The Honda PCX / Forza / ADV150 / SH Forums

Kitaco and Yuminashi (maybe others) make gear up kits for the PCX's transmission to change the final drive gearing.

The transmission is a bit of a hassle to get to. It involves removing the exhaust, rear wheel, and the entire drive assembly (variator and clutch). Additionally, the Yuminashi kit involves pressing off a gear and pressing a new gear on, which required (at least for my PCX) a huge industrial press. The Kitaco kit is just replacement of one gear though, which is trivial.

The only downside to either kit is, the speedometer does not account for them. The speedometer reads off the Final Gear (as Honda calls it), which is completely confusing given the clutch shaft outputs to the Drive Shaft, and the entire microfiche provided by Honda is rotated 180 degrees from how you see it on the bike.... It gets confusing, so here's a quick primer on the PCX transmission before I start:
Quick disclaimer: This all is stock on the 2011 PCX. Other PCXes may have *slight* variations in gearing.

5. "Drive Shaft" according to Honda. 17 tooth stock. This interfaces with the clutch, and sticks out the left side of the transmission into the clutch. Interfaces with 7. No aftermarket options exist that I know of.
6. "Countershaft" according to Honda. 13 tooth stock. This is driven by 7 (which it slides into), and outputs to 8.
7. "Counter Gear" according to Honda. 53 tooth stock. This is driven by 5, and outputs to 7 (which slides into it).
8. "Final Gear" according to Honda. 47 tooth stock. This is driven by 6, and outputs to the rear wheel.

About the Kits

• The Kitaco kit (Kitaco 305-1426010) replaces the Counter Gear, switching from a 53 tooth gear to a 51 tooth. The new gear interfaces with the stock 17 tooth Drive Shaft. The stock ratio is 3.12:1, and the new ratio is 3:1, or a 4% increase in top speed.
• The Yuminashi kit (FORGED GEAR SPROCKET SET 15/45 (3.0)) changes the gearing on the PCX from a 47 tooth Final Gear interfacing with a 13 tooth Countershaft to a 45 tooth Final Gear interfacing with a 15 tooth Countershaft. The stock ratio is 3.62:1, and the new ratio is 3:1, or a 20.67% increase in top speed.
• Gearing is multiplicative, meaning these changes together add 25.5% overall increase in top speed. For a nominal speed of 65mph actual, that means 81.575mph new actual speed, assuming your bike can push down the power to get there.
• This also means that 81.575mph new actual speed will read as 65mph with the stock speedometer. You can fix that with a speedometer healer, which I might buy and make a howto for eventually.

That all make sense? Good! My Kitaco kit is in from long ago, so I don't have the packaging, but here's the Yuminashi one. Note the new speedo sensor:
Start by removing the rear wheel, as in this how-to: http://hondapcx.org/viewtopic.php?f=3&t=1356

Next, remove the lower left body panel and then the CVT cover, and then the variator as in this how-to: http://hondapcx.org/viewtopic.php?f=3&t=2598

Next, remove the clutch. You can use the tool and a wrench the same as the CVT, but almost all PCXes will require an impact gun to remove the clutch the first time, as a fair warning.

I don't run with a centerstand, so my PCX is sitting on a toolbox for a tile saw. You can just use a centerstand, no need to buy a tile saw for the case. Here's a pic where you should be at this point:

From that pic, it looks like I forgot to say undo the rear brake... Do that too.

Next, remove the speedometer cover. There's an allen wrench at the front and back:

The speedometer sensor is clipped to the cover, so wiggle the back to the right to get it off the grommet on the back right side of the cover, then lift, exposing the speedometer cable. Gently unclip it.

Finally, unclip the little wire retention clip for the speedometer sensor and pull the cover off.

Flop the rear drum brakes off. They just both flop off from the top towards the middle.

Pop off the breather hose. It goes into the airbox and is just tucked up in there.

Drain the oil in the final drive through the drain bolt (the one that is missing in this picture). Remove the other 6 bolts that secure the transmission cover in place. Bolts before removal...

...and after:

The bolt lengths vary, and their location is important, so I have laid them out in the same layout as the holes:

Slide off the transmission cover.

Here's our gears! Notice how it's rotated 180 degrees from the Honda Microfiche... Silly engineers. The Final Gear is on the left, the Counter Gear is in the middle, and the Drive Shaft is on the right. Remember, those are Honda terms, not mine.

The Kitaco kit replaces the center gear. The Yuminashi kit replaces the left gear (you have to use a press to get it off, then back on the shaft) and the gear hidden behind the center gear.

The center (Counter Gear) should pull out by hand.

Here's them side by side. Hell if I remember which is which, I took these pictures months ago. You can count the teeth if you want. They're very similar in appearance. If you are doing the Kitaco kit, drop the new gear in and reassemble and you're done.

The Final Gear and the Countershaft also just comes out by hand.

Old Countershaft on left, new on right.

In this pic, I've already had the new (smaller) Final Gear pressed onto the driveshaft. The bigger stock one is on the left, new on right.

Here's the Final Gear getting pressed on. The press is huge! Good thing we have a machine shop at work. You CANNOT remove and put back on the Final Gear for the Yuminashi kit by hand. Even the 12-ton shop press I bought from Harbor Freight couldn't do it. I ended up using the absolutely massive one at work, which is at least a 50-ton press. It's self-explanatory to press a gear on or off if you have a press, so I'll leave that to you.




The Final Gear before going in:

The gearbox, sans-gears:

Adding them in:

And ready for the cover with the new gasket in place:

Reverse the process to put it all back together, add 10w30 as your gear oil (yes, that is what Honda calls for as the specification) and you're done. If you need instructions for filling the final drive oil, see this thread: http://www.hondapcx.org/viewtopic.php?f=3&t=3224


The speedometer sensor can be replaced if you bought one from Yuminashi. The stock one won't read off the smaller gear. It's a quick swap while you have everything apart. Remove the one bolt securing the sensor:

Old sensor on right, new sensor on left. Notice how the new one is longer.

Pull the oring off the old sensor gently. The new sensor does not include an oring, so you can reuse the old one:

Install the new sensor and reassemble. Again, please make sure to fill the transmission with fluid.


I hope you found this how-to helpful. If you have any questions or get stuck along the way, feel free to ask.

Thanks Maddiedog - another excellent how-to. Not going to do this but always interested in such things Wow, just noticed how many bikes you've owned or own - I make it 18!

Thanks, Iceman! Glad you enjoyed it.

Nice how to maddie. I'm sure it's somewhere there on the site but what is different with 150 gearing vs 125 and what' percentage is the diff in gearing between the two?

Cheers

On the PCX 150, the Final Gear is 44 tooth. On the 2011 (PCX 125), the Final Gear is 47 tooth.

The parts are not directly interchangable, but you can likely (unconfirmed) replace the Final Gear and Countershaft as a unit (the Counter Gear has the same part number).

On the Transmission microfiche from Honda, the part numbers for the 2011 are: 23430-KWN-900 (GEAR, FINAL (47T)) and 23421-KWN-900 (COUNTERSHAFT (13T)) versus the 2013+ having the part number
23430-KZR-600 (GEAR, FINAL (44T)) and 23421-KZR-600 (COUNTERSHAFT (13T)).

This is also why stock 125s often top out at 55 (before an aftermarket vario), while stock 150s will climb up to 65 or so indicated.

Very professional and inspiring how-to
Well done

Nice upper echelon PCX skills... good job boss

hello what gear set ratio to be used on my version 2 honda pcx 150i 2018 model to increase top speed. thank you

maddiedog is Kitaco kit worth it.

hello good morning guys. I changed a number of times the gear wheels to get to where I wanted to speed, at this moment I have assembled a yuminashi kit I don't remember the original value, (for what I have pointed out here) the first kit was 15-51- 45, then I rode 13-51-44 and lastly and what I have now mounted 13-53-44 .. I can go to 145/150 kh on the highway

I know this is an old post but I want to try my luck as there is not much information available on this subject. I have a 2016 PCX and I bought a 170CC bore kit. I ordered the Kitaco but I am confused about which Yuminashi to order as there are so many different ones... I just want the bike to run at a decent top speed and for it not to have that moped feeling (If that makes sense) when driving at 60 miles an hour. The other 2 questions I've got are you said that the speedo will be off but the Yuminashi comes with a speedo does that mean that it will be accurate or is this again something extra I have to order (In this endless money pit ) and my last question the one that concerns me is you said I need a press to get the gear off? What sort of press? r are there any other ways? Hope to get a reply on this so I can crack on ordering and modifying... Cheers in advance

Pat

Hi Maddiedog

It has been many years since you did this. I have purchased the new gears to do it to my 2015. (The Yuminashi kit (FORGED GEAR SPROCKET SET 15/45 )(3.0))
Did you find that the results were worth the effort and expense?

Thanks

oldgoat

Hello good day . How can I see the value of the relationship for example this 3.0 how do you do the math to reach this value?

Scroll up on this thread to the parts breakdown picture from Honda. No. 6 the countershaft gear turns No.8 the Final drive gear. Now simply divide the gear teeth to get the ratio. 45 tooth gear divided by 15 tooth gear gives you the final drive of 3.00 ratio. The 15 tooth gear turns three times to turn the 45 tooth gear one time, and that is another way to see the 3:1 ratio or 3.00 rear end gear ratio. Just like a regular car the rear axle gear ratio is the final drive ratio. The stock gear 47 / 13 gives a ratio of 3.61, which gives more low end torque and better off the line acceleration but a lower top end speed. The stock gear 47/13 gave me 58mph with no modifications. The 45/15 with the Yuminashi 164cc big bore kit with new cam shaft and 34mm throttle body and 13 gram rollers gave me 72mph top end speed. On the center stand the top end speed was 80mph, but there is not enough horse power to reach that while I am riding it. I weigh 190lbs and have a givi mid height wind screen and a givi top box mounted on the rear. This winter I am going to replace the stock exhaust to a larger pipe and larger muffler. This should gain enough horsepower to maintain the 70mph speed I drive and not have to be wide open throttle.

thanks for the quick response. now I realized...and the smaller the number the higher the final speed...this of course if the engine holds up...thanks

I have finished installing the Yuminashi 45/15 gear set. I was surprised to find that the oem final gear was 44T. Mine is a 2015 model. I then looked in the parts fiche and that is what it is supposed to be.
I should have checked the parts fiche before I bought the replacement gears. Stupido!!

So I will now have a 3.0 final gear ratio, up from a 3.38 ratio (44/13)

I f the engine has the power, I will see an increase of 12 or 13% in top speed. This should meet my needs.

Winter has arrived in Montreal so I can't check it out on the road until April at the earliest, Grr. I have also fitted a Garmin GPS and a SpeedoHealer so we'll see what is what then.

Is your PCX stock other than the 45/15 gear set ? It will be interesting to see what top speed you are able to get. I have two PCX's , mine that is modified and the wife is bone stock. Please post when you get results. I would be interested to see how a stock bike performs with the gears.

Was stock until I swopped out gears.

Update
Max now 112kph, 70mph by GPS The Speedohealer now has the scooter speedo reading the same as the GPS.
It no longer bounces off the speed limiter at maximum speed as it used to.

I'm happy with it as I can now keep up with the traffic as I exit Montreal island on the autoroutes (interstates). I then go onto country roads for slower, pleasant rides.

Hello! is this guide accurate for the current generation PCX? will it also work with the 2022 Honda PCX 157cc 4 valve engine?

I consider myself moderately inclined, mechanically speaking. I wouldn't consider myself "engineer" so gear ratio arithmetic is out of the question.

I can however take pictures and document step by step procedure when the time comes.
Also I didn't see the yuminashi kit part number. I would love for my 2022 PCX to do 81MPH

EDIT: P.S is the pcx 150 parts basically compatible with the 160cc PCX? Thanks in advance.