Ragged piston to fuck?

[fast_tzr]

As title really....is it knackered?

[Pete.]

Whatever you took the photo with is
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a.k.a 'Geri'

132.9mph off and walked away. Gear is good, gear is good, gear is very very good

[fast_tzr]

Yeah, dodgy phone....so, can it still be used?

[Blau Zedong]

I would say it's got excessive blowby. What's that shit on the crown??? Is it a crater or just carbon? You need to have a measure of the clearances / ring gaps etc.
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18:54:48 Rob Fzs: jews don't give away stuff for free

18:54:59 Rob Fzs: unless its their clothes/ hair/ golden teeth

[lukamon]

blowby = ragged and / or high mileage.

new piston and rings.
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killa wrote: Im an ass man myself

[fast_tzr]

Only carbon on the crown, I can't understand why there would be any blow by, the bikes only done 5000km odd from new.

[lukamon]

that looks like a 50cc....

when 2t engines are revved too hard the rings "skate" rather than seal, against the bore so you get blow - by. doesnt matter about mileage really.
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killa wrote: Im an ass man myself

[fast_tzr]

Yeah it's a 50, I haven't even ragged it all that hard, warmed up most of the time, hasn't gone much past 11k rpm, and I know plenty of people who've revved their bikes beyond that for more miles.

[lukamon]

it doesnt mean the engine is screwed, after all, you probably didnt notice a lack of compression till you took it apart? blow - by will not kill an engine as such, but you should replace damaged parts upon rebiulding.....
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killa wrote: Im an ass man myself

[Jamie S]

And you are not allowed an animated avatar but you have one.

Get rid of it.


As for the piston , buy a new piston , rings and little end.

[fast_tzr]

Yeah loss of compression wasn't really an issue in the first place, I took the top end off for something different.

Main point being, can I get away with using it for any longer? Can't really afford a new piston atm.

[Pete.]

Excessive blowby is caused by worn rings not piston (although it can aggravate it) so you could clean up the piston and fit new rings.
____________________
a.k.a 'Geri'

132.9mph off and walked away. Gear is good, gear is good, gear is very very good

[fast_tzr]

I really still don't understand why the rings would be excessively worn though, the bikes done under 5000km and hasn't been massively over-revved.

[Pete.]

Could be down to using cheap 2-stroke oil.
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a.k.a 'Geri'

132.9mph off and walked away. Gear is good, gear is good, gear is very very good

[fast_tzr]

Oil was fairly good, Spanish brand, fully synthetic.

[Walloper]

Going by the photo...... Yes it's Fahcked.

C'mon man. Pick your game up a bit.

We're all purfeshonalls on here..

Can't say from pic.

The ring grooves are most critical.

The pin bore.

Any deep scoring around the skirt.

Put a scabby piston in the engine is never recomended.
It's flying up and down at 5000000 times a second.
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W-ireless A-rtificial L-ifeform L-imited to O-bservation P-eacekeeping and E-fficient R-epair

[lukamon]

im not alloed animated avatars?
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killa wrote: Im an ass man myself

[Jamie S]

No you are not.

[bugsy46]

who are you the forums second in command?
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Laura - "And where did looks come into this and bugsy leave steven alone. You are not gods gift to women you may think you are but you're not."
Keith - "All the best"

[cheekythomas]

Looks like it... but does that matter... says no animations so he is within his rights to point it out

Back to the topic... Yes that piston is dead. Is it worth putting it all back together with new gaskets etc, when you know its dead and will have to do it again soon anyway?

What bike is it?? Looks like a minerelli piston... if so i might have one

[Welshd1k]

[fast_tzr]

[Chriss]

[Pete.]

If the piston isn't scored there's no reason why it cannot be re-used. There doesn't look to be any wear-marks even.

Remove the rings (carefully) and put them in the bore from the bottom one at a time. Push them up the bore using the piston skirt until they are near the top. If the end-gap is huge the rings are worn out and need to be replaced. I would have no problem re-using that piston if I was tight for cash it looks like it has plenty of miles in it yet.
____________________
a.k.a 'Geri'

132.9mph off and walked away. Gear is good, gear is good, gear is very very good

[Walloper]