Main Jet question, weird topped out sound

[thebadfish]

Hello all first time poster,

I recently bought a Dr.D exhaust for my 08 Ruckus and after doing some reading went about re-jetting my carb. I have found that the 85 is by far the best so far but after reaching 3/4 throttle or around 36mph the Ruckus sounds as if its hitting a rev limiter and loses all sound from the exhaust and wont go any faster. After this i tried going higher on the main jet and that didnt help at all either. I am also using a KNM air filter and was wondering if oiling it might help on the airflow becuase maybe it is too much for the mix. I have not messed with the Idle mixture screw at all but had read that can help on some things. Any insight on this problem would be greatly appreciated. Thanks in advance, The Badfish

[Kami no Chiizu]

I think Chano would wag his finger at you for not adjusting the idle mixture screw first. But I'm no jetting expert.

[chanito]

YOU NEED TO ADJUST THE MIXTURE "BEFORE" ANY JETTING
Sorry for shouting, but this is a common mistake and it should not. if adjusting the mixture require more than one turn, then start messing with the jets, but not before

[jjavetz]

Chanito-

Any advice for the following set-up...I dont really feel like f-ing things up on the first try. Just bought an 08 Ruckus and the following fun partd:

Polini Variator, Belt and Exhaust
Blue Clutch Springs
Main Jet kit
CDI no limit
A-Bomb extension kit

I am 250lbs (i know, lose weight...ok, I will)

What weights should I start with on the Polini?
what should I expect with no tuning after installing what I bought?
Is the extension kit easy to install?

thanks for any help you can offer. ;D

[chanito]

At our weight, the Metro weights (6gr) give you better accel, but will lose some top end, i went back to the original weights (7.5gr) so i could keep my top speed

[evilkaneval]

Aug 11, 2008 18:15:01 GMT -5 chanito said:

YOU NEED TO ADJUST THE MIXTURE "BEFORE" ANY JETTING
Sorry for shouting, but this is a common mistake and it should not. if adjusting the mixture require more than one turn, then start messing with the jets, but not before

Chanito, Do you mean this to apply to just the slow jet, or main jetting?
'Cause I thought the mixture screw only made adjustment to the slow jet?
Will adjusting the mix screw have affect on top end?

[chanito]

:(0 This is sad i went thru all the trouble to explain jetting on a stock carburator, the idle system works ALLTHE TIME, is just that as the throttle opens the % of the fuel it contributes to the mix goes down, but is VERY IMPORTANT on all part throttle mixtures and on acceleration, Main jetting should only be adjusted for full on throttle, which we do a lot, but for any modification do idle mixture until the byke rides and starts good then knock yourself out by using a main jet that give you the best top speed

[evilkaneval]

Okay got it.

Oh, and don't be sad. I just wasn't tottally sure. We all appreciate the trouble you've gone through to disect and explain all the mechanics of the Ruckus.

[itznam1731]

So let me get this straight:

If my 09 ruckus once did 40 stock but since has drop down to 37-38 top speed (rev limiter kicks in) it's just becuase i replaced my drop in filter and exhaust and i simply need to make an adjustment to the stock carb?

[chanito]

More than likely "YES"

[scooterbill]

thebadfish. You need to lightly oil your filter.