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Valve clearances on a new 2018 PCXneeded adjustments

Posted: Thu May 09, 2019 3:02 pm
by Inoplanetyanin
So i've taken my 2018 PCX apart at 1100 miles to check the valves.
Both exhaust and intake valves were too tight. The intake was at the lower limit of acceptable (with three gauges, only the thinnest was barely able to fit).

With the exhaust, even the thinnest acceptable was too thick and would not fit, hence needing adjustment.

I am glad I checked.
I am waiting for hondabond sealant to dry up on the valve cover gasket, then checking that it runs well and putting everything back together.

It took me about 2 hours to take it apart, slowly, for the first time. I only broke one clip in the top cover of the grab rail, when i pulled it sideways instead of straight up. It's a non essential clip and I will try to superglue it.

Bottom line, don't wait with the valve clearance check. If your engine is running with valves that are too tight, you run the risk of wearing out the valve seat prematurely or burning the valve, if it's an exhaust that can't fully open.

Lots of bolts and screws have to come off to get to the valves, make sure you are organized and if needed, record or video record steps and parts initial positions.

Let me know if you have any questions.

Re: Valve clearances on a new 2018 PCXneeded adjustments

Posted: Fri May 10, 2019 4:45 pm
by Inoplanetyanin
Here is a video of the engine start. Runs smooth. I definitely recommend the adjustment for those who are on the fence.

https://www.youtube.com/watch?v=_gtL9ef7gVw

Re: Valve clearances on a new 2018 PCXneeded adjustments

Posted: Thu May 16, 2019 6:29 am
by accyuklad
I will check mine on safe side next week but going to be a pain to check since you after remove the all back end bloody daft design idea

Re: Valve clearances on a new 2018 PCXneeded adjustments

Posted: Thu May 16, 2019 8:21 am
by homie
First I congratulate you sir on your diligence and timely deconstruction of the challenging valve clearance adjustment on a Honda PCX. If its any comfort to you I broke the same tab on one side of the grab rail cover as well and it made no difference to use the 20 dollar part with a broken tab if we are talking about the same tab. Its a tiny quarter inch long 1/16 inch protrusion on each side of the forward end of the grab rail cover. I had a 2015 model so there might be a newer design in cover since then. Maybe post a picture for us so we can all see exactly where to be more cautious when pulling off the grab rail cover.

Clearance was tight but within 'inch' tolerance plus or minus .001 in. I'm wondering after seeing your experience if inches were considered would you have read a more favorable result over metric. But i'm sure this is a dumb question and the more accurate would be mm's. I rode to 7k with tight clearance with the understanding these would wear into spec and go much further before needing to be brought back into spec, maybe never in the life of ownership.

But I was there like you and enjoyed the job more than most... I hope you did too. Good luck, ride safe and be well sir.

https://www.youtube.com/watch?v=n4hbzE0 ... l&index=12

Re: Valve clearances on a new 2018 PCXneeded adjustments

Posted: Mon May 20, 2019 7:15 am
by Inoplanetyanin
Thanks for the kind words, homie.
Yes, I think it's important to have the valve be in spec.
The tail rail where the clip broke had to be lifted up only, not to the sides and not with any tool, so if one carefully pulls it up, the clip will most likely stay intact.

I am not worried about replacing it or the rail because there are many other points that will hold that panel in place.

As to the units used, I used millimeters. But inches can be seen on the same gauge so I think there is no difference.

The design is peculiar but people get used to removing the panels and with practice, can be pretty fast at it, like these guys:

https://www.youtube.com/watch?v=j9F-7USH2bc&t=633s

Re: Valve clearances on a new 2018 PCXneeded adjustments

Posted: Mon May 27, 2019 11:07 am
by retry
1 TIP: do your first adjustment and forget about it, until you can feel that bike rattles or sounds strange because doing it every 5k miles it is nonsense.

Re: Valve clearances on a new 2018 PCXneeded adjustments

Posted: Mon May 27, 2019 2:01 pm
by mymitzi
Have to agree with Retry. Set em and forget em. Bought my 2013 PCX with just under 2100 miles. Have yet to check valves.
Currently have 49,928 miles on it. Planned to check them when it started acting up. Never did. Experiment continues.

Re: Valve clearances on a new 2018 PCXneeded adjustments

Posted: Wed Aug 04, 2021 5:05 am
by PCX 125 CANDY RED
Mine is 2013, 10k now never checked. Hope to do it soon.

Re: Valve clearances on a new 2018 PCXneeded adjustments

Posted: Mon Aug 09, 2021 4:18 pm
by you you
mymitzi wrote: Mon May 27, 2019 2:01 pm Have to agree with Retry. Set em and forget em. Bought my 2013 PCX with just under 2100 miles. Have yet to check valves.
Currently have 49,928 miles on it. Planned to check them when it started acting up. Never did. Experiment continues.
Excellent.

The only time I'd check them would be if the bike started stalling or wouldn't idle and I'd exhausted everything else.

Re: Valve clearances on a new 2018 PCXneeded adjustments

Posted: Mon Aug 09, 2021 7:34 pm
by mymitzi
68 k and still running fine. MPG is actually improving........first sign of rough running/starting......will fiddle with it then.

Re: Valve clearances on a new 2018 PCXneeded adjustments

Posted: Wed Aug 11, 2021 1:39 am
by you you
mymitzi wrote: Mon Aug 09, 2021 7:34 pm 68 k and still running fine. MPG is actually improving........first sign of rough running/starting......will fiddle with it then.
That's a fair mileage, it'd be interesting to know what you have done routinely and otherwise.

Re: Valve clearances on a new 2018 PCXneeded adjustments

Posted: Wed Aug 11, 2021 11:35 am
by mymitzi
Nothing special.....oil changes @ 5k intervals ..........air filter replace @ 15 - 20 k . 3 Variators boss w/new rollers/slides. Replaced the clutch bearing.
Drive belt 3 times. High/ low beam wire and switch replaced. Think mpg has improved because of summer blend [fuel] and the extreme hot weather.
Front brake pads. Rear brake shoes still good. Oh yeah..............too many tires............darn..... probably forgot something??

Re: Valve clearances on a new 2018 PCXneeded adjustments

Posted: Thu Aug 12, 2021 6:47 am
by you you
mymitzi wrote: Wed Aug 11, 2021 11:35 am Nothing special.....oil changes @ 5k intervals ..........air filter replace @ 15 - 20 k . 3 Variators boss w/new rollers/slides. Replaced the clutch bearing.
Drive belt 3 times. High/ low beam wire and switch replaced. Think mpg has improved because of summer blend [fuel] and the extreme hot weather.
Front brake pads. Rear brake shoes still good. Oh yeah..............too many tires............darn..... probably forgot something??
You can't complain at that can you? Thank you for sharing the detail based on evidence/mileage.

MPG can go up in the summer as the engine reaches operating temperature more quickly.

Re: Valve clearances on a new 2018 PCXneeded adjustments

Posted: Thu Aug 12, 2021 1:45 pm
by mymitzi
You're right...."You You"...If it blew up tomorrow, [done riding today....too stinking hot!] it's been a sweet ride...........wouldn't feel cheated ........even a little.

Re: Valve clearances on a new 2018 PCXneeded adjustments

Posted: Thu Aug 12, 2021 5:00 pm
by Conelite
with only 1100miles, seems a little premature to adjust if they are still within tolerance.

Chances are if you ran it another 1-2k, they would self clearance. lol. Im all about being OCD but this seems too much but kudos for checking.

Re: Valve clearances on a new 2018 PCXneeded adjustments

Posted: Fri Aug 13, 2021 2:21 pm
by springer1
Chances are if you ran it another 1-2k, they would self clearance. lol.
Just wondering ..... have you ever experienced loose or tight valve clearances naturally correcting themselves over time? Not being critical, just curious if this can occur.

My experience has been that prolonged incorrect gaps sometimes create damage to the contact surfaces which appear as mars or other uneven damage. What then happens is that these make correct gapping impossible because the feeler gauge cannot seat on the actual contact surfaces. This causes the gap to then be incorrectly set moving forward which then accelerates trouble. I'm not saying this is common the PCX engine, but I have experienced engines which were not maintained well reporting incorrect gap due to damage to the contact surfaces.

Re: Valve clearances on a new 2018 PCXneeded adjustments

Posted: Sat Aug 14, 2021 4:25 pm
by you you
springer1 wrote: Fri Aug 13, 2021 2:21 pm
Chances are if you ran it another 1-2k, they would self clearance. lol.
Just wondering ..... have you ever experienced loose or tight valve clearances naturally correcting themselves over time? Not being critical, just curious if this can occur.

My experience has been that prolonged incorrect gaps sometimes create damage to the contact surfaces which appear as mars or other uneven damage. What then happens is that these make correct gapping impossible because the feeler gauge cannot seat on the actual contact surfaces. This causes the gap to then be incorrectly set moving forward which then accelerates trouble. I'm not saying this is common the PCX engine, but I have experienced engines which were not maintained well reporting incorrect gap due to damage to the contact surfaces.
And we are off again.....

Re: Valve clearances on a new 2018 PCXneeded adjustments

Posted: Wed Aug 18, 2021 10:51 am
by Conelite
springer1 wrote: Fri Aug 13, 2021 2:21 pm
Chances are if you ran it another 1-2k, they would self clearance. lol.
Just wondering ..... have you ever experienced loose or tight valve clearances naturally correcting themselves over time? Not being critical, just curious if this can occur.
Coming from the Honda Ruckus scene, We experience higher and tighter Intale valves but thats due to the intake valve getting beat to hell from over revving (stock Limiter is 9k, we spin them to 10k+).

I was being a little sarcastic in my post but from what I read in your post, the lash were still within spec.. I personally would rather have the lash on the tighter side of the limit than vis versa. That's how I have always adjusted valves over my 25+ years wrenching with no issues.