New(ish) owner intro

[mfennell]

Just joined a few days ago from NJ, USA. I won a cafe'd '72 Commando on a whim bid at Iconic Auctions back in January. It was previously a Cafe Racer project bike. As a project bike, it had a nice CBR front end and custom shocks. Now it has a stock front end and (I think) CB1000 shocks.

By the spec sheet, it's pretty nice. Alton starter being the best bit, but also a recent engine rebuild, a Brembo caliper conversion, nice rearsets, nice pipes, etc. The assembly is a complete trainwreck but I was expecting it to be. Maybe not quite as bad as it is but I need something to do, right?

In truth, I don't know much about Nortons but there are NINE of them in the shop I share with a couple friends. Both agree - solid hard parts, indifferent assembly, some really dumb sh*t.

It runs quite well but I fouled the plugs and (foolishly) cranked the hell out of it until it now sounds like I've messed up the sprag clutch. Because I am dumb and didn't realize I should be worried about that. It leaks a shocking amount of oil from the primary cover so I need to get in there anyway. I just finished a couple other projects (helpful hint: don't by new bikes from Piaggio Group) and it's time to put the Commando on the lift.

Hmmm..I'm not seeing a way to upload pics, so here's a link to the Iconic auction: https://iconicmotorbikeauctions.com/auction/1974-norton-commando-850-2/ and a pic from it.

 

[Richard Tool]

PM sent

 

[mfennell]

I can't reply yet. Middletown.

 

[ashman]

Looks like its got some good upgrades too it, make sure it hasn't wet sumped as starting it with a full crank case of oil could blow out the left side crank seal and fill up the primary case, run ATF in the primary case with no more than 7 floz of oil for the chain lube, its had a bit of money spent on it so get to know your Norton and learn the little faults they can have.
Good buy and enjoy.

Ashley

 

[Tornado]

To post pics directly, you need to be VIP member.

The commando does tend to wetsump if not run in weeks/months. Running an electric leg or starting up with meat leg when moderately wet sumped puts high loads on the starter and can also lead to crank oil seal blow out into primary side...making primary fill with oil and leaking out at the gb sprocket opening.

So if sat more than a few days, best to check/drain the sump prior to starting until you know how severe your engine does this. Afterva good 20 min run, check oil in tank level, then compare it at next pre start up day...any significant drop, do not top up until you drain sump first...otherwise risk overflowing tank out breather as excess sump oil is pumped back.

 

[DennisMo]

I have an Alton too on my 73 850. You say you may have messed the sprag. It may be that you have instead sheared the internal plastic dowels that protect the Alton from kickback.

The Alton internal plastic dowels protect the starter motor from kickbacks as they can destroy the motor. The idea is that they shear first and protect the starter motor. You then pull apart and replace them.

Very important is to have an electronic ignition that, under 500 rpm, has ATDC timing. The TriSpark has this.
If you have ATDC spark under 500 rpm, you will not shear the plastic dowels.

If you do pull it apart and inspect, do keep into touch on forum or by private message.

Dennis

 

[mfennell]

Thanks for all the tips. Regarding the wetsump issue, I forgot to mention that the bike has an NYC Norton anti-sumping valve. My friends had warned me as well (one had been a victim, in fact) but I gather that the NYC Norton part protects me here.

I'm hoping the shear pins are my starter problem but I won't know until I poke my head in there. I forget what ignition it has.

I'll be sure to post pics as I dig in. While the bones are there, there's a LOT wrong with the bike. I would have been embarrassed to sell it as it is but here we are. I was actually enthusiastic about subscribing to Cafe Racer magazine until I started going over the bike. Now the idea of giving them money pisses me off.

 

[gortnipper]

The

I forgot to mention that the bike has an NYC Norton anti-sumping valve. My friends had warned me as well (one had been a victim, in fact) but I gather that the NYC Norton part protects me here.

Do you mean this?

If so, that is the best crankcase breather but not an anti-sumping valve.

I don't think Kenny makes an anti-sump valve and I don't see one in the pic.

 

[gortnipper]

They usually look like this

Google Image Result for https://www.accessnorton.com/attachments/dbffb97b-4644-4647-915c-2eb4f128d376-webp.81057/

Or

Google Image Result for https://www.nortonownersclub.org/sites/default/files/2024-02/RGM%20anti%20wet%20sup%20valve.jpg