The Honda PCX / Honda Forza / SH Forums

Your predominant source of information for the Honda PCX 125, Honda PCX ESP, Honda PCX 150, and Forza. Now featuring a SH300i / SH150i subforum!
It is currently Sun Feb 18, 2018 12:23 am

All times are UTC - 5 hours




Post new topic Reply to topic  [ 51 posts ]  Go to page Previous  1, 2, 3
Author Message
PostPosted: Sat Oct 28, 2017 2:14 pm 
Offline
Regular User
Regular User
User avatar

Joined: Mon Nov 09, 2015 10:20 pm
Posts: 355
Location: Watsonville, CA
Year: 2013
Color: black
JaeMelo wrote:
alx123 wrote:
I always believe that the engine will warm up more quickly when running than when it's just idling.

That is true but you need to understand the point of warming up the engine and oil to get the big picture. To make things easier I'll just spill the beans.

Different metals expand from rising temperatures at different rates. Aluminum expands quicker then cast iron. Do you know what happens when you do not warm up a cast iron block/ or even a cast iron sleeved block with an aluminum piston?! You end up with nice juicy score marks from the piston expanding too fast in the bore to keep up. In addition the whole point of the oil warming up is so that oil can reach its peak lubricating ability to protect the engine.

Banging on your motor with cold oil is the last thing you want to do. It introduces accelerated wear and tear; in addition when oil is cold the oil is thicker making the oil pressure higher. Oil pressure rises as rpms rise. All the people with filthy oil tubes on their air boxes are guilty of this. That tube in the back is a good indicator of blowy/excess crankcase pressure which occurs from simply not allowing the engine to warm up..

However these motors are pretty tough so even a fool could get away with being reckless however if you have a Yuminashi 164cc kit with the cast iron sleeve you'll probably score the bore and piston skirts up being impatient/foolish.




I like your explanation of why we need to warm up our scoot. Aluminum does expand faster than steel. I think the amount of clearance between the piston and the skirt come into consideration when it comes to warm up time. Vehicles with smaller clearances, like racecars and high power sports cars, are more sensitive to warm up times.

I'm not too diligent on my warm up routine, most times I let it warm up as I put on my jacket and helmet. Then it takes me a few minutes to get to the Highway, which involves wide open throttle. Before my PCX, I was used to turn key and go. The only bike I used to warm up was a Yamaha V-Star 250, something about the choke and cold starts. I sold that thing, not as good as scooters. On a side note I will be adding a water temperature sensor to my scoot. It will be interesting to see how long it takes it to warm up.

One thing is for sure warming up the scoot does no harm and is most likely good for the longevity of the motor.
Gil

_________________
ImageImage
    2013 Honda PCX 150, NCY Variator kit, Dr Pulley 12g Roller weights
    IRC tires, LED driving lights, Besten trunk


Top
 Profile  
 
PostPosted: Sat Oct 28, 2017 5:28 pm 
Offline
What's a wot?
What's a wot?
User avatar

Joined: Sat Jun 30, 2012 5:37 pm
Posts: 8148
Location: Lying in the gutter in the centre of the universe
If you think "warming up" is important due to the different coefficients of expansion and contraction do you also "cool down" in the same way?

_________________
Flu based abstinence


Top
 Profile  
 
PostPosted: Sat Oct 28, 2017 9:38 pm 
Offline
Forum Benefactor
Forum Benefactor

Joined: Thu Jun 22, 2017 10:28 pm
Posts: 206
Location: SE PA
Year: 2018
Color: white
Quote:
Funny, I recall seeing a person on here with score marks along his piston skirt and blowby past the oil scrapers. In addition the clear tube at the end of his air box was disgusting and full of oil which I'm sure you know what that means...

OK, I know this quote was written a while ago but ....... Well, I'll admit that I'm not sure that I know what that means. I'll need to look in the Service Manual, is there a PCV valve that feeds from the crankcase to the airbox - and the thought is that the crankcase is getting pressurized from blow-by ?

I never had blow-by on my Norton, just 2 pistons rising and falling simultaneously (like all Brit Twins) which caused pressure havoc in its smallish pre-unit crankcase. The o/p from the crankcase vent (they didn't call it a PCV) was so normally oily that I re-routed it to just above the drive chain which kept the chain nicely lubed and insured the frame didn't rust. I figured it was a marvelous hi-tech innovation LoL.

I didn't know that failure to let an engine warm-up would gall a piston.


Top
 Profile  
 
PostPosted: Tue Oct 31, 2017 1:05 pm 
Offline
Powered by angry squirrels
Powered by angry squirrels
User avatar

Joined: Mon Oct 23, 2017 3:06 pm
Posts: 188
Location: Milwaukee, Wisconsin, U.S.A.
Year: 2017
Color: PearlDrkAshBlue
gn2 wrote:
If its on the centre stand the rear wheel is in the air so no matter how hard you rev it the thing's going nowhere.

And you don't need to warm it up, it's ready to go as soon as it starts.

I meant side-stand, be near your ride so it doesn't take itself off the side-stand, of course it won't go anywhere on the center stand...thank you.

you you wrote:
If you think "warming up" is important due to the different coefficients of expansion and contraction do you also "cool down" in the same way?

Kind of...if the cooling fan on a bike is running I wait until it evacuates the extra heat and shuts off, then I shut down the machine. On a turbocharged engine the last mile is done "really easy" so everything cools down. I've seen other people crack exhaust manifolds, weld valve seats, score cylinder walls with rings that got heat-soaked, etc. It could be I'm over-cautious.


Top
 Profile  
 
PostPosted: Tue Oct 31, 2017 3:32 pm 
Offline
Frequent Poster
Frequent Poster
User avatar

Joined: Tue Jan 17, 2017 1:56 pm
Posts: 1309
Location: Old Saybrook, CT
Year: 2017
Color: White
To warm up or not to warm up. . .that is the question:
Whether t'is nobler in the mind to suffer
The slings and arrows of outrageous fortune
Or to take arms against a sea of troubles
And by opposing. . .end them. :roll:

T'is better to have warmed up and trashed an engine than to have trashed an engine and never warmed up at all. :lol: o_O 8)



Top
 Profile  
 
PostPosted: Tue Oct 31, 2017 5:10 pm 
Offline
Powered by angry squirrels
Powered by angry squirrels
User avatar

Joined: Mon Oct 23, 2017 3:06 pm
Posts: 188
Location: Milwaukee, Wisconsin, U.S.A.
Year: 2017
Color: PearlDrkAshBlue
To die, to sleep.
No more.
And by a sleep to say we end the heartache and the thousand natural shocks that throttle is heir to—’tis a consummation of fuel devoutly to be wished!

To die, to sleep.
To sleep, perchance to dream—ay, there’s the rub! For in that sleep of death what dreams of greater boost may come!





And from another passion:







Top
 Profile  
 
PostPosted: Wed Nov 01, 2017 5:26 am 
Offline
Forum Benefactor
Forum Benefactor
User avatar

Joined: Tue Dec 06, 2011 7:54 pm
Posts: 6122
Location: NE Scotland
Year: SV650AL7
Color: The correct one
WI_Hedgehog wrote:
gn2 wrote:
If its on the centre stand the rear wheel is in the air so no matter how hard you rev it the thing's going nowhere.

And you don't need to warm it up, it's ready to go as soon as it starts.

I meant side-stand, be near your ride so it doesn't take itself off the side-stand, of course it won't go anywhere on the center stand...thank you.


Have you tried starting a PCX with the side-stand down recently?
Go on, give it a go. :)

_________________
Four decades on two wheels has taught me nothing, all advice given is guaranteed to be wrong


Top
 Profile  
 
PostPosted: Wed Nov 01, 2017 8:56 am 
Offline
Forum Benefactor
Forum Benefactor

Joined: Thu Jun 22, 2017 10:28 pm
Posts: 206
Location: SE PA
Year: 2018
Color: white
PCX150Rider wrote:
To warm up or not to warm up. . .that is the question:
Whether t'is nobler in the mind to suffer
The slings and arrows of outrageous fortune
Or to take arms against a sea of troubles
And by opposing. . .end them. :roll:

T'is better to have warmed up and trashed an engine than to have trashed an engine and never warmed up at all. :lol: o_O 8)


Yah, I agree with warming up a bit, but I'm not too sure about the video. But the video's mention of oil reminds me - I know my pickup's valves clatter unless I let it idle for 30 sec or so in the winter so there must be some sort of oil flow factor involved. Doesn't matter what weight oil I use.

"Back when", I was always told the reason to not rev until the choke was off was because the additional fuel in the rich mix "washed" oil off the rings & bore. I don't know whether it's related to oil flow or rich mix or both, but it's probably best to keep the revs down until the choke is off or FI idle revs drop.


Top
 Profile  
 
PostPosted: Wed Nov 01, 2017 1:20 pm 
Offline
Powered by angry squirrels
Powered by angry squirrels
User avatar

Joined: Mon Oct 23, 2017 3:06 pm
Posts: 188
Location: Milwaukee, Wisconsin, U.S.A.
Year: 2017
Color: PearlDrkAshBlue
gn2 wrote:
WI_Hedgehog wrote:
gn2 wrote:
If its on the centre stand the rear wheel is in the air so no matter how hard you rev it the thing's going nowhere.

And you don't need to warm it up, it's ready to go as soon as it starts.

I meant side-stand, be near your ride so it doesn't take itself off the side-stand, of course it won't go anywhere on the center stand...thank you.


Have you tried starting a PCX with the side-stand down recently?
Go on, give it a go. :)

Crap, it won't! Well, I suppose that's reasonable. The 2016 motorcycle has to be in neutral, guess there's not really that on the scooter...older bikes had no such thing....


Top
 Profile  
 
PostPosted: Wed Nov 01, 2017 5:30 pm 
Offline
New Member
New Member

Joined: Tue May 23, 2017 3:37 pm
Posts: 29
Location: Birmingham,uk
Year: 2016
Color: Red
Well if my sleeve gets scored badly I get to replace with a Yuminashi big bore kit, nice! I typically don't let mine warm up whilst parked, but I do ride at low revs for first mile or so. I do wonder whether it is more important for bikes with manual gear boxes to warm up first. As the bike accelerates away and the rider goes through the gearbox, the changes in rpm can be quite dramatic. With our scoots having a CVT the increase in revs is comparably smooth. May all of our PCXs keep going for years to come.


Top
 Profile  
 
PostPosted: Thu Nov 02, 2017 2:02 pm 
Offline
Powered by angry squirrels
Powered by angry squirrels
User avatar

Joined: Mon Oct 23, 2017 3:06 pm
Posts: 188
Location: Milwaukee, Wisconsin, U.S.A.
Year: 2017
Color: PearlDrkAshBlue
I'd think it more important for CVT bikes to warm up as they [potentially] hit higher RPM due to the clutch, whereas a manual can be short-shifted.


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 51 posts ]  Go to page Previous  1, 2, 3

All times are UTC - 5 hours


Who is online

Users browsing this forum: Yahoo [Bot] and 4 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
Like what you see here? Buy the admin a beer! Donate at the link below:

Powered by phpBB® Forum Software © phpBB Group. Color scheme by ColorizeIt!