Tapping noise coming from bottom end of engine

[aguim]

Dragon,

I'm not 100% sure your tensioner should 'stay in- position' after winding it's spring up. I'd rather think
it should immediately un-wind. I have a little jamming 'insert' here, that I use to keep them in-
position while I reinstall them, lest they quickly expand...

Just to make sure about that tensioner, remove its cap bolt and use a small screwdriver to
'stabilize' it while the engine is idling. A frantically shaking screwdriver will automatically
indicate a faulty tensioner (twist it clockwise a bit, and the chain noise will go off).

Flashy metalic particles in the oil would rather point to a failed rod bearing, though...

[maddiedog]

I'm not 100% sure your tensioner should 'stay in- position' after winding it's spring up. I'd rather think
it should immediately un-wind. I have a little jamming 'insert' here, that I use to keep them in-
position while I reinstall them, lest they quickly expand...

This is absolutely true.

[Dragon_uk]

Two tensioners I've ever dealt with on pcx both stayed locked in up position but even a very jentle tap on them would unwind them straight away so it's not like they are staying in out position constantly.
I was thinking rod bearing too but top and bottom of the rod has only holes to get oil in and create oil film. I didn't separate big end yet but had a good look with torch and couldn't see any bearings there.

[tomtomclub2005]

Uhh. If cylinder and piston were marked have you checked the connecting rod? i had to replace all 3 when my pcx V1 got noisier and developed a shudder at idle. The mech showed me the marked piston and cylinder. I was given no explanation for this, apart that i had fallen once a year before and that when bike is lying on the side with the engine running the oil pump could be starved of oil. The whole thing lasted for less than a minute though to pick up bike again so i am not 100% sure that was the reason.

[Dragon_uk]

But this bike was never on its side with engine running, never starved on oil and the marks on the cylinder and piston are minor. Connecting rod is fine, it spins freely, doesn't get stuck and pin sits nicely inside piston between those to circlips.

[aguim]

Check the tensioner dynamic, not static ,operation. Very easy as shown above.

[tomtomclub2005]

Check the tensioner dynamic, not static ,operation. Very easy as shown above.

+1

[easyrider]

My vote = Exhaust noise .

[Dragon_uk]

Ok I went to Chiswick Honda main dealer to get #18 and #19 bearings so I can get spare clutch set ready for when my one goes. This is where we've bought two brand new pcxs from and there's quite few Polish mechanics. Spoke to one of them who looked at my video and suggested it is big end crank rod problem. I so want to strip this bloody engine again now and get to bottom of this annoying issue.
BTW it's not the exhaust. Trust me it ain't

[Mel46]

Well I am not a mechanic but I play one on TV, so..... :-) I just had to say that.

When we had our accident both bikes lay running on their sides until I could make my way over to turn them off. They seem to run fine now. I don't hear any extraneous engine noises and they definitely still have lots of pep.

[lolofigo]

Ok I went to Chiswick Honda main dealer to get #18 and #19 bearings so I can get spare clutch set ready for when my one goes. This is where we've bought two brand new pcxs from and there's quite few Polish mechanics. Spoke to one of them who looked at my video and suggested it is big end crank rod problem. I so want to strip this bloody engine again now and get to bottom of this annoying issue.
BTW it's not the exhaust. Trust me it ain't

Yuminashi sells con rod for pcx. Honda only sells whole set with crank shaft so have a look on yuminashi website if you have to change it.

Sent from my SM-N9005 using Tapatalk

[Alibally]

You could get a second hand engine complete off fleabay.

https://www.ebay.co.uk/itm/182354816835

Might be less hassle.

[Dragon_uk]

I have purchased another engine with only 6k miles and bike is onthe road again. I've also purchased another engine (don't ask why. My mistake, got mk1 engine, top fitting, doesn't fit any of my scooters) stripped it completely so can play now, this is why I'm trying to repair the other one. And I will! I won't give up untill the engine is running again.

[Dragon_uk]

Ok guys finally got bit of free time and this weekend will swap engines again. Fingers crossed it will run fine this time.

[Dragon_uk]

So engine went back in and it doesn't have that tapping noise anymore so it was crankshaft then.
On the other hand it run for about half a minute and then stoped, started again and run for about 15sec. Starting it was getting harder and harder. Wouldn't go on higher revs what so ever. Every now and then comes with flashing EML and it shows code 52. Towards the end it would only turn over once.
Checked valves posision and it all looks fine to me.

Link to video of it not starting
https://youtu.be/d_5ZoEWmGG4

Any ideas?