Magneto timing

More likely to be a poorly seating float needle or a sinking float. Might be due to the rich carb touching the frame. You might find a bit of fibre between the needle and seat. If the plug was sooty due to oil, it'd probably smear and appear greasy when you wipe it with your finger. I'd be fitting #3 slides to both sides, and the recommended needles with the clip in the centre groove, and keep the jetting identical in both carbs. The recommended main jets should be OK. The only thing you usually have to play with are the needle heights unless someone has gone silly with a drill.
 
acotrel said:
More likely to be a poorly seating float needle or a sinking float. Might be due to the rich carb touching the frame. You might find a bit of fibre between the needle and seat. If the plug was sooty due to oil, it'd probably smear and appear greasy when you wipe it with your finger. I'd be fitting #3 slides to both sides, and the recommended needles with the clip in the centre groove, and keep the jetting identical in both carbs. The recommended main jets should be OK. The only thing you usually have to play with are the needle heights unless someone has gone silly with a drill.
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Thanks guys. I haven't had time to play with it but the carb that is fouling the plug is the chopped carb with no float so float level isn't the issue. My buddy was the one who tuned the carb and I noticed that the right carb pilot air screw is only a quarter turn out.... I am thinking perhaps that is a contributing factor.
 
Thanks guys. I haven't had time to play with it but the carb that is fouling the plug is the chopped carb with no float so float level isn't the issue. My buddy was the one who tuned the carb and I noticed that the right carb pilot air screw is only a quarter turn out.... I am thinking perhaps that is a contributing factor.[/quote]

1/4 turn out is very wrong,11/2 turns is about right; suggests that pilot jet is wrong size, you need to investigate& correct.
 
Bernhard said:
1/4 turn out is very wrong,11/2 turns is about right; suggests that pilot jet is wrong size, you need to investigate& correct.
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Or try winding it out further, to about where it should be, and see how that works out.
Giving it the air it needs may take away (some of) the sooting on the plug.

We sort of assumed you would have already tried this, being part of the standard tuning procedure for amals.

Its still very possible that one cylinder is running oily, however.
 
Rohan said:
Bernhard said:
1/4 turn out is very wrong,11/2 turns is about right; suggests that pilot jet is wrong size, you need to investigate& correct.
Click to expand...

Or try winding it out further, to about where it should be, and see how that works out.
Giving it the air it needs may take away (some of) the sooting on the plug.

We sort of assumed you would have already tried this, being part of the standard tuning procedure for amals.

Its still very possible that one cylinder is running oily, however.
Click to expand...

Thanks Rohan. I had 2 career motorcycle techs playing with the carbs when we got it running and I incorrectly assumed that they got that right.... You know what they say about assumptions...
 
You need to check it.
That may well be the best idle they could get out of it.
Especially if the carbs/slides are worn, and letting in extra air.

In which case, it might be some oil burning that is giving the black sooty look,
nothing to do with carburation.

??

P.S. We seem to have 2 quite similar threads running here together, hope I am sticking to the plot...
 
Well, after several hours of going through the carbs I got tired of screwing with the 50 year old Amals and decided to try out a Mikuni (I know, Blasphemy) on my Norton Altas. I bought it from Rocky Point cycles. I tell you what. I didn't so much as turn a mixture screw or swap out a jet. This carb performed flawlessly out of the box. Perfect Idle, perfect acceleration up to red line. I couldn't be happier. Well, I would have been happier with not having to buy them but they work fantasticly.

Yes, if I were going to actually race my Atlas Racer, I'd go with a beefier dual carb setup. But for cruising around town, the Mikuni will do just fine.
 
bad_friday said:
Johnnymac said:
…decided to try out a Mikuni …
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:(
Why not an Amal Premier?
Fritz
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Well, I might give those a shot in the future, but having one carb is so easy on it. Honestly, after dicking around with Amals and never getting them exactly the way I wanted them, the thought of buying more Amals was rather off-putting.
 
texasSlick said:
Good advice by johnm. I know your K2FC is NOS and should not have mis-match between cylinders, but it would be a good idea to check the point gap on each ramp. I have measured 2 degrees of timing mis-match for each 0.001 inch difference in point gap. If you do have point gap mis-match, let us know.

That said, I still think your problems are in the carbs.

Slick
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first thing to do is make sure the points are absolutely clean on the contact faces
ive never had a twin magneto that had absoloutely perfect gaps or timing , most old twins ran perfectly well with a few thou of difference

i suspect that your Nos k2f needs looked at with some one familliar with them could be ht tracking on a pick up on the bad cyl and no resistor plug caps please


your mag may have faulty windings or a duff condenser it dont matter its new the windings could be corroded at the ht /lt
.thats usualy what lets them down

try the old mag and see if it runs better
 
desmo said:
first thing to do is make sure the points are absolutely clean on the contact faces
ive never had a twin magneto that had absoloutely perfect gaps or timing , most old twins ran perfectly well with a few thou of difference

i suspect that your Nos k2f needs looked at with some one familliar with them could be ht tracking on a pick up on the bad cyl and no resistor plug caps please


your mag may have faulty windings or a duff condenser it dont matter its new the windings could be corroded at the ht /lt
.thats usualy what lets them down

try the old mag and see if it runs better
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I have seen it where the capacitor in the old mags have gone bad. Replacing them with a modern equivalent by a competent rebuilder and a rewind of the armature will make a world of difference.
John in Texas
 
N0rt0nelectr@ said:
I have seen it where the capacitor in the old mags have gone bad. Replacing them with a modern equivalent by a competent rebuilder and a rewind of the armature will make a world of difference.
John in Texas
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When the internal capacitor begins to go bad, the engine may start cold, but will not start and run hot. Time is the enemy of the original capacitors, even a NOS that has been sitting on a shelf goes bad given enough years ...... usually 30 to 40.

If one acquires an old K2F magneto, John's recommendation is Step 1.

Slick
 
marinatlas said:
if your mag need a new capacitor/condenser why not try an "easycap"
http://brightsparkmagnetos.com/
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EasyCaps seem to work fine. However, to use an EasyCap, the internal (shorted if in failure), capacitor MUST be disconnected. This requires removing the cam housing, which will likely upset the centering of the armature spindle. Few of us have the expertise and instruments to properly center the armature spindle.

Therefore, like John reply #32, I recommend a competant magneto rebuilder.

Slick
 
N0rt0nelectr@ said:
I have seen it where the capacitor in the old mags have gone bad. Replacing them with a modern equivalent by a competent rebuilder and a rewind of the armature will make a world of difference.
John in Texas
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To be more specific, absolutely EVERY original capacitor that I have taken out of a K2F mag and tested with a meggar was internally shorted (electrically leaking). The amount did differ but NONE were electrically functional...none! Yet many did create a bit of spark but few would run long enough before dying.
 
When you finally get tired of Lucas magneto problems - bite the bullet, buy a Joe Hunt magneto and enjoy easy starting.
 
jseng1 said:
When you finally get tired of Lucas magneto problems - bite the bullet, buy a Joe Hunt magneto and enjoy easy starting.
Click to expand...

The only problem I ever had with a Lucas K2F was after 40 years the internal capacitor crapped out. It was always a one kick starter.

It was rebuilt by Doug Wood, and I timed it dead nuts on both cylinders, which I subjectively feel has taken some of the vibration out of the engine. It is still a one kick starter, but my leg is not.

The new polystyrene capacitors will likely last 100 years.

Slick
 
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Who's a reputable mag rebuilder these days? Preferably in the States. I've got a k2f and k2fc that should be gone over.
 
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