I am planning to mill out an exhaust port on a 750 head to weld in a fresh thread. In trying to determine the centre of the exhaust port (vertically), I noticed that the 4th fin up from the bottom seems to line up perfectly with the vertical centreline. Has any one noticed this lucky coincidence or am I wrong? This would make it relatively easy to clamp the head down in the mill, locate the centre and clean out the thread area.
Is there not enough metal…
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It was Ernie Hall, Steve M…
It was Ernie Hall, Steve Maney does a alloy threaded insert repair for £99 +vat for both sides. No welding involved
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Mick Hemmings did mine and…
Mick Hemmings did mine and welded an alloy insert in, the first repair which was a bronze insert shrunk in became loose.
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Unfortunately there is no…
Unfortunately there is no budget for paying a professional to do this job. I am trying to break the job down into simple enough steps that I have the skill to do. This includes very basic lathe work, mill work and welding. Both ports had welded-in inserts already and one has stripped for at least the 3rd time. At least I know how to prevent them stripping or rattling loose ever again.
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Is there not enough metal in there to do a helicoil repair? I had mine helicoiled 38 years ago as recommended by Norton themselves and it's worked fine. I can tighten my exhaust nuts with gay abandon. I would be reluctant to carry out any welding repair if I could avoid it as the localised heat and distortion would require further attention. The guy who did it was in Croyden and used to feature in MCM tuning a 500 aircooled Suzuki, Ernie or Eddie .......Hall maybe?.......... seems to ring a bell but it was 38 years ago I suppose he had the giant tap and inserts to do the job.