Tuning advice - 2020 ruckus 1100 miles

2020 ruckus that I purchased new in July and it now has 1100 miles and has ran fine.

Current mods are, Ncy Cdi, Ncy coil, ngk 10 iridium plug, polini variator and a constant mix of 4.5, 5 and 5.5g dr.pulley sliders, yoshimura exhaust, TRS TVR intake, 38/78 jets that were included with the intake, I have not yet installed the needle shim that came with the intake kit as I had read a considerable amount of info saying it’s for covering up bad jetting.

Before the intake and exhaust I had a mix of 4m5 and 5g sliders and would turn 49mph at 10400 downhill. Flat ground was 40-42 depending on the weather and if it was actually flat.

After intake and exhaust and jets it felt better and would easily do 42-44 on flats and still rev out to 10400 at 49.

Tonight I swapped to 5.5g sliders and I feel like it’s a mega turd. I ran the velocity stack in and out about 1/4” each way and made passes and it felt better just a hair out from the 1.5" that it came to me at.

I’m at 700-900ft elevation, DA is usually in the 2500-3500 range. I’m not tucking during these tests to keep things the same. Stock tires and pressure is at 30 front and rear.

I currently need to redo the tach lead as it freaks out and shows about half the revs once it breaks 6400 under load but it’s audibly lower in the revs and not trying to pull thru them as I expected it to after intake exhaust and rejet.

Do I have a hodgepodge combo that just doesn’t work? How would you proceed?!

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Did you add all the extra components yourself? It is best practice not to change or add too many performance mods at a time.

With a 2020 Ruckus you will not need the shim.
Are you using the TRS TVR intake as it is sold or have you shortened the runner? If you are using the intake just as they sell it like this:


you will most like have better luck with a larger main jet like a 80 or even an 82. You should try both and record your results.

Also when tuning set your goal RPM to be no more than 9600. Try to get up to 8000 as fast as possible and stay between 8000 and 9600 for as long as possible. If you don’t wight more than 220lbs, you should be able to hit 48 to 50 mph on flats without going over 9600.

Long story short a lot of tuning is just testing and experimenting with different combinations.

Here is a link to the tuning journal that I use.

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Yup it’s the length it was out of the box. Shouldn’t I just be able to push the velocity stack in and accomplish the same thing?

Why wouldn’t I need the shim? I was under the impression that all of the carbs were the same and other than pcv system all the same

The best length for the runner and stack is much shorter than the TVR runner, you won’t be able to shove the stack in far enough. Basically you want the to cut the rubber 90° coupler down to only be a 45° coupler and then have the total length stack and runner be about 4.75 to 5.25 inches total. At this length you won’t be able to use the supplied stack mount but you shouldn’t need it. Also at the shorter length the system will be more efficient and the 78 main will work better. Right now you are most likely running lean.

As for the shim. In 2006 Honda changed the needle shape and this fixed the midrange bog. The shim was used on the pre '06 to fix the bog, but your 2020 has the correct shapped needle.

Part throttle it breaks up. cleans up just fine at wot. Before the intake and rejet it would pop under deck fairly bad. All the way out and all the way in I never had any of that. The exahaut note did seem to mellow out a good bit when the stack was all the way in.

Any suggestions on where to get a 45 hose?

You can use this one, or just do an eBay search for a 1.5 id 45 degree silicone coupler. You will want to cut down the arms on both side to you have just the 45°.

45° coupler from Amazon

I just cut the supplied tube down to about 5" which was about the middle of the 90 bend. It seems considerably happier now. I will say, the tone is less desirable now tho.

Man, thanks for the journal. I’m laughing at myself looking at the two lines you filled in. I resemble that–too much at once–but I’ll get it dialed in eventually.

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