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+--- Thread: Starter Dog Threads (/showthread.php?tid=7627)
Starter Dog Threads - Wilfred Cawley - 17-06-2022
Hello. Ive foolishly started fixing my fathers chummy and the problem is that the starter dog nut won’t go into the threads on the end of the crank. The reason this has happened is because the threads removed themselves from the nut and have welded themselves into the end of the crank. I have since found the correct taps but they don’t seem to be taking to the cranks. Is this because I have a phoenix crank that has been hardened? Do I need HSS taps? Is the hole now to small? Oo forgot to mention, it’s a mag engine. Any help would be appreciated. Cheers.
RE: Starter Dog Threads - Adrian Payne - 17-06-2022
Hello Wilfred
To the best of my knowledge the thread is a non standard 5/8 x 16 Whitform so not BSF. If you have the correct tap it should clean out the thread of a hardened crank.
However, I have had a Phoenix crank in the past that had an under size thread in the nose. I had to screwcut the starter dog under size to get it to fit.
Hope that helps.
Adrian.
RE: Starter Dog Threads - Ruairidh Dunford - 17-06-2022
Mag starter dogs need to be altered to fit into a Phoenix crankshaft.
You need to waste the threads nearest the front.
RE: Starter Dog Threads - Tony Griffiths - 17-06-2022
Is only a little reduction in diameter necessary? Might running a thread chaser of the right pitch and angle (55 degrees) up and down the starter dog thread work? You'd need a lathe of course to do the job. https://www.ebay.co.uk/itm/361933697232
RE: Starter Dog Threads - Ruairidh Dunford - 17-06-2022
E39E9522-87C0-40FB-B7A8-BCF737999B4A_1_105_c.jpeg (Size: 73.44 KB / Downloads: 246)
598EE2EC-521D-4656-8852-9E54D648FE22_1_105_c.jpeg (Size: 78.28 KB / Downloads: 247)
RE: Starter Dog Threads - Tony Griffiths - 18-06-2022
A perfect explanation with all the essential pictures. Thanks you for taking the time and trouble to post.
RE: Starter Dog Threads - Ruairidh Dunford - 20-06-2022
I hear you Tony,
