AJS & Matchless Owners Club

Working on friends 1955 G3LS. We removed engine to strip and overhaul as required. One thing I noticed pulling it down, was the dynamo not sat right. Decided to investigate closer once the engine was back in as the lhs engine plate was wrong. Well, correct engine plate sourced and built and back in. Fitted dynamo, sprocket and chain. With the chain in correct alignment, the dynamo does not sit against the inner tin case. The dynamo has the markings as stated in both the workshop and spares books. Any ideas. The gap is about 1/4 inch

That sounds OK. So long as the sprockets are in line that will be OK. There will be a gap between dynamo and rear of the chaincase. You can make uo a seal from pipe insulation if you like but most never bother. There is a special allignment strip available or you can make one , details in Christian's archives.
Dave.

There will be a gap. The dynamo does not go up against the chain case. So if the chains are aliened that's it. 1/4" gap sounds about right. You will need quite a thin spanner, one of those flat types is what I use, to hold the dynamo sprocket, to tighten the dynamo nut. ( How would you do that if that dynamo was against the chain case? ) No there's not seal the dynamo or gearbox shaft. Guess you have no dynamo locating strip fitted. This passes through a cut out in the RK engine plate, but will stop against the LH plate. In that position chains should be aliened. Looks like Dave was typing same time as I was and mentioned location strip/ Of cause finale job is to adjust chain tension by rotating the dynamo. This may take a few goes, as when you tighten the clamping strap, it always seems to also tighten the chain a bit more.

Thank you.