AJS & Matchless Owners Club

Hi, I am overhauling the cylinder head of my 1949 AJS model 18. Amazingly the valves and guides are in perfect condition after a clean up. But due to the head being off for years and the exhaust valve being stuck slightly open there was some corrosion on the valve seat. I have spent hours grinding in the exhaust valve but there is one tiny spot on the seat that I can not seem to get out. Can anyone recommend a seat cutter that works. I am loath to buy one of these Chinese made kits that will probably be softer than the seat. Alternatively can anyone recommend anywhere in Kent that I could get this seat re cut as it will be far cheaper than buying a set of seat cutters. Thanks.

The old bikes are not that fussy. Its just one tiny spot. If the seat is re cut the angle may not match to how the valve has been ground.
I would not worry about one small spot that shows up after grinding. You will probably find the bike would not worry either.

I purchased one of the ebay valve seat cutters from India , spot on it works well and has been used on at least half a dozen cylinder heads with no problem usually after replacing valve guides on my Norton 750's ( opps matchless ! ) and a few matchless singles

I'm with Rob on this. One little bit of pitting won't hurt. The last thing you want is a too deeply cut/recessed seat.

It depends what you call a tiny spot. If you have a line of 'nicely' ground seat of at least one or one and a half millimetres preferably on the exhaust port edge then unless you start racing the bike you should not have a problem. As 1608 says grinding away a seat too much can be a worse problem

I agree with avoiding " pocketing " the seats. Also in leaving well alone. I have known so many people that have fitted new valves, guides and seats. Then get problems with valves sticking, guides coming loose and seats turning.