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Old 06 October 2014, 15:12   #1
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Honing a 2S

Today I took the block of my Yamaha 30 into a large local engine machining shop, asking for the (steel) bores to be honed. They told me they couldn't do two-stroke engines as their honing equipment "ate the ports". This seemed a little odd - is this typical or were they just fobbing me off?
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Old 06 October 2014, 15:28   #2
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honing the cylinders may alter the port timing
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Old 06 October 2014, 15:39   #3
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Two strokes are difficult to hone as the tool tries to drop into the ports.many shops use a tool with stones on wires kind of like a wire brush but with stones on the end of the wires. These will damage the ports
You need a tool that uses 3 flat stones & use a slow speed drill to hone the bores .
You still need to be careful that the ends of the stones don't drop into the ports
You might be better going to somewhere that does motorbike engines if you don't want to do it yourself

something like this you need

http://www.ebay.co.uk/itm/DRAPER-CYL...item4d1cff4c48
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Old 06 October 2014, 15:57   #4
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thats the tool (in the link Not beamishken )

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Old 07 October 2014, 04:24   #5
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Thanks. I did consider one of the honing tools in the link - it should be self-centering after all.

Found an old guy (with a biro-laden brown shop-coat) who seems to know what he's doing.
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Old 07 October 2014, 08:23   #6
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Dont forget to use a bit of fine wet and dry around the ports, to make sure there are no burrs, that will chew the piston or its rings.
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Old 07 October 2014, 11:20   #7
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Quote:
Originally Posted by uncle al View Post
Dont forget to use a bit of fine wet and dry around the ports, to make sure there are no burrs, that will chew the piston or its rings.
He'd already done it when I collected it.
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