Engine rattle

[Riejufixing]

[Pete.]

[Riejufixing]

[Pete.]

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[bikenut]

No time today, but, Does cmsnl show a needle roller little end bearing??

Just cause you may not need the exploded views on cmsnl, others may/will find them very useful !!!!!
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nuts about bikes

[bikenut]

You're right. I never knew that and have never seen an engine without a small end bearing before.


pick a jap 2 stroke, look on cmsnl exploded views for that bike, say an rd250 yam.......

now you know why cmsnl is so usefull, for warned, for armed.........etc..
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nuts about bikes

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[bikenut]

Huge que in post office so missed transport connection, so have some time...........

I live in Warrington ( i dont but hayho ) and need to get to Talybont ( which one i hear you ask ) .

How do I find my way to there?

Sat nav ( don't have that ), google earth ( don't have that at home ), i could ask someone ( they will send me to the wrong Talybont FFS_) ....or read a map.

Moral, if you don't know, ask, or find out.

I could always come to where I am now and use google earth, wow brilliant.

I expect to fix a lads cb125 but don't have a manual or even seen the bike yet.

I could ask, or i could go to cmsnl for the exploded views which will show me stuff like, does the engine have an oil filter screen, a centrifugal oil filter, screw valve working clearance adjustment method, cb points or cdi ign etc., etc.,etc.. It also shows where they are on the engine ! Brilliant and its FREE.

A picture is worth a 1000 words, and if a helper is looking at the same picture as me, happy days.

If you still don't know how useful cmsnl exploded views can be then you are probably beyond help, or have a brain the size of the planet.

Back to the cb125 thats making all that noise.

The cylinder head is now off as you have shown a picture of the piston crown. There does not seem to be the bright ring mark on the crown to show the crown has been hitting the cylinder head.

The big end may still be "slack" so check for that as mentioned earlier, just to rule that in or out.

With the cam chain arranged so the crank can be turned safely ( so chain does not bunch up on crank sprocket and cause problems ) set piston at half stroke, now rotate the crank everso slightly forwards and backwards to show any play in the big end.

If the piston stays still, and the crank moves slightly forwards and backwards say more than 2 degrees ish ( the less the better ) , then there is play, either in big end, little and/or main bearings.

Remember that this engine has a balance shaft system, maybe that's where the noise is coming from?

more coming......

https://images.cmsnl.com/img/partslists/honda-cbr125rs-2006-6-england-crank-shaftpiston_bigecpp4e1e__1500_6138.gif

I am assuming your exact bike is the one shown inn the above exploded view, as you have shown this view in an above post reply, correct?

The balance system has rubber "cylinders" that may act as a cush system for the balance weight.

The rocker arm pictures show black specks on the cam box floor, are they rubber i wonder, as you said you also replaced the cam chain tensioner?

Much bits of black rubber in the filter screen??

more to come......

https://images.cmsnl.com/img/partslists/honda-cbr125rs-2006-6-england-camshaftvalve_bigecpp4e1e__0300_a7bb.gif

The camshaft view does not show seperate cam bearings so they may be pressed/shrunk on, the end of the camshaft shows the cdi drive which may also be pressed or shrunk on, so as long as the shaft and bearings are ok, then leave alone probably......back in a moment.....

https://images.cmsnl.com/img/partslists/honda-cbr125rs-2006-6-england-cam-chaintensioner_bigecpp4e1e__0400_761f.gif

Correction, the bit on the end is just for the cam sprocket by the looks of..........

Those alloy "shavings", where could they come from?

Well from something made from alloy.........but the caged big end may well have a alloy ( or more exotic material ) cage??

more to come......

Correction....

"It's a 2007 RW6 (the carb version).".............turns out its a different bike to the views shown, slightly different animal, see crank view........
https://images.cmsnl.com/img/partslists/honda-cbr125rw-2007-7-england-throttle-body_big00028239e__1801_5199.gif

funny looking carb to me..........inj
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nuts about bikes

[bikenut]

"I still have 2 X TZR250's and a TDR250. I also used to have another TZR250 race bike and have rebuilt them many times.
They all have roller small end bearings, as has every other Yamaha and Honda 2 stroke I've ever refreshed, from DT50MX, MBX50, NSR125's to DT-E125."

"It's a new one to me."

We all live and learn, remember " Look and Learn" ( showing my age now ) , Look and Learn with the aid of cmsnl, its free!

There are other flavours of parts suppliers out there with exploded views, but i find cmsnl more practical as they list stuff like outboard motors, genies, agri machines etc.etc.etc., all in one place.

Make sure you are sitting down when you see the prices mind, but you don't have to buy from them ( i have in the past and still will in the future, eu dependent ).

No roller little end bearing is common practice in the 4 stroke world. Some have interference fit of gudgeon pin in rod eye, some have a pinch bolt arrangement, and there are other methods.
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nuts about bikes

[Ayrton]

Wow thanks for the awesome replies. Apologies if it's frustrating that i'm not just tearing into the engine, I'd like to do it but my brother is more hesitant since he doesn't know a lot about engines and has half a mind to just sell the bike. I really want to find out what the issue is though. We've both been sick the last couple of days otherwise I would have just done it anyway.

I think I was a little confused when I said what year it is. It's registered in 2007, but it's the 2006 RW6 model and definitely has a carb.

The cylinder head hasn't been removed completely yet, we just removed the bolts so we could get the rocker holder off. The picture you saw was from one of those mini cameras on a wire. I'll take it off and do what you suggest bikenut, I suppose the head gasket needs to be replaced now the bolts are loose anyway even if I didn't remove it? (I have a bad history of messing up the head gasket on these...)

In the filter there was lots of 'gunk' clumped together but I dont think anything looked like rubber. I'm not sure what you mean about the black specs, are you talking about the picture showing the bottom of the rockers? That's just my workbench. I haven't seen any black specs anywhere.

I replaced the cam chain pensioner because I read somewhere it's quite common to fail and when I took it out it felt weak. New one feels just a little better, but I think nothing was wrong with it and my assumption on the strength not being enough was wrong.

[Pete.]

[Ayrton]

Ok so bit of an update since I've not been able to look at the bike today, but I've got the tray of oil strainer crap with me and I've realised that hidden inside all that gunk crap was bits of black rubber. Theres a fair amount of it too so I have no idea how I missed it.

[stevo as b4]

I'd imagine that pinch bolt clamped gudgeon pins would only have ever been used in old pre-war side valve engines, which aren't really relevant to the vast majority of motorbike engines you'll see today.

[mattsprattuk]

Well isn't this fun.
Let's clear up a few things.

It's a plain bearing little end. No bearing cage

If you've removed your rockers, then head removal is only 2 bolts away (those 2x M6 ones in the cam chain tunnel). That's it.

I personally wouldn't bother replacing the head gasket as it's a stamped steel one.

My money is on worn rockers causing massive valve gap. Readjust and try again. If it's quiet. Replace the rockers
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Blue_SV650S wrote: it was a sh1te wheelie, but it proves that he can get it up in 3rd and can do angles. In summery, mattsprattuk is a gobby little sh1tebag, dopehead tw4t, but sadly for all of us, he probably isn't THAT full of sh1te!!
Kickstart wrote: Hi I tend to agree with Matt. All the best Keith

[Sister Sledge]

[Polarbear]

Is this STILL going on?

Just strip the fcuker down and tell us what you find.
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Triumph Trophy Launch Edition

[Ayrton]

Ok thought I would update this with what I found since it may entertain someone
Still unable to convince my brother to take the damn engine out and strip it down he fucked around with the cam chain tensioner and found the noise went away at idle if a longer one was inserted (the old one with something welded to it).
Must be a slack chain or worn guides so we whipped the tensioner guide out and it looked like this. I probably should have seen this when the head was off so I dont know how it was missed.

https://i.imgur.com/CoXVxi5.jpg
So new one of those and a chain was fitted but it still made a noise, this time it sounds less of a clicking sound and more chain rattle however.
Must be the other static chain guide I said, but he said he checked it and it looked ok Took the head back off and actually took it out this time and it's got some deep scratches and grooves, but not as much as the other one. It looks more like the chain has been running up the side of it though.

https://i.imgur.com/1BoI5BY.jpg

I'll keep the thread updated when a new one arrives. I just want to thank everyone for taking the time to help even when I haven't made it easy I can see why stripping the engine apart would have shown this stuff within 30 minutes but my brother has just been trying to cut corners to save time. He's learnt better now hopefully.

[steve the grease]

"But my brother has just been trying to cut corners to save time. He's learnt better now hopefully."

I learnt after working on Citroens for many years that very often' the long way' is the quick way.

Same with welding " I can't be bothered to clean it up properly , I want to do a quick job" yeah right.

[Easy-X]

Looks like a lot of chain slap wear. Either the guides weren't in right or the tensioner is bad. I'd replace all three.
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Husqvarna Vitpilen 401, Yamaha XSR700, Honda Rebel, Yamaha DT175, Suzuki SV650 (loan) Fazer 600, Keeway Superlight 125, 50cc turd scooter

[Ayrton]

[Easy-X]

Best of luck
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Husqvarna Vitpilen 401, Yamaha XSR700, Honda Rebel, Yamaha DT175, Suzuki SV650 (loan) Fazer 600, Keeway Superlight 125, 50cc turd scooter

[Ayrton]

Ok I've put the new guide and sprocket in but it doesn't seem to have made any difference. I was fairly convinced it's the chain causing the noise as it seemed to go away at low rpm when I put the extended cct in that I made and there was all that wear to the guides. I suppose theres not really anything else that would cause a chain to slap or wear like that that I haven't already replaced though?

[Riejufixing]

[Ayrton]