Just in the process of replacing the magneto chain on my 1935 Es2. I found that the chain fitted was a 44 link chain and was very slack. Checking this out I discover it should be a 42 link with 15 tooth sprockets. I have 15 tooth sprockets fitted. Despite moving the mag as far forward as possible, the chain is bar tight. I have checked every possible measurement on both chains and they are exactly the same size. On the Racing Norton site he supplies a half link for the chain explaining that on some cases it seems that the chain is either to tight or to loose and the correct length chain just won't adjust properly. I don't really want to fit a half link until this can be confirmed by a club member. Or am I missing something? Thanks in advance.
How about trying a new 44 link chain and new sprockets? This will probably take up some if not all of the play. Adding half-links into any chain will solve one issue but possibly cause a whole bundle of others.
Thanks for your thoughts Phillip. The sprockets look in very good condition. The 44 L cgain was so loose it was possible for it to almost reach itself if pulling together when attached. The point is why does it state it should be 42L with 15t sprockets but is still bar tight? The 44L goes with the 16t sprockets which it would need to be as sprockets are bigger. Any more ideas most welcome.
What is it that is stopping the magneto from moving further forwards ? Is the base plate physically touching the crankcase or does the problem lie with the slots ?
Thanks for your response Richard. The platform is very close, but not touching the crankcase. As you would know you cant see the whole slot but it would seem it is at its full travel. Just as a further observation, the sprocket on the mag gets caught on its threads when trying to put it on where the chain is so tight. The odd thing is how ridiculously loose the 44 l chain I took off was, with as I said all of the mag adjustment taken up to tighten it compared with high tight the correct 42l one is on the other end of the Adjustment. Totally baffled to be truthful.
I've been scratching my head too. I only have direct experience of the open diamond frames which have different engine plates but the principle is the same. Could it be that the mag platform has fretted into the engine plates ? Have you slackened everything right off ? If there is a wear ridge on the plates and they're not loose enough, I can imagine that they'd block. If so, it may be difficult to adjust without rectifying the plates. Photo below shows my 16H during assembly with standard 15t and 42 link...No problem at all in obtaining free-play.