PGM-FI Controller for first generation PCX150 (KF12)

[BPT7594]

I wish one day Vlad one day can come back.
He told me the other day that he planned on installing the 150esp head on his "angry chainsaw".
That leads to perhaps another big question. Because fitting a 150esp head with bigger valves is going to lower the compression ratio, not to mention if we have to machine the valve pockets a little or not, my take is it's going to affect overall power since CR and torque are directly related, so is power. Therefore, would it be completely necessary to do so if Vlad is not using his "angry chainsaw" at top speed all the time, since the bigger valves does not only results in a higher dome (lower CR) but also in the lower turbulence of air fuel mixture as it enters the combustion chamber? (of course we have to agree that AFM turbulence helps with better combustion).
Then another question, would it be much more cost effective for Honda to use the same 125esp cylinder head on their 150 engines like the SH150, PCX150 ETC.. because even a 60mm piston like Yuminashi or even Takegawa does not ask for a bigger valves, Takegawa does not even ask for a bigger throttle body or intake manifold or bigger injector. Then why would Honda do it? The SH150 has lower CR than a PCX 125, about 10.6 but is reliability really a concern for Honda?

[Pcxdemon]

Hi all!
Sorry,im still around but not as often though...We (my wife and i) bought a business and have been busy ever since. Working 100+hr weeks and although its not strenuous its just not much time left to play with the scooter. It still goes well,starts first time but it sits in the garage looking rather lonely..
Ive acquired 150 head while back and only now im slowly getting my self around to it to install it. It has preinstalled double valve springs,and ive taken it to the shop to polish exhaust port and bowl chamber for better flow. I was going to install it with yumi 164 kit as piston has 150 size valve cut outs but im changing my mind and might install the 170 from Takegawa instead. Although Takegawa uses triple layer head gasket and piston has 125 size valve cuts i think itll still be ok. Ive separated the gasket and the pieces look same as honda and yumi single layers so i see no reason i couldnt use it with some copper spray gasket for added benefit. Also what ive noticed with cylinder kits is that the piston never goes all the way to the top of the barrel but rather stop a good 2-3mm from the top before retracts so i see no danger where the valves may meet and interfere with flat head piston.Ill give it a go anyways and see how it goes...
Takegawa kit dyno graphs clearly show more power increase with esp kits between 125 and 150 in favour of bigger valves. coupled that with bigger cam,31mm tb, the gains should be a lot better than what they got...
Its interesting to note that esp engines use different exhaust manifold to the first gen 125 because of the new engine mounts.I figured that using the esp head in first gen 125 engine wont make any diff to my current exhaust setup as the exhaust port is in the same location as non esp 125 head so it should all align properly and simply bolt straight on...i hope!

Ill keep you posted how i go...

Cheers

[BPT7594]

I was going to install it with yumi 164 kit as piston has 150 size valve cut outs. never goes all the way to the top of the barrel but rather stop a good 2-3mm from the top before retracts so i see no danger where the valves may meet and interfere with flat head piston.

Welcome back.
Do you mean the Yuminashi piston that comes with their 164cc kit to use with the 125esp head has 150 valves pockets? (29mm/23mm) ??
Secondly, the piston of the Takegawa setup does not at least reach the top? with the circle at the top of the piston match the top of the cylinder sleeve ? I have never heard of that . If so installing a 150esp head won't be a problem really, but be careful anyway because I think the Yuminashi cam is way more aggressive than the Takegawa one

[Oyabun]

.............
Also what ive noticed with cylinder kits is that the piston never goes all the way to the top of the barrel but rather stop a good 2-3mm from the top before retracts so i see no danger where the valves may meet and interfere with flat head piston.Ill give it a go anyways and see how it goes...
Takegawa kit dyno graphs clearly show more power increase with esp kits between 125 and 150 in favour of bigger valves. coupled that with bigger cam,31mm tb, the gains should be a lot better than what they got...
Its interesting to note that esp engines use different exhaust manifold to the first gen 125 because of the new engine mounts.I figured that using the esp head in first gen 125 engine wont make any diff to my current exhaust setup as the exhaust port is in the same location as non esp 125 head so it should all align properly and simply bolt straight on...i hope!

Welcome back. Good to hear that all is fine with you.
Indeed the Takegawa has "only" 11.2 compression ratio compared to the 12.8 of Yuminashi even with a very similar piston dome setup. I gess that is why the Takegawa kit uses a dual base gasket to lower the CR of their kit to safe levels - and it might be also the case that they sport camshaft needs some extra clearance because it has a larger lift than stock.
Even though that raising CR increases volumetric efficiency - but the same time it increases the mechanical load on the parts and also becomes more sensitive to right fueling, ignition setup and increases the chance of knocking and more sensitive to fuel quality.
Good find with the 150 head. Hasn't looked into it so far, but it definitely seems to be the case. The 170cc takegawa kit without exhaust seems to pull the same peak Hp when installed on both the 125 and 150 engines (essentially only the head stays different). However the 125 seems to fall in power drastically above 80km/h (when the variator is locked out and revs start to climb above 8000). Installing the power silent exhaust not only gives +1 Hp on the 150 head, but also extends the usable power band even further.

All in all - the Takegawa with the large TB and the 150 head could be a safer to use kit it the fueling is right.
Curious to hear about the results.

[BPT7594]

The Yuminashi/APITech seems too good to be be true here.
3 areas of fuel adjusting.
Universal ignition angle adjusting.
All that with a narrowband O2 sensor and the chance the stock ECM will fight back to get control.
I'll try to get one and test the stability of it.

[dem0nk1d]

The Yuminashi/APITech seems too good to be be true here.
3 areas of fuel adjusting.
Universal ignition angle adjusting.
All that with a narrowband O2 sensor and the chance the stock ECM will fight back to get control.
I'll try to get one and test the stability of it.

the ECM / ECU will not take control as these piggy back systems, fake the signal input/output to work as nothing has changed.

[BPT7594]

The Yuminashi/APITech seems too good to be be true here.
3 areas of fuel adjusting.
Universal ignition angle adjusting.
All that with a narrowband O2 sensor and the chance the stock ECM will fight back to get control.
I'll try to get one and test the stability of it.

the ECM / ECU will not take control as these piggy back systems, fake the signal input/output to work as nothing has changed.

You mean the piggyback will have total control?

[iceman]

The Yuminashi/APITech seems too good to be be true here.
3 areas of fuel adjusting.
Universal ignition angle adjusting.
All that with a narrowband O2 sensor and the chance the stock ECM will fight back to get control.
I'll try to get one and test the stability of it.

the ECM / ECU will not take control as these piggy back systems, fake the signal input/output to work as nothing has changed.

You mean the piggyback will have total control?

Just wait till they fit all vehicles with AI then Skynet will be in control

[Oyabun]

The Yuminashi/APITech seems too good to be be true here.
3 areas of fuel adjusting.
Universal ignition angle adjusting.
All that with a narrowband O2 sensor and the chance the stock ECM will fight back to get control.
I'll try to get one and test the stability of it.

the ECM / ECU will not take control as these piggy back systems, fake the signal input/output to work as nothing has changed.

As a matter of fact, different piggyback work differently -as I wrote earlier.
Some are using brute force (intercepting ecu signals for ignition and injection and altering them) some are more subtle that they fake ecu inputs (TPS, O2 sensor, IAT) and some use a combination of both.
Just checked the APITECH instructions. It is the brute force version so no faked ecu signals. Therefore it does not allow changes on the closed loop portion of operation parameters.
It seems to have a quite sophisticated programing interface though - a lot more settings than expected or could be done through the dials on the face.
However my current uderstanding is that it will not cure your current idle and cruise lean condition. It has a simple afr data logger function also - so in case one installs a wideband sensor it will significantly help engine tuning. My best bet would be to install a wideband controller which has and adjustable simulated narrow band output (e.g. power commander wideband, or even better is the innovate motorsport wb2, etc.) which would enable a static shift in baseline AFR target from stoichiometric 14.7 to like 13.8 or 13.5. This would surely sacrifice some fuel economy, but would be a lot safer on a higher compression engine.

[Pcxdemon]

Head is installed! I've also installed takegawa 170 cylinder but with a single piece headgasket seperated a from the triple layer. Piston is clear of valves.. Exhaust doesn't match so 150 exhaust will be ordered and a temp sensor doesn't fit 150 head. 150 head is using smaller head sensor screw part so there are two options around it, one is to drill and tap new thread but since the head is installed I'm not taking it out again and other option is just to buy 150 sensor and use my koso temp reader connectors that have 150 plugs that I had to hard wire on to the earlier set up. The gauge came with piggy loop connections so it'll be easy to make it work..

[Oyabun]

Cool. Keep us posted.
Do you have pictures of the head porting by any chance?
Have you kept the Yuminashi cam , or using the takegawa one? Any estimation on the CR you are expecting?
can you please make measurements of the removed Yuminashi piston 's pin to crown distance? I have bought a spare 60mm piston but it seems a bit too high to me.
Hope the rest of the install will go easier.

[BPT7594]

Doing a conversion from the original PCX head to esp head sounds painful.
Hope you find a solution fast because I can't wait to hear about the results.
IMHO the CR is obviously lower than the previous setup. I think about stock 11? Since the 150 esp head drop it a little and the Takegawa setup is itself pretty low.
Oyabun do you know anyone who can ship the Forza head? I just got a little extra, so much I'm seriously giving it a thought. 2 things worry me though. The head will fit, if it comes with water temp sensor etc.
1/ the ECU? I have the Yuminashi 31mm throttle body and manifold now but I think a 4 valve setup is way too different from a 2 valve one that I'll run into serious issues.
2/ the piston? I have ordered the 60mm cylinder from Yuminashi now. But I don't think I'll be able to find a custom fit piston without going into too much details with a supplier. Hispeedpiston makes great pistons from Thailand but how can I describe my setup for them?

[Pcxdemon]

Sorry, I took no pictures...my phone has no spare memory and we were working fast to get it finished asap..
I retained yumi cam and stock 125 head roller rockers. I think the compression won't be too far of the 125 head as I'm using slightly bigger 61mm piston and only a single layer gasket with takegawa cylinder. I think it's the best possible set up and as close as I can get to the esp 175cc cylinder kits avalible for esp motors. Also I've been playing with the old exhaust. I can get it to work with only minor modding. Need to cut of the flange off, bolt it on to the motor and weld it back up, should line up quite easy. Atm the head exhaust bolts are slightly offset and don't line up with the old set up but it's easy to rectify.

[Oyabun]

Do you know the head gasket thickness what you have left out?
I have checked the product details for the Takegawa 170 kit and found that it has a 11.2 compression ratio with a 150 head. I assumed that the gasket which you did not install is 0.7mm and found that the staticc CR for this setup goes up to 12.9 - so very close to the yuminashi kit which is running 12.8. Drop of 0.3mm would give 11.9CR, 0.5mm 12.5)
Are you using the new copper gasket from Yumi, or the stock pcx150 gasket?

[Oyabun]

The best price I've found online is bike-parts-honda.com - it seems to be painfully expensive though. As I understand one has to order cylinder head assembly, valve train, and valve cover and gaskets. Shipping and possible customs add up to this. I believe there could be better ways to spend that amount of money and get better bang for the buck.
I myself at least waiting for the first totalled forza 125 bikes on the second hand market and planning to buy one for spares.
At this point I think BBC WITH properly sized injector, 150 head with cam, larger TB, a more free flowing exhaust, and a good variator is the best bang for the buck. All these (if the exhaust is not too expensive) could be bought for the price+shipping+customs of the 4V head.

[BPT7594]

Yeah it's just a crazy idea.
I have everything I need for my engine rebuild now.
Only missing some connectors and wire loom from Yuminashi, I found a guy who bought a complete set from Yuminashi and then sell his bike with only 6000km on the set, so saved some serious money there.
1/ 31mm Throttle body
2/ 31mm A type manifold
3/ CBR150 fuel injector
4/ B to A type wire loom
5/ 5 pin to 3 pin wire loom
6/ full Sonic valve spring set
7/ Cylinder kit from Yuminashi
I put out the Yuminashi cam btw, this guy has it too but it has some holes on the surface, does not look too good, I'll see if a stock cam can work well with this setup. I'll have my new 125 head, valves and stock cam next week with the wire looms.
I'll be sure to take pictures.

[Pcxdemon]

Yeah it's just a crazy idea.
I have everything I need for my engine rebuild now.
Only missing some connectors and wire loom from Yuminashi, I found a guy who bought a complete set from Yuminashi and then sell his bike with only 6000km on the set, so saved some serious money there.
1/ 31mm Throttle body
2/ 31mm A type manifold
3/ CBR150 fuel injector
4/ B to A type wire loom
5/ 5 pin to 3 pin wire loom
6/ full Sonic valve spring set
7/ Cylinder kit from Yuminashi
I put out the Yuminashi cam btw, this guy has it too but it has some holes on the surface, does not look too good, I'll see if a stock cam can work well with this setup. I'll have my new 125 head, valves and stock cam next week with the wire looms.
I'll be sure to take pictures.

You should get also a yumi radiator cap with higher bar pressure. It may save you in case it overheats. If it does,red light will be on the dash. Stop! Turn the engine off,let it cool down and then refill the radiator whilst running the engine and bleed it well for like 5 minutes while squeezing the top and bottom radiator hoses. You need to get every last bubble of air from inside..
The reason it may and i say may ,is because its always a possibility which only really once happened to me with yumi kit. When i rode it "full throttle" on the highway 110+kmh for 40min non stop" and then i suddenly came of to a service station to refill. It was a 5 min stop with no signs of overheating till i jumped back on it and rode 500m down the road and i saw a red temp light on. I guess i shouldn't have turned the engine so quick and had it cool down first. Happened so quick,but its important to shut the engine asap to prevent head warping as all the coolant will escape via radiator cap in to the top up container but it wont go back down due to air lock...The thing is, the 125 head water jacket ports don't align all that best about 35% less with bbk kits so if unlucky or pushed hard for a longer period of time it may tend to run with higher temps and also a small exhaust port will run quite hot comparing to slightly bigger ports so all that ads up. The higher pressure radiator cap may help just that little bit to keep water in the radiator instead of escaping and overheating..
As i said,it only happened once to me and because of what i described but otherwise never gave me a problem again or before that time..Also to consider is a spray on copper headgasket. You just spray and coat the gasket with it and gives you that bit extra buffer and protection for better seal.
Koso temp meter is a good addition to have to keep an eye on things while riding although it gave me little warning when temp shot from 91c to 135c in a mere seconds but its still useful sitting at lights and keeping an eye for it incase it creeps up slowly..

[BPT7594]

Thank you for your concerns.
I'll be sure to install that in 2 weeks or so, the budget is kinda tight after getting all 7 of my dogs vaccinated
In the mean time, I hope I won't run into anything dangerous, since I don't ride at 110km/h basically because there's no such road in Vietnam that allows it and I'll get into trouble with the police so my top speed would be probably 100km/h for like 10 seconds. I'm also not too keen on top speed, I'm more into acceleration and the thrill of getting pushed back into my seat and doing some wheelies
I did get the copper gasket set from Yuminashi, installing it is my mech's job.
Did you set your valve clearance like Reggy suggested Vlad? My mech said 0.05mm for intake and 0.08mm for exhaust is too tight/little and the metal expansion will set off valve timing, combustion chamber sealing and everything. Reggy insists on his suggestion and I know he has his reasons and knowledge, just what is your experience?
Something like this?

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[Pcxdemon]

I used that silicone once but didn't get good result. If you would to use it it would have to be really thin layer as any more will expand over the water ports and clog them up!
Copper spray is best, comes in aerosol can..
With regards the valve clearance, are you concern for both IN and EX or just EX? Maybe your mech is right..with a takegawa cam clearance was a lot bigger. Maybe little bigger gaps would be safer option like 0.08 for IN and 0.15 for EX?

[BPT7594]

Then I'll try to find some copper spray or just rely on my mech, his 35 years of experience tells me I can trust this guy
I'm concerned about both IN and EX.
Personally, I think 0.05mm and 0.08mm is too small. But 0.05mm and 0.08mm is what Reggy, the guy who makes the stuff recommends so I guess he must have his reasons, I'm not putting the high camshaft in anyway, it has some small holes inside the cam lobe, maybe the guy who bought this got unlucky and bought a lemon, Reggy said he would replace it with a new one. So I'm waiting for now.
However, I mentioned directly to Reggy that I intend to use the stock camshaft he still recommends 0.05mm IN and 0.08mm EX, even for a stock cam and he insists that more clearance would cause some tickling. When my scooter is full stock, I don't notice anything so maybe my mech who wants to go stock valve clearance is right, guess I'll have to disagree with Reggy, but if anything's wrong, my mech can change the valve clearance in about 20 minutes, give or take. Anyway, do the valve clearances have anything to do with a valve spring hardness? I'm putting in Sonic springs so I'm a little curious.
Here are the pictures of the Yuminashi camshaft, it's the RR version, I'm not accusing anything here, just posting pictures. Remember, Reggy himself agreed to replace it right after seeing the pictures so they are just for reference. Dealing with Yuminashi has been one of the most pleasant and informative experience for me and my friends. Can you check your camshaft surface Vlad for anything that resembles these?

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This is a CBR150 throttle body. I guess Yuminashi just got them from Keihin and done some work with polishing the throttle body intake, I guess you get what you paid for. They did a fantastic job polishing it. Just throwing it out there, if you manage to get your hands on a spare CBR150 2014 throttle body, you can save yourself a little money, but if you do decide to buy a new one, it's better to just get it directly from Yuminashi since the price for the throttle body alone bought from honda is about the same as the mirror shine polished one from Yuminashi, you still have to buy the A type manifold, if you have a PCX 125 1st gen or you can order the manifold from Honda and bore it up a little then it's fine, but you'll still have to buy some rubber connecting things from Yuminashi.

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This is completely unrelated, but the guy who sold me his kit also has that spare CBR150 2014 throttle body on sale. The price is 150$. It's still new, if anyone is interested please inbox me.