Tapping noise coming from bottom end of engine

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Re: Tapping noise coming from bottom end of engine

Post by Dragon_uk »

Had a look at 2nd hand engines and looks that water can get to magneto from top so guessing rust on it will be a normal scenario.
Bike has 13k miles on the clock and with this noise has done about 50-60miles.
Oil from new always castrol power 10w40 semi synthetic.
Might do screwdriver trick tomorrow
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Re: Tapping noise coming from bottom end of engine

Post by DAB »

Alibally wrote:I cant see thicker oil making any difference. It's only going to mask the problem.
If it masks the problem, wouldn't it suggest a bearing?
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Re: Tapping noise coming from bottom end of engine

Post by DAB »

Alibally wrote:I cant see thicker oil making any difference. It's only going to mask the problem.
If it masks the problem, wouldn't it suggest a bearing?
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Re: Tapping noise coming from bottom end of engine

Post by Alibally »

DAB wrote:
Alibally wrote:I cant see thicker oil making any difference. It's only going to mask the problem.
If it masks the problem, wouldn't it suggest a bearing?
It might. It would be more of a diagnosis aid rather than a fix though.
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Re: Tapping noise coming from bottom end of engine

Post by Mel46 »

Well I got a chance to listen to your video this morning and it definitely sounds like metal against metal. Can you take the belt off and run it with the side cover off, and then listen to each area again? That would eliminate anything beyond the engine itself. The noise seemed to be worse close to the airbox, but that could be because there is less between the engine and the outside. Once you have a better idea as to where you think the noise might be coming from, use that old screwdriver trick. It does work. Many of the old mechanics use to do that on cars.
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Re: Tapping noise coming from bottom end of engine

Post by Dragon_uk »

Mel had it running with no belt, variator, clutch, pretty much no drive attached at all. Still the same noise
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Re: Tapping noise coming from bottom end of engine

Post by Mel46 »

I was rereading this thread, trying to see if the oil pump has been covered. If the pump is failing, partially blocked, or weak the amount of oil getting to the rest of the engine will be below the required amount needed to lubricate the parts, and the sound would be similar to what you are hearing, yet you would not be able to tell that it was bad just by checking the oil level.

It says in the service manual that the oil pump can be serviced with the engine still installed in the frame.
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Re: Tapping noise coming from bottom end of engine

Post by Dragon_uk »

Ok. Got more info that I'm guessing would've helped from the beginning.
Last oil change was done just after noise started but unfortunately I wasn't there myself to do it and half blind old man said it was okay. Lucky enough my brother in law was there and just told me that oil had very shiny surface and looked like someone had put loads small metal flakes in it. (he's not a mechanic and didn't think it was abnormal)
So at least now i know that something is wrong with this engine inside. But having metal flakes won't narrow it to one part of the engine will it?
I think we gonna just buy another complete engine and try to maybe open this one up and see what the problem was and sell all the good parts to cover some of the costs. Or I'll keep it for 190cc conversion to put in mine.
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Re: Tapping noise coming from bottom end of engine

Post by Dragon_uk »

Time for a bit of an update.
Got second hand engine in the end so bike can be in use straight away, I've purchased another engine for mk1 pcx by the mistake to I've stripped it down to see all parts on pcx motor and to maybe use some to fix broken one.
I've stripped damaged engine and there are some slight marks on cylinder and piston so I've changed those two put engine together again and fitted in bike (it takes me about 2 hrs now to strip bike fully and swap engine and start it), but unfortunately no change the noise is still there.
My aim for next few weeks is to change head to eliminate another part of engine that could be faulty.
If this doesn't work next plan is to split engine in half and change crankshaft.
Will try to keep you guys updated. Just wonna get to the bottom of the problem in case it happens to any of us in future
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Re: Tapping noise coming from bottom end of engine

Post by homie »

If you find a noise then you're a whisper'er for sure. If not then maybe a liiiiiiiiiiittle crazy given all this effort to find one :D
So to be clear, you can tear down and get to a PCX engines cylinder and piston in two hours? That's pretty impressive, you must have done it several times?
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Re: Tapping noise coming from bottom end of engine

Post by Dragon_uk »

No no haha.
Two hrs to strip bike panels, take engine out fit new one and start it up.
Could probably do the complete engine change and put bike back together in less than 3hrs.
You know I'll time it in weeks time.
With engine on a table in my garage it took me also about 2hrs to change cylinder and piston.
Know pcx quite well now I could say
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Re: Tapping noise coming from bottom end of engine

Post by homie »

Dragon_uk wrote:No no haha.
Two hrs to strip bike panels, take engine out fit new one and start it up.
Could probably do the complete engine change and put bike back together in less than 3hrs.
You know I'll time it in weeks time.
With engine on a table in my garage it took me also about 2hrs to change cylinder and piston.
Know pcx quite well now I could say
That's great, they are looking for guys like you down at the Honda garage :D
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Re: Tapping noise coming from bottom end of engine

Post by Dragon_uk »

Might be but I think Mr Trump doesn't want any foreigners coming into the country lol
But who knows thanks for tip anyway as might reconsider if it becomes shit in UK after brexit thing.
What's your weather like over there as I like to ride bike 12months a year.
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Re: Tapping noise coming from bottom end of engine

Post by lolofigo »

Dragon_uk wrote:Time for a bit of an update.
Got second hand engine in the end so bike can be in use straight away, I've purchased another engine for mk1 pcx by the mistake to I've stripped it down to see all parts on pcx motor and to maybe use some to fix broken one.
I've stripped damaged engine and there are some slight marks on cylinder and piston so I've changed those two put engine together again and fitted in bike (it takes me about 2 hrs now to strip bike fully and swap engine and start it), but unfortunately no change the noise is still there.
My aim for next few weeks is to change head to eliminate another part of engine that could be faulty.
If this doesn't work next plan is to split engine in half and change crankshaft.
Will try to keep you guys updated. Just wonna get to the bottom of the problem in case it happens to any of us in future
I have pcx v1 cylinder and piston if you want one to rebuild the other engine. I'm in Swindon.

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Re: Tapping noise coming from bottom end of engine

Post by homie »

Dragon_uk wrote:Might be but I think Mr Trump doesn't want any foreigners coming into the country lol
But who knows thanks for tip anyway as might reconsider if it becomes shit in UK after brexit thing.
What's your weather like over there as I like to ride bike 12months a year.
Unless you are a refugee fleeing persecution from counties on the temporary extreme vetting list you have nothing to fear yet... but stay tuned ;) There is comfortable riding season here in Chicago from April - November. Maybe 7 months if lucky.
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Re: Tapping noise coming from bottom end of engine

Post by Gil »

Did you ever take a look at the timing chain tensioner. My scooter made a similar sound and it turned out to be the timing chain tensioner.

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Re: Tapping noise coming from bottom end of engine

Post by Dragon_uk »

Yes I've looked at it as intaken it out and looks as it works as it should.
Correct me if I'm wrong but if timing was a problem bike wouldn't start smoothly and noise would differ when operating throtle as in there would be acceleration and deceleration in timing. But will check it too since I've spare one.
Thanks for advice
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Re: Tapping noise coming from bottom end of engine

Post by Gil »

Dragon_uk wrote:Yes I've looked at it as in taken it out and looks as it works as it should.
Correct me if I'm wrong but if timing was a problem bike wouldn't start smoothly and noise would differ when operating throttle as in there would be acceleration and deceleration in timing. But will check it too since I've spare one.
Thanks for advice
The chain tensioner has a spring in it with a one way action on the plunger (rod/thing). On mine the spring had broken and the plunger was all the way in. The bike still ran and had full power, it just made that same noise. So with a loose chain the bike will still run. If the chain for some reason jumped a tooth or two on one of the sprockets, then the engine might have trouble starting or loos of power.

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Re: Tapping noise coming from bottom end of engine

Post by maddiedog »

Sounds like timing or exhaust gasket missing to me. I like Gil's suggestion of checking the tensioner if you're confident it isn't valve noise. Badly adjusted valves make a tapping noise too that sound like that.

When you took the head off and did the cylinder, did the cam chain guides look worn? Did you readjust and tighten the cam chain tensioner before assembly? Same part as in the above picture, here's what it looks like fully extended:

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This post: http://hondapcx.org/viewtopic.php?f=3&t=2939#p61935 (start at 4 or 5 pics in) shows how I retightened the tensioner during assembly. The PCX will make tapping if the chain has too much or too little slack, sometimes rasping if you rev hard and chop throttle.
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Re: Tapping noise coming from bottom end of engine

Post by Dragon_uk »

Maddiedog

100% sure valves are done correctly. Had them adjusted three times after noise started and three different guys with mechanical knowledge similiar to mine (Im a car mechanic after 5years technical school and always worked with cars/bikes as a hobby (got bmw e30 with 4.4V8)) had a look to double check I've done it correctly.
Cam chain guides looked all good.
Tensioner as far as I'm aware is spring loaded, you undo it by turning anticlockwise and it stays in this position, then when touched or turned slightly clockwise it adjusts itself back to tight position. (please correct if I'm wrong)
A lot of plans for next few weeks (valentines day, my mum is flying over for 8 days, got to do some write ups for my NVQ, etc.) but I'll be taking loads of photos next time this engine will be pulled apart and will put spare tensioner and both guides from my spare engine.
But first will just change head to eliminate valves and springs.
Few more times and I'll be able to give info on how to strip engine and put back together over the phone. I know every bolt size on bloody thing now.
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