Project Honda Ruckus part 3, 50 mph or bust!

By Jeff Naeyaert

When we last left Project Honda Ruckus in part 2, our first performance mods which included a Yoshimura pipe and a Bowls PC20 big bore carburetor kit had increased the top speed of our Ruckus from a pathetic 37 mph stock to a more reasonable 45 mph. However this was not fast enough to safely cruise on the fast streets of Orange County. The acceleration to reach this top speed was pretty lame as well. We had to get more speed, for safety and to be able to smoke the snobby Vespa riders in our area that would turn up their noses at our little Honda.

Honda Ruckus Posh CDI
The JDM Posh CDI box with high output coil raised our rev limit to 10,500 rpm while giving us a hotter spark and more aggressive advance curve to boot.  This easy to install part is essential to get the maximum out of the stock engine.

The first limit to our top speed was twofold; we were running out of gear and hitting our rev limiter. Our acceleration was hampered by several issues as well. We decided to address our top speed first. Bowls came to our aid by supplying us with a Posh CDI unit and coil. This ignition system not only gave us a hotter spark but bumped up or rev limit from the stock 8900 rpm to a much more respectable 10,500 rpm. The Posh ignition box also has a slightly faster advance curve. We also installed a Denso iridium plug at that time. The ignition system installed easily in a few minutes and bumped up our top speed to around 46-47 mph as we were no longer on the rev limit.

Honda Ruckus big K&N air filter
We installed a bigger K&N filter with a dust shield to get better flow.  We had to up our main jet to an 80 to compensate for the increased air flow.

Next we gave our engine a little more airflow by switching to a larger K&N air filter, also from Bowls. The bigger K&N also had a chrome shield, good for protecting the air filter from splash and dust kicked up by the wheel. The bigger, lower restriction air filter leaned out the motor slightly and we found a little more power by going to a larger 80 main jet. We were now able to hit 47 mph more consistently. At this time we removed the stock AIV system, blocking it off and using one of the big crankcase hoses as a crank case breather, putting a small breather filter from Bowls on it. Although many argue that the AIV system is important for engine longevity, we believe that this is simply not true and as long as the crankcase is vented freely so pressure will not build up; there will be no long term issues with engine durabilty.

polini Honda ruckus variator, daytona rollers
The Polini variator has a larger diameter than stock yielding a higher top gear.  The yellow rollers in the case are the soft, quick wearing rollers that came with the variator.  We used the harder slicker and smoother, longer wearing brown and grey JDM Daytona rollers with better results.  The variator back plate is the black thing with the three notches in it.

With the rejetted carb and CDI, we had better power but we were revving past the power peak. To fix this, the next step in increasing our speed and acceleration was to add a Polini high performance variator also from Bowls. On a scooter the variator is part of the continually variable automatic transmission that controls the rate of upshifting. It is basically a pulley with internal ramps in which rollers sit that is bolted to the crankshaft. As the engine spins the variator faster and faster, centrifugal force causes the rollers to fling outward and roll up the ramps pushing on a solidly mounted plate called the back plate. Since the back plate can’t move, the pulley is forced by the rollers to move outwards which forces the drive belt to ride higher on the pulley, thus upshifting the transmission.

Read Part One Here!

Page 1 of 4 Next Page
Bookmark and Share
Sunday, October 11, 2009 11:53 AM
Do they have a class for these at bonnaville speed week? LOL
Tuesday, October 13, 2009 4:48 PM
Hey EJ25,
If you're going to make a snarky comment that proves what big and bad racer your really are, at least learn to spell Bonneville.

Ruckus' kickass!
Mike Kojima
Mike Kojimalink
Tuesday, October 13, 2009 6:41 PM
Be nice guys!
Wednesday, October 21, 2009 7:02 AM
Awesome build, guys! It'd be interesting to see the final tab on all the mods.
Tuesday, October 27, 2009 5:32 AM
I've been following the build closely and was wondering if anyone has thought of supercharging, they make small superchargers for karts, and I'm pretty sure a smog pump would provide enough pressure to have some serious fun. I'd read a build up of that and the engineering behind that over a list of bolt-ons any day
Mike Kojima
Mike Kojimalink
Thursday, October 29, 2009 9:19 AM
I know that people have supercharged the Honda Monkey with smog pumps with some success. We are not sure about the reliability without spending tons of money without engine management. If you have gone on some group rides with us, you know that a scooter can take some brutal pounding so reliability is important.

Our plans are to build the motor conventionally and for big power, our next project is going to be an engine swapped Ruckus with a GY6 which we will probably bore and stroke to 200cc and do our usual things for lots of speed.

We will also be doing a two stroke swap with a modded Yamaha Grand Axis in the near future.

MotoIQ will be getting into alternative modding more in the future.
Sunday, September 02, 2012 10:01 PM
Okay I own two Honda Ruckus's. there stock but one with stock OEM speed-o goes 44mph all day long the first one I got from Honda only goes 39mph? they look the same. There 2008 models! Making New Exhaust tonight. My work van got hit Friday 31st, and have to drive this fast to work on Tuesday 4th 2012.. Bikes only have 150 miles each. But I need it now... Porsche is in the shop! Jeep is getting painted... Just my luck...Weee!
joel Rodriguez
joel Rodriguezlink
Sunday, June 22, 2014 4:11 PM
I have a 2011 Honda Ruckus nps50 did a whole rebuilt engine port polish polish valves did the whole ten yards 20mm sheng way Big slide carb have a little problem with the valve shims its over 50 to choose from need your help
CarlosP 06
CarlosP 06link
Wednesday, March 11, 2015 6:28 AM
How much of a difference would I see if I were not to do a PC20 big bore carburetor kit?
Post Comment Login or register to post a comment.

MotoIQ Proudly Presents Our Partners:

© 2018 MotoIQ.com