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The 2-Stroke Garage => Turning Wrenches => Topic started by: RD350NL on March 09, 2025, 11:31:47 AM

Title: Piston clearance RD350B AIRCOOLED
Post by: RD350NL on March 09, 2025, 11:31:47 AM
Hi

Can someone tell me the correct piston clearance? Need to bore the cylinder to the next oversize. How much MM clearance should there be?

Thanks
Title: Re: Piston clearance RD350B AIRCOOLED
Post by: Brad-Man on March 09, 2025, 11:48:18 AM
That would depend on what brand and type of piston you use.
Title: Re: Piston clearance RD350B AIRCOOLED
Post by: RD350NL on March 09, 2025, 12:07:25 PM
Im looking to use the pistons supplied by Yambits

https://yambits.co.uk/rd350-piston-kit-100mm-p-53222.html
Title: Re: Piston clearance RD350B AIRCOOLED
Post by: 1976RD400C on March 09, 2025, 12:35:25 PM
The factory manual says .04mm (.0016") but .05mm (.002") adds a little safety factor to prevent seizures. Bore it to a size that will allow the last .002" be done with a good hone to remove the bore tool fracture marks and be left with a good surface.
Title: Re: Piston clearance RD350B AIRCOOLED
Post by: m in sc on March 09, 2025, 08:04:02 PM
.002 is fine on those. the clearance is on the box usually.
Title: Re: Piston clearance RD350B AIRCOOLED
Post by: irk_miller on March 10, 2025, 08:44:32 AM
I send the jugs with the pistons to the machine shop and everything comes back ready to install with clearances already sorted.