Piston Wear

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Piston Wear

Postby Lisastec » Tue Nov 09, 2021 7:56 pm

Is this piston wear normal? The marks are on both sides.
Thanks for any help!
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Lisastec
 
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Re: Piston Wear

Postby Mutt » Tue Nov 09, 2021 8:04 pm

Ive seen a hundred like that
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Re: Piston Wear

Postby Lisastec » Sat Nov 13, 2021 9:48 am

So how bad is it? There are marks on both sides.
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Re: Piston Wear

Postby Mutt » Sat Nov 13, 2021 10:05 am

Most likely the air cleaner wasnt doing it's job. Dirt in the air fuel mixture coming up thru the transfer ports and getting on teh cylinder walls with the piston going up and down works like sand paper.
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Re: Piston Wear

Postby Lisastec » Sat Nov 13, 2021 5:34 pm

Thanks!
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Re: Piston Wear

Postby 250_Sprint » Sat Nov 13, 2021 8:26 pm

So your question is probably, ‘Is this usable?’
I am from camp, WILL THIS FUNCTION AS IS, FOR MY PURPOSE? Or does it need replacement?
With the cylinder and piston cleaned up, and a new set of rings, will compression be within specification?
Is the piston pin within specification?
It all may clean up and be within spec. with time and new rings as the only investment.
Of course, if your intended use requires more than a set of rings, then service the cylinder, new piston, new rings, new piston pin bearing and compression should be factory fresh.

I stumbled upon a 1948 motorcycle with a parts from a variety of years for a fair price. I did get the engine to run several times even though the generator bearing on the crank had considerable play.
I have cleaned the cases, replaced all bearings and gaskets and it was not difficult. I took my time. I took measurements before taking apart, bagged and tagged and didn’t lose a part, or have left-over parts.
She runs good and responds well.

So what you have may suit your needs. It may just need cleaning and rings.
Last edited by 250_Sprint on Tue Aug 16, 2022 10:01 am, edited 2 times in total.
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Re: Piston Wear

Postby Lisastec » Sun Nov 28, 2021 3:45 pm

Thanks for your info! The reason we took it apart was that it would start and not stay running or start when hot. All carburetor adjustments didn't help, compression was inconsistent, checked all the other easy fixes with no improvement. I have a new piston, rings and gasket that will be my winter project.
How much side to side motion should the connecting rod have?
Thanks for your advice!
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Re: Piston Wear

Postby Mutt » Sun Nov 28, 2021 4:44 pm

1/16" each side is maximum. Your seals are shot, probably the original 60 year old seals. I have all engine rebuild supplies in stock if ya cant find them
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Re: Piston Wear

Postby 250_Sprint » Tue Aug 16, 2022 10:04 am

Do you have an update?
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