2015 PCX 150 sounds like a Rod Knock

[you you]

So the same thing has happened before with only one common denominator?

[Old Grinner]

Junk..
still knocking away

That's a shame.

For about $2k you could have gotten a brandy new Agility 125.

It would be great if we all had "future vision".

Those costly mistakes in life could well be avoided.

[MichaelGee]

“The common denominator“
Funny way of putting it.. but yes..

Changing the oil is insignificant, or who does it..
Drain, filter, fill to spec..

That removes an additional common, me..


Back to PCX-
Since this Rod Knocking noise only occurs;
at speeds Above 15mph (enough of an rpm)
at even keel engine operations, Slight drag weight of scooter and I

I am still prone to believe it is not a Rod Knock crank bearing
This one would hear All the time, even at idle..

Variator removed still hear it, although i must fan throttle to get the needed torque strain, and then I can hear it until rpm has reached the new throttle position, short and quick..

Replaced injector (onTop of everything else I’ve done to this thing)
Guess I’m going to check o2 sensor prices now

No engine light, which should pop on Lean condition shouldn’t it ???

Anyone know how to Zero the ECM ???
ya know, the full throttle and release programming to calibrate the ECM

Battery disconnect is not how you do it, it’s a paper clip jump
and how do you read codes from ECM ???

[MichaelGee]

Here’s some funny stuff

Have a syringe, using this to pull tubes of oil out
and put All sorts of stuff in there, all making sure
to not overfill of course..

Correct hp4m oil 900mL (screen clean)
Two cough syrup cups of Motor Honey -no change
Two cough syrup cups of Petron Plus -no change
Two cough syrup cups of gear lube 90W -no change
Another Cup of 90W gear lube -no change

Each cough syrup cup is three syringes full
3 syringes out and 3 syringes in per cup, so 6 syringe cycles per cup
so each additive takes some time to do

Not sure how much “oil” is actually left in there

My jetski buddy stops by, notices my air pressure is low..
14 pounds front, 19 pounds rear
Off i go rattling to the gas station a mile away, they have the digital air pressure pump
29 LBS front 33 LBS rear

Bam it’s not so soft riding this thing anymore, still softer than China clone crap for sure

Less rattling now with rolling resistance reduced
Also noticed mpg sitting around 106 on the dash

My wife, my buddy, my brother Bruce, all say ride it till something Breaks, then you’ll know.. Brother Steve says, go pay the price for someone who has the Knowledge to hammer it in the Right Spot to fix it, even if you get the bike back at Christmas.. Honda Dealer

Now I’m thinking, with all this oil Thickening & no change, it can not be the crank area at all, maybe i was right with the spark knock Lean condition..

OR... just maybe a coincidence of timing, that some bolt or nut gradually worked loose “?” Tried recording the noise, too difficult to hear with wind noise, but decided to put phone on muffler side, same intensity.. Telling ya, i Don’t know where it is anymore, can’t pinpoint it at all

Above 15mph (Fifteen miles per hour)
anything Below 15mph SILENT SILENCE QUIET TIGHT Honda whirling sounding engine

New injector, all the oil swapping, i spent all of Father’s Day determined to find or silence the above 15mph rattle.. no go..

Leaning now towards Rocker Arm slides being worn, causing lateral clacking, but no that sound would remain on center stand.. so That’s not it..

i answer myself while typing..
Or post and re-read to deduce the content..

Not much hair left, starting to get a bald spot

[MichaelGee]

How about we try This “?”
Order a cooler or hotter spark plug “?”
Try that..

Now, which way does one go for a spark knock?
Cooler??

Give me your wisdom PCX Forum members..

[springer1]

How about we try This “?”
Order a cooler or hotter spark plug “?”
Try that..

Now, which way does one go for a spark knock?
Cooler??

Give me your wisdom PCX Forum members..

If you want to go that direction- instead just drain the PCX fuel and put it in your car. Then go to a gas station that sells high octane - and dial in the highest octane they have and first put a few gallons in your car to “chase out” lower octane from the hose that the previous buyer used - and then fill your gas can for the PCX so you get the “good stuff” for your scoot. Try that.

[MichaelGee]

Been doing that for Years..
Even explained that on page 1, i always give a gallon away to whoever is close..

But That’s not it..
Page 2 octane booster and everything else..
Tank is now Flushed, new injector..
This is My thread, so Back to page 1 for all that I’ve done..
But thanks for throwing input out here

I searched preignition and spark knock and ping
Boom there was my sound, on a Bicycle motor conversion adding Nitrous
Project Farm or something like that

https://youtu.be/Wmg0bzuO1Mc

In this video it speaks Directly on heat ranges
And SHOWS pre-ignition on a plexiglass engine

I don’t know why my compression or cylinder heat is so high as to cause knock
So after reviewing NGK nomenclature part lettering, I ordered an cpr8ea-9 plug, which is one heat range cooler..

Sure would be a great cheap fix.. Hopefully..

[MichaelGee]

what the F “????”

1st picture- one heatrange cooler plug 10minutes (TEN)
in TEN minutes it is White metal, this thing is Spark Knocking LEAN

WHY “?”
why is this thing running Lean

All I did:
-oil change
-spark plug
-air cleaner
-cleaned out cvt air vent
-added injector cleaner

Within 24hrs of Light use, knocking..
THEN all the Friggn work and replacements..

2nd picture is Original plug, notice wet oil “?”
and wetness of oil at spark plug hole

900mL is Too much oil??

[springer1]

The original plug looks either lean or a bit of bad spark timing. Correct would be grey not white, no blistering & less electrode erosion - that plug has both. The wetness isn’t necessarily oil could be rich which of course conflicts with lean. This is above my competence grade ( I stress this fact ) but the original plug’s condition IS from many miles. If faulty timing is in play, *SOME* EFI systems would sense the overheat and richen the mix which complicates the symptoms. I don’t know if the PCX would or not. But I’m not convinced that’s oil wet.

[MichaelGee]

Yes that is an old plug that was in there when I bought it, i stuck that one back in there after burning up the new plug with injector cleaner and octane booster, page 2 or 3.. darn thing was orange..

Everything was smooth and quiet for the 1st 5 days of zipping around subdivision and a couple 50mph runs to store a mile away.. Then i changed oil plug air cleaner, added injector cleaner and all Hell broke loose..

The white on them plugs is Lean Hot Detonation
Knocking happens only at even road speeds above 15mph

it’s severe enough to do that to a new spark plug in 10 minutes, with short knock cycles as sub speed is 15mph around here.. That’s Severe spark knocking..

Crank bearings and rod completely ruled out with all that I’ve done..
Which is a Good Thing but, now I’m burning up my piston, rings, and valves “?”

What the Hell..

[MichaelGee]

okay let’s see how sensitive these Honda engines are with air/fuel mixtures..
Before buying o2 sensors, fuel pumps, tps etc..

going to open it up again-
Verify clogged or open freely crankcase tube to air box
Verify all vacuum lines Tight, spray starting fluid around gaskets and such looking for an rpm change

IF crank vent free, going to plug it for a test
IF crank vent plugged, maybe the steamed oil will cool spark down

But what are the ODDS of coincidence, that something other than what i have done, is the culprit of almost exact timing ????????????

Don’t have $70 an hour for dealer
Nor do i like waiting a month before they Start on it..

[you you]

Strange.

I think you are right to chase an air leak next.

[Conelite]

If you think its lean, Instead of buying an O2 sensor maybe buy a wide band. We used a Sniffer to tune our 50cc Carb Honda Engines.

I run open intake and exhaust with stock ECU and dont get knock. Judging by your old plug, the white ceramic should be brown. You dont really pay attention to the electrode.

2db0bd89-f5df-4da5-a30e-f25fb9222c82.JPG (326.85 KiB) Viewed 1335 times

[MichaelGee]

Okay.. all put Back together..
Again........ no air leaks anywhere
Now, going to Rip it all back apart..
Still spark Banging away..

One good thing out of today, successfully zeroed ECM programming
This was tricky, my data connector is upside down, jumped wrong side..
and jumped the ECT sensor connector, Successful Program

Shouldn’t the o2 sensor be triggering to ADD more fuel on Lean sniffing of the exhaust “?”

Not sure if i posted this previously..
i only have 75% usable throttle, since i got it..
Full throttle is Less acceleration, than 75% throttle
Don’t know if this is normal, never had a PCX before..
at 55-60mph with my Lardass, I’m at 50-60% throttle to keep it there

i added injector cleaner Lubricant
It’s kinda thicker than fuel -much

Think I plugged up my fuel filter, or my pump “?”
Weakened it?

i don’t Fn KNOW.. but it sounds reasonable..
Just found out our pumps are Resin based plastic

Going to test fuel Flow 2.77oz in 10seconds
Can’t test continuous pressure 46lbs, don’t have a gauge

OR
i could just get a whole unit New with a fresh clean filter for $75
Then rip it apart “?” No money left for this..

OR
just rip it apart and Clean out filter to like new “?”

What?
What I gotta doo “?”

Ima gonna Rip it all outta the tank and clean the Filter

[Old Grinner]

Maybe I missed something . . . did you say you did a compression test cold?

[you you]

Okay.. all put Back together..
Again........ no air leaks anywhere
Now, going to Rip it all back apart..
Still spark Banging away..

One good thing out of today, successfully zeroed ECM programming
This was tricky, my data connector is upside down, jumped wrong side..
and jumped the ECT sensor connector, Successful Program

Shouldn’t the o2 sensor be triggering to ADD more fuel on Lean sniffing of the exhaust “?”

Not sure if i posted this previously..
i only have 75% usable throttle, since i got it..
Full throttle is Less acceleration, than 75% throttle
Don’t know if this is normal, never had a PCX before..
at 55-60mph with my Lardass, I’m at 50-60% throttle to keep it there

i added injector cleaner Lubricant
It’s kinda thicker than fuel -much

Think I plugged up my fuel filter, or my pump “?”
Weakened it?

i don’t Fn KNOW.. but it sounds reasonable..
Just found out our pumps are Resin based plastic

Going to test fuel Flow 2.77oz in 10seconds
Can’t test continuous pressure 46lbs, don’t have a gauge

OR
i could just get a whole unit New with a fresh clean filter for $75
Then rip it apart “?” No money left for this..

OR
just rip it apart and Clean out filter to like new “?”

What?
What I gotta doo “?”

Ima gonna Rip it all outta the tank and clean the Filter

The 75% usable throttle sounds odd.

Could be fuel starvation so I think you are right to check out the fuel pump and filter next.

[MichaelGee]

That’s what I thought You You
and then, what’s the 1st thing fuel injector cleaner hits?
The trash in the tank and filter, starts breaking down the trash

Tank drain to get additives outta there- fuel was Cloudy Yellow, and smelled funny.. Fuel was Not Clear as it should’ve been.. (page 2 or 3)

Remember all the grass plugging up cvt air vent and sticks jammed into center stand? it’s been Stolen, running around from the cops in fields Without a Gas cap and ignition lock switch

Maybe it was already partially plugged up and additives just finished plugging it up, injector cleaner finally did it in for minimal fuel requirements at even keel..

Sure it’ll pump fuel under Load and idle, but not Enough at even keel road speed that requires minimal consistent fuel stream.. pump straining all the time.. also explains 75% throttle, already maxed out fuel pump flow at 75% a physical fault..

Now does that Make Sense..?

So my Brother Steve, also thinks I’m logically on the right track and Donated to the cause..
New fuel pump assembly And o2 sensor ordered at 11pm last night..
He said Throw the o2 sensor in there too for shits n giggles..

Thank you Brother Steve
Holy Crap am i Thankful..
Big shout-out to Brother Steve.. “For Youuu”

[MichaelGee]

The knock is either metal on metal or from detonation. I'm still wondering about a faulty fuel pump. With the additives perhaps something was effected? The Forza models had problems with deformation (swelling) of the fuel pump inlet cover (resin material) causing interference with the impeller. There was a "Recall" that Honda posted to make good on the deal. Ethanol does strange things to some kinds of plastic.

Shout out to Old Grinner
Guess with my anxious demeanor, i passed right over this post..
Funny how i came across this Resin info, and it was already posted in this thread..

Still waiting on Adept Powersports to actually Ship the stuff to me..
Really didn’t want to drive back out to Lapeer, ever again..

Sure hope it is this..
Hopefully this will also cure the 75% usable throttle problem too
But, it does sound this way with reasoning..

[MichaelGee]

Question for Everyone “?”

Does your PCX make a click sound when touching the throttle around say 10mph ??

This thing Clicks..
Hard to keep 10mph without it making a click sound and wanting to take off..
This PCX doesn’t like to go slow..

[MichaelGee]

Still knocking lean..
Just over six hours Bustin butt in 93° sun beating weather

Still only 75% usable throttle
Still Spark knocking above 15 miles an hour

Old fuel filter was black with junk, and ripped

New fuel pump filter
New injector
Fuel line blown out clear

No Codes stored

Throttle “clicks” trying to keep slow pace
when it clicks it wants to take off, hard keeping 10 to 15 mph

Really tired of this fuel cut-off deceleration..

WTHell is going on?????

Had a new o2 sensor delivered, maybe that’ll help..

Then i should replace the IAC maybe it’s stuck Open allowing too much air
But Maybe, it’s the throttle position sensor, still functioning but lost it’s position, although i zeroed the ECM to set TPS.. but Maybe it’s That or This, or some of the other things, he’ll maybe it’s something I just don’t know about????????????????????????????

Anyone catching the attitude yet “?”

Does anyone’s PCX click when yer giving it gas at slow putzn speed????