LOUD ticking noise???

[Zenith]

The bike is a 99 CR125 with a reasonably new piston(c20 hours). When the bike is idling it makes a loud noise that I would describe as ticking. It sounds like the noise the kickstarter makes when returning but louder. When you rev the bike the noise seems to go away but it could be just that it speeds up and can't be heard:think ? When the engine is dying after you press the kill switch the noise is really obvious. The noise only started happening after last weekends MX practice day, the track was wet so LOTS of revs were required!
Would it help if I recorded the noise for yis'?
I just want to know what tends to cause these noises? Is this the noise usually described as knocking?
A local mechanic said that it is nothing to worry about but we just want to be sure....

Thanks for any thoughts,
Zenith

 

[marcusgunby]

Zenith load ticking isnt good but the Cr engine does make a fair bit of noise even when new-could you record it for us.it could be the piston slapping in the bore-20hours is alot for some pistons.The alu frames tend to amplify noises especially if you have a skid plate.

 

[slideways11]

take the chain off and spin the countershaft sprocket with your finger, if it is ticking you have chipped a tooth off a gear.

 

[Zenith]

Finally...

Right well I went down and listened to the bike again out of the shed and it doesn't sound as bad but there is still a very definite ticking noise. The bike was ridden on Saturday with no problems but still..

Here is a recording of the noise....

It's a 300Kb, if it doesn't work reply and I'll re-upload it - ftp was reporting some strange errors when I put it up.

Thanks

 

[spanky250]

I did think that I could hear a little slap, but otherwise, it sounded perfectly normal to me.

 

[Zenith]

Excellent:aj: Glad to hear it...

Just out of curiosity is the background ticking noise what you described as "slap"?


Thanks

 

[IRONDOG]

Good recording- that's definitely piston slap, way to much clearance. Heard it many times before. That piston's talking to you, saying," Change me! Change me!" Do it now before it grenades. IRONDOG

 

[Zenith]

Irondog -
This is a friends bike which he sent down to a good local mechanic recently, while servicing other parts of the bike he threw in this second hand piston(8-10 hours supposedly) because my friend doesn't exactly run the bike hard. He took the bike out to a very muddy practice day, didn;t notice any noise, if it was there. Then he started during the week and this noise was there.:think
He has a Wiseco kit but was not planning on putting it in until July/August time...
It's hard to say, maybe he should just put in the Wiseco now, it would probably last for well over a year at his current rding level...

Thanks, I was always wondering what piston slap sounded like!;)

 

[k2bjarne]

Its Honda Dude

Nice to hear my old bike again. Had exactly the same problem last year, even two hours AFTER i changed to a brand new piston. But all my other honda-riders had the same sound. Then one day when was about to clean my carburator, I noticed something. The reeds were loose and slappy. I`d got some new floating around so i but them on. Brand new one from Boyesen. Stiffer and with better flow. And then, the sound was almost gone!

Try it. It did get better power also!

Boyesen Reeds, And new Piston and you get yourselves a stealth-bike

 

[georgieboy]

nice sound, but to me it sounds like gearing. I have a husky with this kind of sound and i blame my primary gears. I just put in a new set of crankbearings and because of that i of course had to disable the whole engine. Now my gears even make more sound. I also put in a new piston, so piston slap for me is a no way.
The thing is i have a lot of freeplay(backlash)between the the primary gears, about 0.15mm, 0.05mm wld be normall i think, and this causing a lot of noise.
So it cld be that yr crankbearings are gone causing more freeplay at the primary gears, You can check this by grapping the flywheel and give it a toss.
You may feel some up and down movement(there are c4 bearings used) but when in doubt let another have a feel.
Maybe you are low on oil. fill her up with oil, maximum and see whether it changes(the sound i mean) and use a thick oil.
by the way, u can measure the freeplay between piston/cilinder and see if it is still in specs.
good luck
I am getting used to my noise, so maybe u must be too.

 

[roadx]

.

 

[jmics19067]

to me it sounded nothing truly out of the ordinary just a bit tired. when he put the used piston in did it measure out ok ? did you have new rings ? did you break in the new rings proper? . I have had old bikes that sounded like that but the jug was worn with new piston in it and it would last for a bit. but if the piston is worn I wouldn't dare guess how long it woudl last

 

[Zenith]

It's not actually my bike btw...

No, we didn't measure the piston cylider clearance because I don't know how, would anybody care to explain how?

Yeah a new ring went on with the piston. Break in procedures for rings seem to vary depending on who you speak to so I don't know if they were done "right", but it was basically a few reasonably slow laps of the MX track then short cool down and then it was used as normal...

The noise leterally came over one day so I doubt it could be bearing wear although I seriously doubt main bearings were ever put into it.

I guess we'll find out when my friend eventually puts in his Wiseco kit...


Thanks,

 

[evenslower]

I think k2bjarne is right, its a Honda. Does sound a little excessive but it will still do it after you freshen up the top end. My cr250 is the same way. A new top end quiets it down for a while but its still there. Be sure to have someone who knows what they are doing measure the cylinder bore while its off the bike. Let us know how the top end affects the sound.

 

[btencate]

I have a 98 CR250 that has always sounded exactly like that even after a piston change.

 

[marcusgunby]

My clutch bearing is very noisy nowdays-sounds just like your clip-if i pull the clutch in its only half as bad.