Dead dynamo

[Minto]

So I think it's been on the way out since I bought the bike, ( intermittent charging or no charge showing on ameter) but now seems to have given up all together. I removed it from the bike and took it to local garage's auto electrician who is of the appropriate vintage to understand these things. Says the armature is gone. When funds allow (parts for my other bike are taking president at the moment as I anticipate having to use it for commuting soon) I'll get it sent to Andrew at Priory Magnetos, but in the meantime I plan on running it with the dyno drive chain removed and just recharge the battery as and when required.
Is there anything I'm missing or is it just a case of replacing the dyno and just removing the chain so it doesn't get spun?
Thanks all
Jase

[RichardL]

Why not remove the whole dyno, temporarily, instead of just the chain? There's no path to flowing oil in the dyno side of the timing cover. If you go this route, you should probably remove the strap and strap stud, as well, so they don't shake all over the place and get lost.

Richard L.

[muskrat]

G'day Minto.
I agree with Richard. Just make up something to plug the hole in the inner timing cover. Leave the large driving sprocket on to take care of end float of the idler gear shaft.
Cheers

[Minto]

Good call Richard and Musky, I did think about that but the hole will need to be blanked to stop crap getting in. I've seen a few trials type A10s without dynamos but never got a good look at how this has been blanked.

[RichardL]

Well, I was about to say, "who cares about a little dirt among the grease," but then thought about the damage a pebble could do jammed against the sprocket.

Richard L.

[Rex]

I would say leave the dynamo in place as it fits the hole perfectly, and you won't lose the various bits and pieces over the months. 

[berger]

Minto you could make an ally plate as i did for mine when i ran it without the dynamo.

[CheeserBeezer]

So I think it's been on the way out since I bought the bike, ( intermittent charging or no charge showing on ameter) but now seems to have given up all together. I removed it from the bike and took it to local garage's auto electrician who is of the appropriate vintage to understand these things. Says the armature is gone. When funds allow (parts for my other bike are taking president at the moment as I anticipate having to use it for commuting soon) I'll get it sent to Andrew at Priory Magnetos, but in the meantime I plan on running it with the dyno drive chain removed and just recharge the battery as and when required.
Is there anything I'm missing or is it just a case of replacing the dyno and just removing the chain so it doesn't get spun?
Thanks all
Jase

I have some second hand dynamos in my personal stock if you want a cheap solution. £120 with a six month guarantee. Alternatively we can do a proper job through the business. Thanks. Andrew

[RichardL]

I would say leave the dynamo in place as it fits the hole perfectly, and you won't lose the various bits and pieces over the months. 

I wouldn't argue with this logic, either, except removal allows it to be sent for service.

Richard L.

[Rex]

True enough.
I bought a small alloy blanking plate for a Triumph 650 from the US in the early days of Ebay. Apparently it was OE for the bikes not running dynamos, though I never saw one for sale this side of the Big Pond.

[muskrat]

G'day Rex.
Is this the one ?
https://tinyurl.com/2sa6pmjz Trihard part # 70-2784
I can't see how it would work on our A's.
A few in Au, US, Canada but can't see any in UK.
Cheers

[Rex]

Looks like it. Meant for all those desert sleds etc I suppose which were a bit thin on the ground here.
Maybe BSA's used something similar when they were shipped to the Dry States for off-road bikes?

[Minto]

CheeserBeezer
PM sent.

[Minto]

Thanks CheezerBeezer, fantastic service. Can't believe how fast that arrived, less than 24 hrs from ordering to delivery. Amazing!
Cheers

[Greybeard]

I made a simple cover for my bike once when I needed to get the dynamo repaired. I used some wood inside the case and used wood screws through a plate made of alluminium.