Frustrated Beyond Measure

I know you don't want to go down the progressive pile of new parts fitting rabbit hole .
Clean up or eliminate entirely the old kill switch .
Clean up or replace the ign. switch .
Tighten up the connections on a new battery . Clean fuse contact points .
It's either electrical or fuel delivery related . Determine which .
Good luck and enjoy .
 
Big_Jim59 said:
Absolutely not. It means that the pilot jet circuit can be opened, cleaned and inspected. You can see the pilot jet.
Click to expand...
OK, when you look through there you are seeing about 1/3 of the pilot circuit. Between the air screw and pilot jet, there is a passage that goes to the back of the carb and then down to the bottom of the bowl. Those passages are just as important. Also, the two small holes into the throat of the carbs.

Also, a brass sleeve does not fix a worn slide. With the spring removed see how much play there is side to side and front to back in the slide - there should be a little only.

A stock Norton near sea level with the original sized jets will run very well on E10, E5, or non-ethanol gas. They will also idle perfectly with Premier carbs and Tri-Spark ignition (probably with other EIs with idle stabilization as well). They will also start hot or cold with no throttle and no choke.

Since you say the midrange is good, if it's a carb issue (probably is), it's the slide or pilot circuit.

I agree with those mentioning eliminating timing - ignition is easy to check, valve is even easier. Timing cover off, align pinion and intermediate gear marks and count the rollers between the two sprocket marks - if 10 you're OK. Adjust the chain while there.
 
Update. This morning I set the timing maybe one degree retarded to see how that went. It didn't. It was hard to start from cold with full tickle. This evening I went one degree advanced and it banged right off from cold with full tickle. Then I banged off when hot. It still ran like crap on the left side with eradicate idle.

Had high idle and then dropped to hardly running. I do think the issue is these carbs or at least the left one. When Debby left me the notes on this bike she made sure to use the term "used Amal 932s." Why would she emphasis the word "used?" My guess is they were a local club members take offs.
 
Depends who built the motor its easy to get the 10 pins on the timing sprocket wrong, as for running a toggle switch for ignition is all good been running one on my 850 Featherbed for over 40 years running both Boyar and Joe Hunt.
I say the carbs are not right on Debby's old bike more than anything and as Greg said be easy to eliminate timing and other things.
My original Amals had that much wear in the slides (from only running them for 4 years from new), the bike didn't like to idle but once going it ran ok without any problems for a few years until I replace with new Amals back in 1980, but 13 years ago I replace those Amal with Jims PWKs set up for my Norton but 6 months ago I pulled the old Amals out, pulled them down and unblocked the left carb pilot jet and the bike is running the best it has ever been running with the JH maggie and with all the years of running these replacement Amals the slides are still good no wear at all and the replacement Amal are a lighter grey than the original Amals and don't seem to be made of pot metal even although I brought them in 1980, so maybe Amal knew about the pot metal Amals way back then.
The new Amal in 1980 cost me $100 for both ordered through the Norton owners club in my home town at the time, took about 3 months to get them and had to send one back as they sent 2 left hand Amals, this was the days before the internet lol.

Ashley
 
Big_Jim59 said:
Update. This morning I set the timing maybe one degree retarded to see how that went. It didn't. It was hard to start from cold with full tickle. This evening I went one degree advanced and it banged right off from cold with full tickle. Then I banged off when hot. It still ran like crap on the left side with eradicate idle.

Had high idle and then dropped to hardly running. I do think the issue is these carbs or at least the left one. When Debby left me the notes on this bike she made sure to use the term "used Amal 932s." Why would she emphasis the word "used?" My guess is they were a local club members take offs.
Click to expand...
Yes it's kind of pointing to carbs but a good plan to check ignition etc too. My own experience is that Nortons are not very sensitive to ignition timing. A degree or two is unlikely to make much of a difference.

My concern is those carbs certainly have a history. I have friends who have sleeved and upgraded old Amal Mk1s to premier state successfully. But they have had heaps of experience and full engineering shop equipment. With these carbs you don't even know what you don't know. Sadly the previous owner cannot help.

As suggested above can you borrow carbs from someone to test?

Or send yours to an engineer with lots of reliable experience. My guy is in New Zealand so not much help to you. Even he gets bluffed sometimes. He always fits the carbs to one of his own bikes to test before he returns them to tge owner.

There may come a time you will need to buy new Premiers. Unfortunately they are stunningly expensive nowadays.
 
As Greg has said the pilot jet chambers have a sharp 90 degree turn and easy for those small passages to be blocked as well, when I pulled the old Amals down to reinstall on my Norton 6 months ago the left Amal pilot jet chamber was so blocked took 2 attempts to unblock, soaking in vinegar for 2 days at a time and the fine wire poke then high compress air before what was blocking it shot out and hit my finger that I had over the pilot holes with force, it was like a needle hitting my finger, so no matter how much you clean the passages there could still be something there from that 90 degree turn.
Soaking in vinegar is an old trick for cleaning Amal carbs and will bring them up like new without hurting them and took me 4 days of soaking (I have a lot of patients lol) them before I got that passage clear and 2 attempts of putting them on the bike before it came good.

Ashley
 
Big_Jim59 said:
Oh how times have changed however, I was making $5.50 an hour back in the 80s and $100 was pretty dear.
Click to expand...
It sure was in the days, I was earning about $70 a week if that and after paying board, cigs and beer wasn't much left in the kitty, but could buy a 750ml bottle of Bundy rum for $6.55 and a 40oz bottle for just under $8.00, a 40oz (1124ml) bottle now is over $65.
 
When turning the air screws has no effect on the running, then that needs fixing.

Every Brit I've ever worked on has been sensitive to the smallest adjustments, typically within a range of 1/8 of a turn, and typically less than 1 1/2 turns out total.
They're rarely identical both sides, either.
If it were my bike i would find someone with a known good pair of carbs to substitute before swapping anything else.
Your symptoms would indicate lean running, IMHO
 
ashman said:
As Greg has said the pilot jet chambers have a sharp 90 degree turn and easy for those small passages to be blocked as well, when I pulled the old Amals down to reinstall on my Norton 6 months ago the left Amal pilot jet chamber was so blocked took 2 attempts to unblock, soaking in vinegar for 2 days at a time and the fine wire poke then high compress air before what was blocking it shot out and hit my finger that I had over the pilot holes with force, it was like a needle hitting my finger, so no matter how much you clean the passages there could still be something there from that 90 degree turn.
Soaking in vinegar is an old trick for cleaning Amal carbs and will bring them up like new without hurting them and took me 4 days of soaking (I have a lot of patients lol) them before I got that passage clear and 2 attempts of putting them on the bike before it came good.

Ashley
Click to expand...
It's clear to me that there is still something blocking the left hand carb pilot jet. I gotta jug of vinegar in the shop for just such an occasion. I guess the old carbs are coming back off. I'll keep you posted.

I am no stranger to this. I had the exact same trouble trying to clear the pilot jet on a Monobloc at that carb has a removable jet!
 
Torontonian has a very good point about the kill switch, which is often overlooked. In the original setup the ignition feed goes through a long wire up to the handlebar controls, through a set of points and back through another long wire to feed the ignition. When you push the kill switch the points open and interrupt the feed , but with age the points and the wire connectors often become corroded and a lower voltage to the ignition is the result. I always modify my bikes by connecting the power from the ignition switch to the ignition via an a/b relay and use the kill switch points as a trigger for this relay.
 
dave M said:
Torontonian has a very good point about the kill switch, which is often overlooked. In the original setup the ignition feed goes through a long wire up to the handlebar controls, through a set of points and back through another long wire to feed the ignition. When you push the kill switch the points open and interrupt the feed , but with age the points and the wire connectors often become corroded and a lower voltage to the ignition is the result. I always modify my bikes by connecting the power from the ignition switch to the ignition via an a/b relay and use the kill switch points as a trigger for this relay.
Click to expand...
I would be more concerned with the kill switch if it had the original Lucas rocker switch. These Lucas items were almost on the tune up list since the contacts failed so often. I had one on my 750 and it was a real pain because I just never used it. I have a modern aftermarket switch on my bike which helps a great deal and it has already had a clean.
 
Old carbs, sleeved means someone was trying to solve an old issue. Have the needles and needle jets been renewed recently? With out of round needles can give low rpm issues. Why did you change the needle clip position from what Debby had? My 850 with 40 thou overbore runs better with clip in lowest notch, needle raised to richest position. At middle it would always be too lean and pops common.
 
Needles and jet wear from vibrations and more so with hard mount manifolds, my Norton was an everyday rider from new to 2013 except for rebuilds or work, I install an Amals rebuild kit every 3 years when it was an everyday rider without fail, as the motor vibrates through the manifolds the needles would vibrate and wear the jets oval and give bad running, but I run 270 mains in my Amals, Amals rebuild kits are a cheap investments for good running every so often, people seem to over look things like jets and needles.
 
Big_Jim59 said:
Update. This morning I set the timing maybe one degree retarded to see how that went. It didn't. It was hard to start from cold with full tickle. This evening I went one degree advanced and it banged right off from cold with full tickle. Then I banged off when hot. It still ran like crap on the left side with eradicate idle.

Had high idle and then dropped to hardly running. I do think the issue is these carbs or at least the left one. When Debby left me the notes on this bike she made sure to use the term "used Amal 932s." Why would she emphasis the word "used?" My guess is they were a local club members take offs.
Click to expand...
IMHO, coincidences are causing you to work against yourself. One degree of timing either side will not change starting and unless racing, you're never discern the difference. I shoot for 30 degrees with E10 and Tri-Spark and accept 29-31 - too difficult to get exact by yourself and no noticeable difference. Of course, I've verified that my marks are exact.

If you don't want to replace the carbs, at least make sure the entire pilot circuits are open, that the fuel level is the same in both bowls, that they are perfectly mechanically synced at the top and bottom of the slide movement and that you start out with the air screws 1-1/2 turns out. Then once warmed up, set the idle to 1100 and blip the throttle from off to less than 1/4. If it stumbles, turn the air screws in sightly and keep doing that until it doesn't stumble, or you've turned them 1/4 turn in (now out 1-1/4). If that does not fix the stumble, you will not get the carbs to work right (still assuming midrange is good).

Here's how I've done it for MANY years: https://www.gregmarsh.com/MC/CarbSync.aspx
 
ashman said:
Needles and jet wear from vibrations and more so with hard mount manifolds, my Norton was an everyday rider from new to 2013 except for rebuilds or work, I install an Amals rebuild kit every 3 years when it was an everyday rider without fail, as the motor vibrates through the manifolds the needles would vibrate and wear the jets oval and give bad running, but I run 270 mains in my Amals, Amals rebuild kits are a cheap investments for good running every so often, people seem to over look things like jets and needles.
Click to expand...
I agree. I once put my hand on a carb bowl while the bike was reved out on a dyno. The high frequency vibration was just like an electric shock. If you held on your hand would go numb. The vibration seemed to penetrative right into your hand. Was a real eye opener to me.
 

Similar threads

S
Measuring Cam Wear
2
Replies
38
Views
1,734
Stephen Hill
S
K
  • Locked
Dial indicator to measure timing ?
Replies
19
Views
2,113
MexicoMike
MexicoMike
Big_Jim59
Tuning Issues
2
Replies
23
Views
1,157
Big_Jim59
Big_Jim59
Britstuff
MK II 850 Commando 1974 Amal Carb choice.
Replies
13
Views
627
acotrel
acotrel
K
A couple of problems for unsuspecting norton owners.
2
Replies
24
Views
1,983
Saber
Saber
Back
Top