Tappet Adjustment spanner size

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Joined: Sun Oct 11, 2009 6:48 pm

Tappet Adjustment spanner size

Unread post by star15 » Mon Oct 20, 2014 6:24 pm

Do you know the size of the square on the top of the tappet adjuster, is there a Whitworth or AF spanner that will fit ?, are they all the same size ?, or do they differ from bike to bike, this is the square part, not the lock nut.
Last edited by star15 on Tue Oct 21, 2014 9:09 pm, edited 1 time in total.

Pete R
Posts: 81
Joined: Sat Jul 07, 2012 8:04 am

Re: Tappet spanner size

Unread post by Pete R » Tue Oct 21, 2014 2:21 am

I think anyone would have to know what bike you're working on, before they could give you an answer.
For clarity, the tappet is the cam-follower. I think you're talking about the the valve adjustment screw on the rocker arm. Correct me if I'm wrong.

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Joined: Tue Jul 14, 2009 9:52 am

Re: Tappet Adjustment spanner size

Unread post by trophy » Wed Oct 22, 2014 2:22 pm

5.5 metric open ended or 5/16 af ring fit mine.

Posts: 539
Joined: Wed Sep 23, 2009 11:52 am

Re: Tappet Adjustment spanner size

Unread post by DAVE M2 » Wed Oct 22, 2014 4:44 pm

or if it's a triumph buy the combined adjuster/clutch driver that was supplied with the bike

Rick Parkington
Posts: 514
Joined: Mon Feb 23, 2009 1:21 am

Re: Tappet Adjustment spanner size

Unread post by Rick Parkington » Sat Oct 25, 2014 11:37 pm

I find a 4BA open ender works okay for most 5/16 tappet adjusters and you can just about get away with a radiator bleed key on 1/4 diameter ones.
Rick P

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