Exhaust guide

Discussion in 'Honda Cub Showcase' started by Alaus24, Feb 2, 2020.

  1. Alaus24

    Alaus24 New Member

    Dec 28, 2019
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    I was given an 84 c70 passport . Canadian version. It has a bent exhaust valve. I saw 1 video with it being repaired. The guy used a 2 part mix that he put on the guide before inserting? Also the exploded diagram i have shows an Arai o ring under the guide. Anyone ever replace one?

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  3. racerx

    racerx Administrator
    Staff Member Administrator

    Jul 10, 2005
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    Valve guide replacement is no big deal with any of these heads. It's a $20-35 job, farmed-out. The old guide is pressed out, the new replacement pressed in then finish-reamed & honed. All that's needed is a new guide + seal (a specialized O-ring)...and the OEM tools. Then, it should take nothing more than a valve job (using new valves)...voila! good as new, ready for the next 36 years.

    That said, as long as you can loosen the bent valve enough to spin it inside the existing guide, then pull & twist it free using Vise Grips, chances are very good that the guide will survive and need nothing more than finish-reaming. If it must be hammered out of the guide, try heating the guide (propane torch), using the opposite side valve as a drift/punch; with reasonable care and a little luck, the guide won't have to be replaced.

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