If float isn't level

with the bowl (mine is at a 10-15 degree angle and well below the lip) is that out of whack enough for a miss, rough running..?
I have had to swap bowls out so, not sure where my float was on the others, I don't have the adjustable's yet, mine is the old "move
the brass seat" adjustment. I've been chasing a rough running condition for awhile now, at all rpm's. Was thinking if that is the case,
it should still run smoothly at idle at least ? Just need someone to verify, obsessed with it and can't leave it alone ! Good fire, compression, valves set, carbs gone through, (several times now) made sure chokes are open.
New points, checked and rechecked gap. I know, the ignition or carburetion dilemna... have done a search and of course there's plenty
on the subject, but nothing addresses my specific question. Sorry to flog it some more. It is a 69 Fastback.....

Thank Ya.

Essentially, you are saying, "I have a miss and a rough running condition" Could it be "A" ?

You are chasing the wrong end of that issue. I wouldn't focus on a certain part "A", until the observed symptoms suggests that part. In other words, you need to figure out the conditions that characterize your "miss", and test those things that your observations indicate as likely culprits.

If you start out with "could it be this?" and then change that part to be sure, then you will eventually change out every part you suspect is to blame, both good and bad parts. Also, you will have gained no intuition about the systems on your bike because you are just throwing parts at the bike, not diagnosing and testing...

So,... How would you characterize your miss?

Is it an idle issue or does it occur while riding? If riding at what throttle position. Put a piece of tape on the throttle and mark closed, 1/4, 1/2, 3/4 and wide open. See if the missing occurs at the same throttle opening in different gears. This would point to carb trouble and help start to eliminate which carb circuit is causing it. Also, with the engine warmed up try putting the choke on to see if it runs worse.
If it occurs at the same rpm in different gears at different throttle positions it is likely ignition related.

Thanks Guys,
Don't need to ride it, just by slow twisting the throttle, it acts as though the choke is on on the R side,
just won't clean out.
Should've mentioned it doesn't have the characteristics of when running out of fuel, that's why
I question float level in the first place.
Chokes have long ago been made to be permanently open. I have double checked both sides.
This all started when I was on my way home after a perfect run, and developed an issue,
made it home, disassembled carbs and discovered a loose main jet on the R side. Aha ! That's it..
nope. Been checking and double checking everything since.

1977years said:

Thanks Guys,
Don't need to ride it, just by slow twisting the throttle, it acts as though the choke is on on the R side,
just won't clean out.
Should've mentioned it doesn't have the characteristics of when running out of fuel, that's why
I question float level in the first place.
Chokes have long ago been made to be permanently open. I have double checked both sides.
This all started when I was on my way home after a perfect run, and developed an issue,
made it home, disassembled carbs and discovered a loose main jet on the R side. Aha ! That's it..
nope. Been checking and double checking everything since.

Click to expand...

BRAND NEW PLUGS.

oOnorton0o
I have owned the bike for 43 years, hence 1977years ... and intimately familiar with it, that's why
I'm so baffled. It has always been a 1 or 2 kick and running, and never any issue like this.
Wiring checked, valves double checked, points as well. Pulled headlight and inspected, all good.
Can't imagine timing, plate screws down tight, and like I said it's an easy starter... even now,
tonight was a first kick. Battery charged, good there. Other than pulling the muffler off to check
for an obstruction (!) don't quite know what's next. Thanks again guys

Torontonian said:

BRAND NEW PLUGS.

Click to expand...

Yes, and the olds tried as well.

So running good, then bad. Disassembled carbs and found main jet loose. Tightened and reassembled and still runs bad. First rule of thumb in trouble shooting go back to what was last fixed. If it was running good before it is highly unlikely that the electrical system or timing is at fault. Especially with points which aren't affected by low voltage like ei. Don't disturb them. The loose main jet caused it to run bad in the first place. Tightening that should have fixed it. My guess, is something wrong in the reassembly. First thing I would do is pull air cleaner off and make sure needles are moving up and down smoothly. If that's okay I'd pull the carb tops off and have a look to see if clip is in proper position on the needle and the needles are straight. Also, drop the float bowls and look at the float bowl gaskets, crud in the bowl. Wouldn't hurt to clean out the pilot jet while you're at it. Look for differences between rh and lh carbs.

1977years said:

Yes, and the olds tried as well.

Click to expand...

Do you have a air filter fitted?

If new points, have you checked insulation is ok?

Thanks guys, all great suggestions. Yes both needles are in the middle slot. Did have a K & N on it but with the frequency of carb removal I have fabric zip tied over intakes, it's a hassle to get filter off and on. Have blown out all the passages every time carbs off and careful with reassembly. I know fuel level is low, of course from looking at it, and it takes way longer than it should to get fuel upon tickiling. Yes, points are new and I inspected that last p.m. I thought I had found the culprit, as the connection for the one set (the metal tang) was bent back against the plate... nope. Guess carbs will come off once again tonight, my thoughts are maybe I have bowl gasket placed wrong, covering the pilot jet, which would be a huge surprise... But little else to explain it at this point. Man, it was runnin' so good, I forgot how much I missed
the Norton growl. Now I'm missing it again ! In spite of it still starting on 1st kick, my 60 year old knee (that has 2 screws
in it from a Harley Davidson kicker failure) is getting tired of starting, restarting.
thank You all.

Points always add a different possibility of problems than electronic ignitions do. Certainly with a problem on a single cylinder you have more to examine with a points ignition. A rich looking plug can either be an overly rich mixture from the carb or a weak spark.

Start the bike, then spit on the right exhaust pipe. The pipe should be so hot that the spit bounces off with a puff of smoke. If the pipe is "just hot" and the spit rolls down the pipe, then that cylinder isn't firing, and the reason the pipe is somewhat hot is because air is heated when it's compressed, so the exhaust pipe being warm does not mean the cylinder is firing at all...

If you pull the plug after running the bike, the plug color should tell you which way to go... In fact, maybe take a picture of it and post it.

Any smoke of any sort out the right exhaust pipe? blackish or whitish smoke?

Any popping out the right exhaust pipe?

Yeah oOnortonOo, I should have mentioned I verified it was R side by the pipe temperature...Thanks
to everyone that responded. Sorry I'm just now gettin' on here, but my 60 y.o. carcass still has to
work, and will for the foreseeable future.... SO, got home did a few things Ya do when
Your carcass gets there,,,took care of the dogs, ( better 'n most people...my opinion..)
Then straight to the shop. Thought about it all day, and knew that R carb had to come off...
I twisted the throttle, again to verify synchronicity and noted a spring noise, a catch,
as I did it. Well, clearly that's not normal. pulled the carb, pulled the slide... um, there's
the needle up with the spring as I pulled it out, NO CLIP....
htown16, You were right on, something screwy since reassembly.. I said I verified needle was in middle slot..well I did , but obviously it wasn't snapped into the slot of the clip and even if it was on re-assembly, the clip obviously didn't get seated correctly under the spring. I got careless, alot of it out of frustration.
I went ahead and blew out all the passages again since it was apart, but running 2 filters on each side,
I would have been surprised something was clogged... reassembled, installed, tickled, fired up 1st
kick and I could tell it was back to it's old self !!! took it for a quick 5 mile spin, all good. will dial in carbs next couple rides.
I hesitated posting about the issue due to owning it as long as I have and the numerous times I've had the
carbs off through the years. But I was getting to my wit's end knowing I've never had a situation like this with it.
Obviously, float level isn't overly crucial on my bike. I guess this will be an addition for folks searching
for an issue like I had. Sure is a load off of my 'ol brain. Such a unique sound, that growl, and so good to have it back !
Thanks again everyone.

You may again continue in your endevour to alleviate the boredom brought on by the demise of the British motorcycle industry. Be safe.

The only reason I suggested that was because I did the same thing.

This is a great place.
Best quote I've seen on here-
"Frankly I think I'm getting too old to continue messing with Commandos. If they weren't so sweet when running perfectly, I'd give up."
David