'63 r60 losing power after warmed up

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Slash2
Posts: 339
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Re: '63 r60 losing power after warmed up

Post by Slash2 »

Ziggy,

I took today to do a little diagnostic and go ahead and do the tear down, rebuild of the mag body. I replaced the plug wires which incidentally were only a few months old. I had sourced them from Vech and they were shorter than I like them to be but that’s another story.
At any rate, I tore the mag body down, used 400 sand paper to clean the mating surfaces, tapped and chases all threads and then reassembled with no-ox.

No need to remove the mag rotor provided it’s indexed correctly. I rebuilt the body on the bench and bolted it up. Set the points gap, static timing and fired up the bike for dynamic. As usual it started fine and ran predictably well. At this point the Sun had set and it was getting cold so I replaced the worn throttle cables and and took a spin around the driveway.

I’ll go out and really put this work to the test tomorrow and report back. The only curiosity that I’m pondering here this evening is that the left side plug wire was intermittently sparking at the coil. Perhaps 2 to 3 times per minute.
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64' R60/2 - 66' R27 - 51' R67 - 68' R69S
88' R100RS - 06' K12R

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wa1nca
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Location: Ashfield Ma

Re: '63 r60 losing power after warmed up

Post by wa1nca »

Any sparking at the safety gap is not good and would certainly get worse under load and at a higher rpm
It is usually caused by a bad plug wire or plug cap which you said have already been replaced?
check that the gap is at least 10mm and the the plug wire on the coil is not to long coming out of the bottom of the coil terminal decreasing the gap
Tommy
Tommy Byrnes
54 R51/3 55 R50/Velorex 560 sidecar 64 R27 68 R69US
Ashfield, Ma
USA

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Slash2
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Re: '63 r60 losing power after warmed up

Post by Slash2 »

wa1nca wrote:
Sat Nov 14, 2020 9:13 am
Any sparking at the safety gap is not good and would certainly get worse under load and at a higher rpm
It is usually caused by a bad plug wire or plug cap which you said have already been replaced?
check that the gap is at least 10mm and the the plug wire on the coil is not to long coming out of the bottom of the coil terminal decreasing the gap
Tommy
Thanks Tommy. I'll check those items you mentioned. The safety gaps are both set to about 11mm. The wires are new and the caps are the brown bakelite BMW units available from Vech and others.

Ziggy,

After performing all the work mentioned, I took the bike out yesterday for 30 trouble free miles. This was at least a major step in the right direction. After reading a bit more of the Barrington Book I also retarded the idle speed timing a bit to help starting and in doing so brought the slightly advanced at speed timing back to the mark. Placebo aside the bike seemed more willing to start and ran better than she has yet.

Have you given thought to your next move here?
64' R60/2 - 66' R27 - 51' R67 - 68' R69S
88' R100RS - 06' K12R

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wa1nca
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Location: Ashfield Ma

Re: '63 r60 losing power after warmed up

Post by wa1nca »

Slash2 wrote:
Sun Nov 15, 2020 10:45 am
wa1nca wrote:
Sat Nov 14, 2020 9:13 am
Any sparking at the safety gap is not good and would certainly get worse under load and at a higher rpm
It is usually caused by a bad plug wire or plug cap which you said have already been replaced?
check that the gap is at least 10mm and the the plug wire on the coil is not to long coming out of the bottom of the coil terminal decreasing the gap
Tommy
Thanks Tommy. I'll check those items you mentioned. The safety gaps are both set to about 11mm. The wires are new and the caps are the brown bakelite BMW units available from Vech and others.

Ziggy,

After performing all the work mentioned, I took the bike out yesterday for 30 trouble free miles. This was at least a major step in the right direction. After reading a bit more of the Barrington Book I also retarded the idle speed timing a bit to help starting and in doing so brought the slightly advanced at speed timing back to the mark. Placebo aside the bike seemed more willing to start and ran better than she has yet.

Have you given thought to your next move here?
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By Peter Ardron
Tommy Byrnes
54 R51/3 55 R50/Velorex 560 sidecar 64 R27 68 R69US
Ashfield, Ma
USA

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schrader7032
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Re: '63 r60 losing power after warmed up

Post by schrader7032 »

And just to be sure I understand, Tommy, the distance is from the very end of the spark plug wire, not the terminal, right?

Wow, that's a nice shellac covering on that coil! :D
Kurt in S.A.
'78 R100/7 '69 R69S '52 R25/2

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wa1nca
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Re: '63 r60 losing power after warmed up

Post by wa1nca »

Yes the spark will take the shortest path to ground
I always insert or trim the plug wire not to exceed the bottom of the coil terminal
So the picture I posted with the coil wire inserted past the bottom of the coil terminal would make the gap less than 10mm
Tommy
Tommy Byrnes
54 R51/3 55 R50/Velorex 560 sidecar 64 R27 68 R69US
Ashfield, Ma
USA

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Slash2
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Re: '63 r60 losing power after warmed up

Post by Slash2 »

Tommy,

Is that one of the new reproduction original style coils? I purchased one of those a few months ago and while the stock photo looked like yours, heavily shellacked, the one I received was missing the shellac and ended up producing a weak intermittent spark. I returned that unit and sourced an Emerald Isle which seems to function much better.

In your photo, the lobes on your advance unit appear to be set up off balance with one side particularly loose. According to Vech, it is important to preload those advance springs. Otherwise I would imagine you’d have a less than ideal throttle response.

I pulled my engine cover today and as you said, pulled the wire up flush with the terminal. This seems to have fixed the sparking issue though she did spark repeatedly while initially kicking the bike at start up. Is this normal or should I consider replacing these new caps?

Thanks.

Ziggy,

Sorry to hijack your thread. We’ll return to your topic as soon as you return with an update.

Thanks!

Chris
64' R60/2 - 66' R27 - 51' R67 - 68' R69S
88' R100RS - 06' K12R

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Ziggy
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Location: Massachusetts

Re: '63 r60 losing power after warmed up

Post by Ziggy »

Finally, a turn the corner day! After taking time to refurbish the advance mechanism, recheck the points gap, re-time ignition and also unfasten and re-fasten the new Emerald Isle coil, took the bike out today and had a problem free 30 miles. I am almost in disbelief. Was it the advance, or a bad ground, or a combination of the two? No matter what, everyone's input here definitely was part of getting it back on track so thank you!

More work to do, but to be able to get more than 10 minutes of trouble free riding and not limp home was a great leap forward, especially in 40 degree temps and overcast skies!

Slash2, sounds like you too are on the right track, which is great.
JF Rogers
'63 r60/2
Scituate, MA

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Slash2
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Re: '63 r60 losing power after warmed up

Post by Slash2 »

Great news! Glad to hear you’ve made a break through. Do you have any general feeling which of those issues may have been responsible for the improvement?
64' R60/2 - 66' R27 - 51' R67 - 68' R69S
88' R100RS - 06' K12R

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Ziggy
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Location: Massachusetts

Re: '63 r60 losing power after warmed up

Post by Ziggy »

My gut says bad ground, but the advance did get new springs (which got me using a jeweler's magnifying visor and dental tools and a whole lot of patience!) I also swapped out weights taken from an old advance. The original weights had become out of round on the pivot points from wear. I wanted the aha! moment, to be sure whatever was not correct had been fixed, but after 6 weeks of chasing the problem, I'll take it being rideable again.
JF Rogers
'63 r60/2
Scituate, MA

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