How-To: Valve Adjustment for Honda PCX

[Cascanciu]

Hi Marko, welcome to the forums!. I think I'm still the only Spaniard here so far, but it's good to see a Portuguese brother . I have a good number of friends in Portugal.

I can't help you with your query, though. My unit is at 6000 kms right now and I got a similar response from my dealer. Last time it was serviced they told it didn't make sense to dismantle the bike for the valve adjustment since the engine sounds very round with no clicking whatsoever. They suggested we leave it for the 8000 kms service. It's still under warranty so I guess it's their responsibility if anything goes wrong. I'll (for sure) hit the 8000 kms with the bike still under warranty.

If you have an air bubble in the fuel system, it looks obvious (to me) that you have to bleed the fuel system. How you can do that, I don't know, but there's people here who have the workshop manual. Hope anyone is able to give you a hand with it.

Good luck!.

[Marko]

Problem solved. When doing the valves, I also changed the plug. When replacing, I dropped the plug, but didn't check it before refitting. When I finally found the problem, the plug gap was almost closed, a few thou at the most. Amazed it ran at all.
Forty years of servicing my own cars and bikes (first scooter), but still do something so dumb!
Incidentally, it is much easier to replace the plug when the scoot is on the side stand than on the centre stand.

[Marko]

Hi Cascanciu, actually I am English, but live in Aljezur, Portugal. There is a Portuguese PCX forum that I follow, and while my Portuguese is OK I would rather write in English. Also, the English language forums are so much bigger, so more likely to get useful info. I notice that you are in Asturias, a really nice area of Spain, great roads for the scoot! I once competed in the Asturias International rally, 1984 if I remember correctly, great rallying roads too.

[Cascanciu]

Hi Cascanciu, actually I am English, but live in Aljezur, Portugal. There is a Portuguese PCX forum that I follow, and while my Portuguese is OK I would rather write in English. Also, the English language forums are so much bigger, so more likely to get useful info. I notice that you are in Asturias, a really nice area of Spain, great roads for the scoot! I once competed in the Asturias International rally, 1984 if I remember correctly, great rallying roads too.

Ooops! . Welcome anyway, then, there are quite a few Brits in this forum .

I know what forum you mean. I wanted to have a look but they required registering and since I can't write a decent Portuguese, I didn't bother. I can speak Galician so I can communicate with the Portuguese more or less well, but writing would be a problem and, after all, in this forum I've found all what I needed, so far.

Great that you know my region that well and that you've participated in the "Príncipe de Asturias" rally. In 1984 I was 11 years old. Mum wouldn't let me go to see the rally . I saw my first ones when I was about 16-17 and keep great memories of that. Such an spectacular thing to see those M3, Cosworth, Integrale, etc... driven by men like Sainz, Puras, Ponce, Moratal, Bardolet, Climent, etc... I am a rallying aficionado, too . The bad news is that I lost all hope to have the good old times back. Rally cars are no longer powerful RWD or AWD cars, and if I am to drive a few hours, stand in the sun (or in the rain), eat sandwiches and be uncomfortable for a whole day to see a rally, I want to see something worth being seen. And nowadays, few cars are worth being seen.

Glad you sorted out your problem .

[rp150]

I could not get the electrical connector apart. It looked like all I would have to do is push a small screwdriver in the slot and pull up. Did not work. I've broken connectors in the past and don't even want to think of it hear.
For other 1st timers. You will need a 9-mm wrench for the locking nut.

Thanks for the assist.

[rp150]

Upon going back to the origional post, it looks like the connector is the one located on the fuel tank, I was trying to take the one off the the top of the head.
Double good thing I did't break it.

[hytron]

Just wanted to add some additional info that could be useful. You don't have to necessarily remove the radiator or do anything on the right side of the engine. Instead you could just remove the plug, put a wood or plastic stick inside and rotate the engine using drive pulley located on the left side of the engine. Piston can either in TDC on compression (which is what you want) or between exhaust-intake of the next stroke. If valves do not move when you move crankshaft left or right by about 1/8 of a tern you are at the right TDC.
Maybe this makes things little simple....

Hope this helps...

[tomtic]

Some information for 125 ESP riders ....
The 2012 ESP model has some different fittings than those contained in the OP's photos. They are essentially the same, but the main differences are:-

1. Fuel line connector looks like this ....

P1050248_WEB.jpg (77.02 KiB) Viewed 14881 times

2. The radiator fan markings now look like this ....

P1050259_WEB.jpg (37.59 KiB) Viewed 14881 times

I checked my valve clearances today at 5000 miles and they were exactly mid-tolerance. I won't check them again until 10,000 miles at least.
Also changed the spark plus as per service schedule and it looked very clean.

[kevinm]

I just completed my PCX150's first valve adjustment at 700 miles. Here's what I found:

Intake was at about 0.09 mm - tight but within spec.
Exhaust was at about 0.19 mm - tight and not within spec.

I adjusted both.

[sleepnot]

Verify that the index mark and cutout on the fan line up again, and verify that the index line and the punch mark on the camshaft line up pictured below:

Hi,

New here. I recently bought a second hand PCX 125. With the information I found here I managed to check the valves and get everything together again. But it wil be a loooong time before I check those valves again, I assure you

But I was wondering, isn't it sufficient to check that the punch mark on the camshaft is lined up? I had the impression that when that punch mark is lined up then the index mark and the cutout fan are always aligned too? That would reduce the work a bit.

I did not disconnect the fuel pump connector either. I suppose this is only an extra safety precaution?

[Slickvic]

Verify that the index mark and cutout on the fan line up again, and verify that the index line and the punch mark on the camshaft line up.

But I was wondering, isn't it sufficient to check that the punch mark on the camshaft is lined up? I had the impression that when that punch mark is lined up then the index mark and the cutout fan are always aligned too? That would reduce the work a bit.

Yeah that was my thought too. Hopefully those who have done the procedure will chime in. This might be a case of the factory service procedure going a bit overboard.

[hawkeyegirl]

Urbanian,
I live in St. Louis, too. Do you mind sharing your mechanic's info? I've been going to Flying Tiger, but I'd appreciate your referral, too! Thanks!

A lot of enthusiastic self-tuners here. Congrats all.

I have the amazing good fortune to live 1.5 blocks from one of the most highly respected indy scooter mechanics in the region. Dropping off the scoot whenever, for whatever, and knowing it is in the master’s hands, makes my riding experience just that much more carefree. The PCX is economical enough that I can well afford a few $$$ to have it looked after by the best. I plan to have all service done on schedule. It’s a codependency I happily indulge.

My first scooter, a piece of Chinese junk, improved substantially with every visit to the mechanic. After the third visit, it was drastically better than when brand new. On the other hand, when I took in the PCX, I think my man was a bit disappointed he couldn’t improve on perfection. BTW, the valve inspection revealed they were dead on.

[sendler2112]

I did my first valve adjustment on the PCX150 today. The miles have been racking up fast and I didn't mean to let it go this long but I have 7,000 miles on the bike already. The good news is they were still both very close. The exhaust valve was .001 inch loose and the intake was only .001" too tight. Less than a 1/16th of a turn of the screw adjuster had them set. It took me a solid 3 hours from start to finish but next time I could do it much quicker. It is really not necessary to remove the lower body work to mess with the radiator or to open the fuel lines for any reason. Just remove the tail trim, grab handle, gas flap, side work with tail light still attached, storage compartment, battery tray with battery still connected, lift up the injector to get the bracket guiding some hoses out of the way, and the valve cover will come out to the top. take the cover off from over the front pulley so you can turn the engine with a socket and watch each valve open and then close and then turn a little more so you know you are on the base circle of the cam. No need to align any special mark on the fan. Measure anywhere around the base circle, it will be the same. This saves you from pulling the lower bodywork and radiator. I re used the valve cover gasket. Rubber gaskets can generally be reused many times and never leak.
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I also measured my belt and it is still 21.5mm as it was at 2,000 miles. There is some slight wear that can be felt on the outer travel of the front pulley but top speed is still good so the drive components are fine.
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[you you]

Excellent info, thanks

[Slickvic]

Thanx for taking the time to post the Info!!

[logepoge1]

Mine desperately need checked. At 1700 miles so will wait until 2500 miles to do it(will do it during quarter break)

[Mgalutia88]

How are you guys torqing your rocker arm jam nuts after you set the lash?

[maddiedog]

With a 1/4" ratchet. The torque spec is 10 n/m or 7 ft/lb.


A WORD OF WARNING FOR ANYONE DOING THEIR VALVE ADJUSTMENT:
We did Mel46's valve adjustment this last Friday. It went well, until we went to reassemble it. The head nuts for the valve cover are spec'd for 20 ft/lb of torque. We sheared one at 17 ft/lb of torque. Tighten them until they're tight, and BE CAREFUL not to overtighten. Luckily, the 3 remaining nuts held on just fine with no leaking. I'd stop at 12 ft/lb or so.

[Mgalutia88]

I can look it up I you guys want but when I was doing lots of work on Porsches there is a general torq spec based upon the bolt thread size. For instance anything that is 8mm (usually has a 13mm hex head) is 15ft/lbs. I understand that these bikes and Porsches have nothing in common. I'm just stating that there is a standard published that I may be able to get my hands on for grade 8 fasteners.

[Mgalutia88]

Are you using crows feet on the end I the torq wrench or are you tightening the lash jam nut until the lash doesn't move and then setting the torq?