically you want 3-5mm of play per the service manual. :)

[florida derbi rocket]

I guess it's a personal preference thing....I also tilt my throttle forward on the bar ..so my wrist is straight at WOT.

[Charger92]

....I also tilt my throttle forward on the bar ..so my wrist is straight at WOT.
Why would you have to do that. The throttle cable will be the same length where ever the twister is positioned. If you gab the twist thottle at a more upright position and twist till full throttle your wrist will be straight. If you grab it at a straight postion then twist your wrist will be angled. So it depends on where you grab the twist throttle you can acheive different wrist positions, Not where the twister is located. Your still traveling the same cable length for WOT.

[florida derbi rocket]

I have a Derbi Atlantis (piaggio) scooter with a dellorto carb...I must have more twist than a Zuma...what you're saying about grabbing the throttle at a more upright position doesn't work with me..I am constantly re-positioning my hand...I also live in a Historic district....I don't have Long curving country roads..this means start...and stop..constantly..its the payback for living in Victorian 2 story homes.

[florida derbi rocket]

also..what I meant about "play" wasn't the twist...I'm talkin' Slack...slop...I don't know why Yammy would wan't you to have a loose cable..(per the service manual??)......doesn't make sense....

[cripplediguana]

You are saying to check for cable slack just twist the grip and feel for tension? I think mine is a little loose, but only the 2-3mm that the service manual suggests anyhow.
Think it would make much difference to make it more snug?

Thanks,
Kyle.

[speedy_scooter]

ya never know until you try. take up the slack and test it, if you dont like the results put it back to the old way.

[Iceman]

I brought up this question quite a while back about the slack on my 2005 Zuma. I tried to adjust it but was afraid to go to far since the factory cable seemed to not have enough adjustment. After reading this thread today I decided to recheck mine and closed the play down to minimum (probably within the 3 mm range). Yamaha uses the dual cable set up and I feel this is a poor design on a good scooter but anyway after I adjusted the cable there was a world of difference in the acceleration response on the Zuma. Good call. I also adjusted the cable on my Vento but have not had a chance to try it out yet. I hope I can see as good of a response on it as on the Zuma. I'll post my results if any after tomorrow. I can't believe I waited so long to find this out. :dunce: _-_-_-

[speedy_scooter]

on which end did you take up the slack on the vento on the throttle or at the carb? i have been thinking about doing this but dont know which one i should adjust it at. thanks!

[Iceman]

on which end did you take up the slack on the vento on the throttle or at the carb? i have been thinking about doing this but dont know which one i should adjust it at. thanks!
The Vento didn't have near as much slack as the Zuma so just a little turning at the throttle end seem to do it. I will be taking it out shortly for a test ride and see if and how much it helps. I am really not looking for as much change as the Zuma because of the low end differences in the two bikes.

::handleba

[Madcat]

I have a 05 Zuma. Switching to pure synthetic really made that much of a difference? I'm thinking about just changing it out. Are you sure that's what made the diffference?

[t-bone]

It was certainly the fluid that allowed free coasting and quiet gears. Its a lot thinner than what came out.

[speedy_scooter]

i checked my throttle and there wasnt anymore to tighten. i guess i just got lucky and when i installed my carb it was right. its one of those things you never think about, at least i never thought about.

[ScooterJim]

Yamaha wants slack to ensure that there is not any tension causing a high idle due to temp changes and manufacturing differences.

Especially after grabbing a handfull of throttle there is some slight stretch to the cable, and yeah buddy a slack adjuster solves the issue...

Now... about that hand position thing... Let me see here... the grip is ROUND... so positioning the throttle in a more down position would have no bearing on the matter (or am I missing something here?) My wrist moves freely, and yes, I reposition my hand for long WOT rides. Unless you go to a 'short throw' twist grip (made popular by Huskies in the 70's) you are always going to have more 'twist' that wrist.

Moving the trottle for less twist.... entertaining at the least (I moved mine down to lower the brake lever, and the throttle still has the same amount of 'rotational' leverage).

[florida derbi rocket]

Yea..I already got beat up on this one..Everone brain farts once in a while..I have some fused bones in my right wrist from falling 30' onto bricks....Gets irritated when my wrist is straight..and hand is pointed up at WOT....I might look at other throttles..

[larry-new]

Yea..I already got beat up on this one..Everone brain farts once in a while..I have some fused bones in my right wrist from falling 30' onto bricks....Gets irritated when my wrist is straight..and hand is pointed up at WOT....I might look at other throttles..

Look for the tab ($10) that attaches to the throttle as a cruise control...they are adjustable and take the pressure off the wrist, while allowing a looser grip.

...and as for the oil thing, the placebo effect is alive and well...(see the thread on removing the plug washer).

One of man's greatest talents, unfortunately, is the capacity for self deception.

Larry [ shiftless . ]