phishypenguin wrote:Last service was 16,500 miles, but i changed the oil at 19,000 as they said to change it every 2,500-3,000. I thought that would see me through until the next MOT this month. It's difficult to see much of the bottom end through the gap, but from what I can see there don't appear to be any marks on any of the components. It looks like there is oil when you look straight down through the gap which seems odd.
The connecting rod gives a little movement from side to side which is normal I think. The piston though is quite tough to spin on the rod and I'm finding it hard to get it off/push the pin through. I've attached a picture of the area that I mean.
Which parts are the cams? And what do you mean by it doesn't look like it has been burning oil?
To remove the piston from the small end first remove the circlips. Pack the open crankcase with rags first
The gudgeon pin should then push out. If it doesn't try some gentle heat on the piston using hot wet rags. If that doesn't work buy a gudgeon pin press. They are only pennies
If you need to use a lot of force something is wrong
I was hoping to get some advice on what to do with my 2010 PCX. I've had it for two years and it has racked up 23k miles. I've always taken it to the Honda dealership for any work/services that it has needed, however I made the mistake of not checking my oil recently and two weeks ago the engine let go. At first it just coasted to a halt - then after waiting 5mins I tried to go on again as I wanted to get off the motorway I was on, but only managed half a mile before it started smoking and ground to a halt.
Upon taking it to the dealership, I've been told there is no compression and that they can't know for certain what the problem is without taking it apart but it would seem that the engine is seized. After being quoted £1000 for a rebuild I decided to buy something new, but I'm not sure what to do with my PCX now. I would like to have a go at trying to fix it myself, however I'm not sure what the cost of trying to do so myself would be and whether someone with no experience in this area could do so? Alternatively I was told by the dealership that I should just break it and sell it for parts or as it is - does anyone have any idea what sort of money I would get for breaking a PCX?
Any advice on this would be greatly appreciated!
Patrick
2 seized 125s recently, so I got a bit mixed up with the previous post. You don't make clear if you checked the oil after the seizure, was it low?.
The cams are on top of the cylinder head and are what pushes the valves down. Any scouring on the lobes (the point that pushes the valve down.
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That doesn't look like its been burning oil at all. With a. Spark plug that clean and such a clean head for 20k miles.
Might be an idea to check your cooling system, a major over heat would also cause something along these lines, especially if it kept running over and over again whilst overheating. Did you notice any lights on your dash?
I also noticed you was on a motorway when the engine let go, if it was burning oil, the head would heavy with carbon, and the plug would not look like that, but be heavily fouled.
Firstly, no, there was nothing on the dipstick when the engine went, so the lack of oil would seem to be the main culprit.
The spark plug definitely doesn't look like that picture! Most of the components look to be in pretty good shape. I've attached a picture of what I think are the cams - these don't appear to have any scouring marks on them at all so they're all good.
Getting the piston off the rod took a lot of force, far more than I think it should have, but the rod itself looks okay. I've attached a picture of where the piston ring goes into the eye of the rod. It looks like there's a groove in the eye of the rod, does anyone know if this is normal? I popped into the local Honda dealership today and the guy there said if the piston wasn't turning freely on the rod then I would have to replace the rod and whole bottom end part (crankshaft?) which would mean completely taking the engine apart - he also said the part to replace this would be £325! Given that the rod seems to be in fine condition, I was planning on just buying a new piston and ring and seeing if the ring would fit in as it should and if so, getting the cylinder rebored. It not, then I'll probably look into selling it.
strange, you wouldn't expect the engine to be so clean if was burning oil. The picture i put up is what a spark plug would look like if it was burning oil, looking at your pictures before the incident your engine seemed to be running really well with good valve colour and minimum carbon build up. not what you would see if its been burning oil for some time.
are you 100% sure the oil wasn't leaking?
Replacing conrods in smaller scooter engines isn't unheard of at all. parts for these engines are very cheap but labour intensive
In the UK there's no point trying to do major engine repairs on a PCX with new parts unless you can import them yourself from abroad.
A crankshaft is $70ish in the US and A
I'm not 100% sure there wasn't an oil leak, but I've never noticed any oil left behind where I've parked up and there was no indication of anything out of the ordinary prior to this happening.
Wow, parts are much cheaper in the US. The crankshaft looks fine from what I can see through the gap now, not to mention that I'd really rather that I didn't have to replace it as it looks like a pretty major job!
I'll buy a new piston and sort the cylinder out and see how it runs.
phishypenguin wrote:Lots of help and questions to answer!
Firstly, no, there was nothing on the dipstick when the engine went, so the lack of oil would seem to be the main culprit.
The spark plug definitely doesn't look like that picture! Most of the components look to be in pretty good shape. I've attached a picture of what I think are the cams - these don't appear to have any scouring marks on them at all so they're all good.
Getting the piston off the rod took a lot of force, far more than I think it should have, but the rod itself looks okay. I've attached a picture of where the piston ring goes into the eye of the rod. It looks like there's a groove in the eye of the rod, does anyone know if this is normal? I popped into the local Honda dealership today and the guy there said if the piston wasn't turning freely on the rod then I would have to replace the rod and whole bottom end part (crankshaft?) which would mean completely taking the engine apart - he also said the part to replace this would be £325! Given that the rod seems to be in fine condition, I was planning on just buying a new piston and ring and seeing if the ring would fit in as it should and if so, getting the cylinder rebored. It not, then I'll probably look into selling it.
Ooh can't tell for sure but that might be a plain white metal bearing. When the gudgeon pin came out was there an obvious roller or ball bearing in the centre?
If not doesn't look to good, seems like there is a fair bit if scoring on the soft metal surface
if your engine was burning enough oil to suck your sump dry between services, you spark plug would look like this.
No it wouldn't. That has been burning a lot of oil over a protracted time. Either a two stroke or a larger capacity muticylinder engine ran with a cylinder down for a long time. A very long time....
The PCX doesn't have the amount of oil in its sump to cause this type of residue.
I can't see any bearing on the rod itself nor on the pin. The pin is scored about 3/4 of the way around - I've attached a picture of it. It looks like it was part of the damage from the seizure.
Apologies if it's a naive question, but would the scoring in the middle of the eye of the rod have much of an impact on the running of the engine if I replaced the piston and fixed cylinder and if so, how?
One other thing I've noticed is that the piston is only scored on one side, the other side is completely smooth and without any marks - not sure if that means anything or is just coincidence!
phishypenguin wrote:One other thing I've noticed is that the piston is only scored on one side, the other side is completely smooth and without any marks - not sure if that means anything or is just coincidence!
Always awkward with pictures and others will have their opinions but I would have written off the piston, rings, pin and rod by now. Mains and big ends may be OK but might be worth checking
You might be able to get the rod bearing surface remetalled
Pcx uses oil via crank breather hose from top of the head cover via air box where it's sucked back in to the engine where it mixses with fuel and combusts. It does that nice and slowly so one never notices but leave it long enough between oil changes and that'll happen. I change my oil every 1500km to be safe...
you you wrote:
Always awkward with pictures and others will have their opinions but I would have written off the piston, rings, pin and rod by now. Mains and big ends may be OK but might be worth checking
You might be able to get the rod bearing surface remetalled
You're right, the piston, rings and pin will definitely be replaced, but if it's just the eye of the connecting rod that is scored slightly, I'd rather try to fix that as it is. I'll take a look at the big end, but it seems as though you can't see much without taking the whole bottom end apart.
And if the wrist pin is that badly damaged, the bottom end has seen better days. You don't want to go through all of this and have the bottom end get noisy in 1,000km. Did you look under the cam at the bearings? That is undoubtedly shot so you need a head. Might as well get an aftermarket big bore/ stroke kit with the bigger head and cam and injector. And then you will also need a fuel computer and a mixture logger so you can tune it. Now you are headed for the far side of $1,700/ 1,100 pound.
As I see it, the cost of new parts against the value of a 23,000 mile 2010 PCX means you have two options.
1: sell it as is and buy something else
2: get a replacement used engine from a local breaker with a guarantee that its a runner
If it was me I would favour option 1
Whatever you do FFS don't arse about fitting "performance" parts on an already scrap engine.
Four decades on two wheels has taught me nothing, all advice given is guaranteed to be wrong
