PGM-FI Controller for first generation PCX150 (KF12)

[Oyabun]

I'll get my hands on the Torque Control vario this morning. I'll take detailed photos for you guys.

Highly appreciated.

[Pcxdemon]

Can I just say how much I love this current set up? It's a beast, midrange power is just fenomenal! I'm certain that from 80-100kmh is in about 3sec quick..just surprises me every time I fang it for a quick bursts..

[BPT7594]

Would have to content myself with the stock Head now. Hearing you said that makes me so curious.
Maybe I can reused my ported head with 29 23 valves, who knows?
please check my other post. The build post. Got some goodies today.

[Oyabun]

Can I just say how much I love this current set up? It's a beast, midrange power is just fenomenal! I'm certain that from 80-100kmh is in about 3sec quick..just surprises me every time I fang it for a quick bursts..

We definitely need a video of it. :-)

[BPT7594]

Hey guys.
I installed my BBK today. However there's a problem. The yuminashi 31mm throttle body do not have an idle adjusting screw (For my scooter, PCXs are fine I guess).
And also there's a solenoid and valve setup on top of my stock throttle body. like in this image.

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number 9 and 10.
It's a solenoid valve, I think it's adjusting the idle in some sort, or just adjusting the amount of air getting into the engine when the scooter is not in idle.
However, on the Yuminashi throttle body and based on their image, they do not install this solenoid valve into the 31mm throttle body and just leave it there.

I tried to start the scooter expecting flashing check engine light but NO. Nothing happens, the scooter starts easily, with an unplugged solenoid valve. I figure it's not a sensor so it's bypassed?
Can I install my stock solenoid valve on the Yuminashi throttle? I did not check it but it might fit, but again still no adjustment screw?

[Oyabun]

Hey guys.
I installed my BBK today. However there's a problem. The yuminashi 31mm throttle body do not have an idle adjusting screw (For my scooter, PCXs are fine I guess).
And also there's a solenoid and valve setup on top of my stock throttle body. like in this image.

number 9 and 10.
It's a solenoid valve, I think it's adjusting the idle in some sort, or just adjusting the amount of air getting into the engine when the scooter is not in idle.
However, on the Yuminashi throttle body and based on their image, they do not install this solenoid valve into the 31mm throttle body and just leave it there.

I tried to start the scooter expecting flashing check engine light but NO. Nothing happens, the scooter starts easily, with an unplugged solenoid valve. I figure it's not a sensor so it's bypassed?
Can I install my stock solenoid valve on the Yuminashi throttle? I did not check it but it might fit, but again still no adjustment screw?

That is the IACV (idle air control valve). It is automatically adjusts Idle air and this is the reason why there is no manual idle screw on the throttle body.

[BPT7594]

My stock throttle body an air adjustment screw. My scooter is a click 125i, it does not have IACV but only a solenoid valve? I think they're the same but don't know why on the pcx it's fully automatic and called IACV but on our scooter it's just named "solenoid valve" and we have an idle air screw? Really not understanding what the solenoid is doing on my scooter ?
The idle air screw on my stock throttle body is part number 1 in the above mentioned picture.

[Pcxdemon]

From my expirience, Yuminashi tb comes with no pre installed sensors, you need to take them off you stock tb and install them back on 31mm..

[Oyabun]

As neither the air blade nor the click is sold here I only have a humble engineering guess about the reasons.
My base assumption is that the PCX is a global model, while the earlier two aremade for the asian market.
Based on the above assumption the PCX has to operate in much more diverse situations ( e.g. where I live it is fairly common to have 38-39 degC during summer and today morning it was -2degC when I rode off) and our markets are a bit less price sensitive too.
At the same time Asian markets are very price sensitive but moving huge volumes of sales so -saving 10 Usd time millions equals in a healthy sum - and weatger is a lot more even with less of a "real winter" enabling use of a simple valve (practically an electronic choke) instead of a stepper motor on the intake.

As I said I have no clue if the above is the real driver- but it makes sense to me.

[BPT7594]

Thank you for your suggestions.
I made the 31mm TB work for my scooter, with one weird trick given to me by Reggy himself (really).
My idle is comfortable at 1800 rpm. Idling stop works like a dream. I use a stock camshaft so starting and using Idling stop is fine.
Great power. Even without the camshaft. Next time I get my hands on my new cam I'll see if I can slap a 150 esp head on there.

[Oyabun]

Thank you for your suggestions.
I made the 31mm TB work for my scooter, with one weird trick given to me by Reggy himself (really).
My idle is comfortable at 1800 rpm. Idling stop works like a dream. I use a stock camshaft so starting and using Idling stop is fine.
Great power. Even without the camshaft. Next time I get my hands on my new cam I'll see if I can slap a 150 esp head on there.

Good to hear that you like the results. Can you possibly share the trick with us?

[BPT7594]

Thank you for your suggestions.
I made the 31mm TB work for my scooter, with one weird trick given to me by Reggy himself (really).
My idle is comfortable at 1800 rpm. Idling stop works like a dream. I use a stock camshaft so starting and using Idling stop is fine.
Great power. Even without the camshaft. Next time I get my hands on my new cam I'll see if I can slap a 150 esp head on there.

Good to hear that you like the results. Can you possibly share the trick with us?

Of course.
On the Yuminashi 31 TB there will be an IACV sensor, which is the black thing on the back. If you guys run a PCX, there will be no hassle I guess, install your old sensors on it and boom work like a dream.
My scooter does not have an IACV sensor but a simple solenoid valve and a manual idle air adjustment screw, manual as in carburetor style manual.
This is how Reggy told me to do it. remove the IACV from his TB. In theory, the IACV works by electric, pushing the piston inside in and out to close/open the air inflow which bypass the throttle plate to help the engine idle. But the IACV piston can also be turned by hand inside or outside, as a measure to remove it and fix it if it runs into problem. So I remove it and turn it counterclockwise 3 times, insert it in, because the piston has a ramp to be fixed into a copper thing inside the TB, it does not change its position. and since there's no electric applied to it, it'll stay that way forever and help my idle to be stable at 1800 rpm.
I really had a good laugh and complimented Reggy for turning something that is supposed to be electronically controlled into a simple idle air adjustment screw. In my book that's street smart at its best.
My engine revs happy now. This is the feeling I've longed for since I started tuning. When I install the new Yumi cam, I'll see if I can fit 29/23 valves to make the engine breaths easier too.

[nedla]

thanks BPT, do we have the same stock throttle body?

[BPT7594]

thanks BPT, do we have the same stock throttle body?

It's the same. If you order Yuminashi throttle body and A type manifold you'll have no problem. I can show you how to install it very easily.
However I see your scooter has dual throttle cable. Yuminashi is single cable. You'll have to drop one cable then. To me it's not a problem.

[nedla]

ok noted Pham..

[BPT7594]

Would have to content myself with the stock Head now. Hearing you said that makes me so curious.
Maybe I can reused my ported head with 29 23 valves, who knows?
please check my other post. The build post. Got some goodies today.

Please have a video of it haha.
And do you happen to know if the ECT sensor of a 125 esp is compatible with a 150 esp head. I really want to try bigger valves when Reggy confirmed that running his 60mm kit with bigger valves and high lift camshaft is absolutely fine.. and with your results I'm really excited..

[BPT7594]

I just found out today that a PCX150 head and a SH150 head differs in the ECT sensor, painful price to pay though, I had to resell the SH150 head and wait for my PCX150 1st gen head to arrive from Thailand.
I spoke with Reggy the other day, he had this for us. New piston with higher dome for more compression, this is for the guys who wants to run the PCX150 head with bigger valves since the combustion chamber from that cylinder head is bigger, therefore less compression..
He also talked about a flat deck cylinder, which I think he meant for better protection against gasket leaks..
Here are the pictures he sent me yesterday.

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[Oyabun]

The new kit looks really sexy. The full top sleeve is usually used in high power engine applications - helps to control cylinder sleeve vibration and distortion under load, and also provides better cyl head sealing and more resistance against the issues caused by the different heat extension of steel and aluminium composite materials.

[BPT7594]

The new kit looks really sexy. The full top sleeve is usually used in high power engine applications - helps to control cylinder sleeve vibration and distortion under load, and also provides better cyl head sealing and more resistance against the issues caused by the different heat extension of steel and aluminium composite materials.

The price is steep though. And the compression from this kit when used with a pcx150 head is even higher than a flat top piston (more than 12.. Reggy really pushes everything closer to the edge this time.
I know he tries to be as safe as possible but I'm still scared of running too high compression

[Oyabun]

High compression is good if operated properly.
The thermal efficiency of an Otto cycle internal combustion engine is calculated the following way:

1 - 1/(r^(γ-1)),

Where r is the compression ratio, and γ is the specific heat ratio of the gas in the combustion chamber. By not really being able to change the specific heat ratio efficiency can be increased by increasing CR.

(For those other nerdy ones like me - more detailed info for example at the following location from MIT: http://web.mit.edu/16.unified/www/SPRIN ... ode25.html)

The first generation Mazda Skyactive petrol engines operate at 14:1 CR while the Skyactive 2 has 18:1 compression ratio!

However higher CR engines are really dependent on good and consistent fueling and good quality fuel with high detonation prevention capabilites. Mazda claims that by lowering the CR to 13:1 their engines can be operated on regular fuel instead of premium.