Seeking MK3 backfire device adjustment help

[Larry Kahn]

After doing all the upgrades to re-fit the starter assembly for my 71 yo knee all worked great for a few rides but now the backfire device just spins even with the spark plugs out. Read all the old postings here on the unit and tool needed setting these up feels beyond my mechanical aptitude. Old Britts has retired and CNW does not mess with these. New from Andover Norton will end up being @$400 or so for a complete assembly. Any shops or individuals experienced with these out there willing to check mine and adjust? Or willing to loan the home-made tool needed? I'm in California.

 

[kommando]

Read

C

Thread 'Mklll Anti Backfire Device Adjustment'

Dec 10, 2014

Looking for comments on adjusting the AB device.

I know it requires 50 ft-lbs torque setting. I made the special tool with socket and thrust washer, per Old Britts.

Questions:
Does the AB device turn clockwise when testing slip?

If slip is less than 50 lbs torque, is AB device slip "tightened" with the large nut on the disk spring side?

How do you keep that nut from loosening?

What is the consequence of slip at less than 50 ft-lbs torque?

• chasesa
• Replies: 5
• Forum: Norton Commando Forum

Why worry?? Sent the AB unit to Fred Eaton to adjust.
$65 plus shipping each way

 

[L.A.B.]

Old Britts, Overload backfire device assembly and adjustment

 

[Larry Kahn]

Old Britts, Overload backfire device assembly and adjustment

Thanks, have seen that but not with the pictures.

 

[L.A.B.]

I set mine with a socket and some lengths of welding rod instead of making a tool.

 

[nortonmargie]

Where in California are you? PM me.

 

[Torontonian]

71 ? Yo knee ? Oh , you are 71 and the knee you are worried about hurtin' . ?
Mine has never engaged or slipped . If it did I would give it to Geoff Doherty in P.E.C. , Ontario .
I never kick the MK 3 .