Boyer Failure?

chasesa · Sep 11, 2014

Hi all
Is it possible for a Boyer to partially fail?

Can a bike start with a partially failed Boyer?

I am at wits end trying to get my Mk 3 to idle. Have not used it all season.

I replaced the Podtronics to no effect. Battery is fully charged (with charger). The Boyer is the last possible item...

I may revert to points, but wish to get it idling before putting it away for the season.
Cheers!
Stephen C

Rohan · Sep 11, 2014

Have you cleaned out out all the air and fuel passages for the idle circuits - in twin Amals.
And cleaned them and cleaned them and cleaned them.
Well known problem if left for fuel gunge/grange to accumulate there.
Otherwise it tries to idle on the bottom of the needle jets - ie usually rather roughly !

Assuming you have new plugs in it ?

JimC · Sep 11, 2014

Can a bike start with a partially failed Boyer?

Yes.

There are volumes posted about Boyer failures. A search will be very rewarding.

Hobot · Sep 11, 2014

MUST ALWAYS supect the trigger wires which can break inside insulation so can start and run some till vibes cut conduction or a bit longer till heat softens the insulation. ALL BETS and advice may be wasted time till this very common weakness is dealt with for sure. Otherwise Boyah black analog box may last essentially forever with its dull advanced curve response good only for poor Triumph chambers.

CanukNortonNut · Sep 11, 2014

chasesa,
Yes the boyer can still run if its damage, but not well... (Not good for the engine)...I had one fail on me. It was close to 30 years old. I sent it to Mike Partridge at Walridge Motors as he has a way to test them. He told me that my box was pre Mk111 and he had not seen those since the late 70's. The stator trigger was still good but they are not compatible with the later series boyer’s.
Can't really blame boyer after 30 years. But it was inconvenient with a ride back on a flatbed.
Thomas
CNN

Dennis C · Sep 12, 2014

What Rohan said, in talking with Fred at old Britts yesterday about my Norton under rebuild he strongly cautioned me to drain the tank and carbs if it was going to be left for any length of time or the idle would do exactly as you describe.

Dennis

boz · Sep 12, 2014

Since I only ride my Norton on short trips. Mostly to vintage bike events held on summer evenings. I only burn either Avgas or racing fuel. It has been a pleasure to not have to worry about fuel going bad and has rewarded me with a bike that I can let sit for weeks and she fires right up every time. Is it expensive yes but not so much so as chasing my tail trying to diagnose and fix problems caused by burning gas with corn in it.

hankmarx · Sep 12, 2014

I thought I had a bad Boyer, took way too much time to find a broken wire behind the headlight.

Way too much time.

Torontonian · Sep 12, 2014

Betcha idle jets clogged. :|

JimC · Sep 12, 2014

Torontonian said:
Betcha idle jets clogged. :|

90% of carburetor problems are electrical.

Boyer Failure?

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