New Norton Owner; tuning questions

Status
Not open for further replies.
Well, I certainly feel like an idiot. I guess that's OK. I swear I've tried pulling the chokes up on all of the other Premiere's I've fitted and it has been substantially worse. I just find it amazing that I've gotten the bikes to all run good with the chokes down. I can't believe I've gotten every other part of the tune wrong enough to compensate for the chokes down... seems unbelievable. BUT, you all have more experience than me, so I won't let my stubbornness overcome my need to learn.

Once I get the new exhaust seals in, I will double check fuel level, re-install carbs, keep the chokes in the upward position, and return to normal jetting and see how it goes. Hopefully I can accomplish that in the next few days.

Fingers crossed I don't make any other dumb mistakes.
 
Lots of people make that mistake with the choke
I nearly bought a t160 that the seller had had trouble with for 12 years
Guess what he had the choke on
He'd fitted trispark ignition he had the bike rewired new carbs top end rebuild etc etc
I pointed out the choke was on full and he withdrew it from sale
Should have kept my mouth shut
The Saudi police had a bit of a problem with the choke as well so don't beat yourself up
Just go to it and sort it out best of luck with it
 
A lot of people don't know how the amal style carb design works. It's often reflected in their questions and comments on the forum. I had 240 mains in my bike for decades and couldn't go faster than 83 mph... until I learned that my problem pointed to the main jet size. I put the stock size in (220) and zoomed right past 83mph... We all pay our dues, but it pays off eventually.
 
Most of us that talk about the choke, have probably experienced it.
At least this guy has.
Seems counter intuitive to pull the cables tight to open the choke, until you understand how they work.
 
adunham1 said:
Well, I certainly feel like an idiot. I guess that's OK. I swear I've tried pulling the chokes up on all of the other Premiere's I've fitted and it has been substantially worse. I just find it amazing that I've gotten the bikes to all run good with the chokes down. I can't believe I've gotten every other part of the tune wrong enough to compensate for the chokes down... seems unbelievable. BUT, you all have more experience than me, so I won't let my stubbornness overcome my need to learn.

Once I get the new exhaust seals in, I will double check fuel level, re-install carbs, keep the chokes in the upward position, and return to normal jetting and see how it goes. Hopefully I can accomplish that in the next few days.

Fingers crossed I don't make any other dumb mistakes.
Click to expand...

We’re all idiots. Tell us if you get it going a bit better.
 
  • Like
Reactions: baz
adunham1 said:
Well, I certainly feel like an idiot. I guess that's OK. I swear I've tried pulling the chokes up on all of the other Premiere's I've fitted and it has been substantially worse. I just find it amazing that I've gotten the bikes to all run good with the chokes down. I can't believe I've gotten every other part of the tune wrong enough to compensate for the chokes down... seems unbelievable. BUT, you all have more experience than me, so I won't let my stubbornness overcome my need to learn.

Once I get the new exhaust seals in, I will double check fuel level, re-install carbs, keep the chokes in the upward position, and return to normal jetting and see how it goes. Hopefully I can accomplish that in the next few days.

Fingers crossed I don't make any other dumb mistakes.
Click to expand...

NOT an idiot, you included enough information for us to help you.
Watching intently, listening, and, if you come across a very knowledgeable person at a show/meet/ride.... chat him up. Buy beer/food/coffee as needed. You can learn a lot, PROVIDED he is willing to share.

Rather than just memorizing which way the choke is on/off, learn HOW it works (by providing air restriction in this case) and you can look at ANY carb, and know.

...and, you didn’t use a HAMMER!
New Norton Owner; tuning questions
 
  • Like
Reactions: baz
Every new British rider I've had - step 1: Remove Choke(s). IMHO, need to tickle = no need for choke! Of course, if you have more "normal" carbs that don't have ticklers then a choke can be useful.

On of the things that cracks me up is people saying that their bike won't start/run or idle when cold without "a little choke". Putting the choke down part way does nothing for starting/idling and only serves to confuse things if you open the throttle far enough to expose the choke to the air flow.
 
They wouldn't have been installed at the factory if they weren't needed. My bike likes the choke during warmup. Always has. 45 years with it now.
 
maylar said:
They wouldn't have been installed at the factory if they weren't needed. My bike likes the choke during warmup. Always has. 45 years with it now.
Click to expand...
What sort of temperature are we talking?
 
marshg246 said:
On of the things that cracks me up is people saying that their bike won't start/run or idle when cold without "a little choke". Putting the choke down part way does nothing for starting/idling and only serves to confuse things if you open the throttle far enough to expose the choke to the air flow.
Click to expand...

EXACTLY !!
 
Not an idiot. An idiot would have put on a Mikuni! (Somebody will surely take that bait)

Just think about how much experience you now have working on Amal carbs. Most everything I know is because I had to do it two or three times to get it right!
 
Thanks for the encouragement, everyone. I'm really looking forward to getting back to work on it.

I had planned to work on it a bit today, but I'm having kidney issues and had to go to the hospital for an x-ray and blood work. Nothing too serious, but the pain kept me from doing much of anything.

Hopefully I can get back to it in the next few days. All this chat about the choke makes perfect sense; and makes senses why my plugs were so dark and sooty. I'm pretty excited to give it all another shot.
 
baz said:
What sort of temperature are we talking?
Click to expand...

Never really thought about it. It's a judgement call, second nature to me after all these years. But since you asked...

Below 70, with a cold engine. Tickle, full choke. Start the motor and immediately raise the choke by maybe 1/4". It'll idle while I suit up and close the garage door. Raise the choke and ride off. Colder, like 50-ish, it takes longer before I can turn the choke off without the motor stumbling.
 
maylar said:
Never really thought about it. It's a judgement call, second nature to me after all these years. But since you asked...

Below 70, with a cold engine. Tickle, full choke. Start the motor and immediately raise the choke by maybe 1/4". It'll idle while I suit up and close the garage door. Raise the choke and ride off. Colder, like 50-ish, it takes longer before I can turn the choke off without the motor stumbling.
Click to expand...

As has already been mentioned, if you raised the choke slide 1/4” with the bike on tick-over, it is actually buried up inside the throttle slide and doing absolutely no ‘choking’.

Any effect it is having in those circumstances is either coincidence or placebo.
 
If you raised the choke slides an 1/8" it would have no affect on idle
The lowest temperature I ride in is about 5° c unless I'm caught out somewhere
I never let my bike idle whilst I don my gear
I tickle the bike start it maybe tickle it again whilst it's running then keep it running with the throttle and ride off as soon as I can
I don't thrash the bike until it's warmed up a bit
 
Fast Eddie said:
As has already been mentioned, if you raised the choke slide 1/4” with the bike on tick-over, it is actually buried up inside the throttle slide and doing absolutely no ‘choking’.

Any effect it is having in those circumstances is either coincidence or placebo.
Click to expand...

I haven't actually measured how high the choke is, that's just a guess. But I assure you there's some "choking" going on, and it's less than "full" choke.

Edit: Next time I have the air filter off I'll get a measurement or a pic of that.
 
maylar said:
I haven't actually measured how high the choke is, that's just a guess. But I assure you there's some "choking" going on, and it's less than "full" choke.

Edit: Next time I have the air filter off I'll get a measurement or a pic of that.
Click to expand...

Choke fully on (No.3 slide):
New Norton Owner; tuning questions
 
The PARTIAL CHOKE (1/2 choke) position will do nothing at idle, but, as you get underway, and use more throttle, the slide reaches (and then goes higher than) the choke level, and then the mixture richening effect is very real.
So, unlike a butterfly choke, it can be used to richen the midrange (needle) and top (main) only as well.
I have used it to “acid test” suspected weak(lean) mixture.

Also, if your ever out on the road, and it turns off, say, 0F.... it will help. :D

As illustrated in LAB’s post, the TINYEST amount of pull back from full choke will give some variability.
 
Status
Not open for further replies.

Similar threads

D
Can you give me advice about tuning/jets etc on my single Mikuni VM34
2 3
Replies
47
Views
1,591
DennisMo
D
K
A couple of problems for unsuspecting norton owners.
2
Replies
24
Views
1,969
Saber
Saber
Big_Jim59
Tuning Issues
2
Replies
23
Views
1,078
Big_Jim59
Big_Jim59
acotrel
Norton tuning
Replies
0
Views
509
acotrel
acotrel
TomU
  • Locked
Tuning Dual Mikuni VM32s on a 750 Combat
2 3
Replies
40
Views
3,102
SteveA
SteveA
Back
Top