bsr65
High Number
Posts: 114
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Post by bsr65 on Feb 20, 2014 9:53:41 GMT
after a rebore on a standard p200e barrel is it recommended to chamfer the ports.
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Post by sbwnik on Feb 20, 2014 22:28:56 GMT
I never have, but a quick once over with the file may not hurt. The hone should take off any burrs.
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bsr65
High Number
Posts: 114
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Post by bsr65 on Feb 21, 2014 15:26:02 GMT
cheers Nik, good advice as usual.
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Post by kru251 on Feb 21, 2014 22:07:23 GMT
I always do with a new barrel or a re-bore. Just a light touch with a needle file to take off the possible raised/sharp port edges that could easily snag the rings in the initial stages of running in.
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Post by pxguru on Feb 22, 2014 8:58:18 GMT
Ideally ports should be chamfered top and bottom at a shallower angle (like 30 degrees). this is to stop the rings catching in the port and to not scrape the 2 stroke oil off the piston. No need to chamfer the sides so much but top and bottom should be about 1mm chamfer. The ports in the piston should be chamfered the same way too. If you have trouble with heat seizing and the marks are above a port this will help a little.
btw, don't do this yourelf on an ally barrel just the iron ones!
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Post by joey on Feb 23, 2014 9:30:09 GMT
Surely if it was an alloy barrel he wouldn't be asking the question???
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Post by partanen on Mar 1, 2014 10:48:50 GMT
I'd like to know why not to chamfer alloy barrel? Does it ruin the nicasil coating or why is that?
Scooterwest recommend to do so for Malossi barrel, which is made of alloy.
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Post by joey on Mar 2, 2014 23:36:15 GMT
If you try to chamfer nicasil with anything other than a VERY high speed tool you'll flake the coating and goose the barrel.
Rule of thumb on iron barrels is to rub your thumb over port edge (top and bottom,) if it feels sharp give it a wazz with a dremel just to blunt the edge, Polini being a classic when new, but sometimes the Malossi 166 has the same problem.
Don't worry too much about angles or depths just take the sharp edge off.
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Post by partanen on Mar 3, 2014 11:49:39 GMT
I see. Thanks.
Dremel maybe?
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