Excessive smoke/popping when taking off on my 1971 Norton

Help! I am new to the wonderfull Norton world and I have some issues i would like to resolve. First, when my bike starts it fires up with excessive smoke and then little by little gets better. However, when I have ridden it for about 15-20 minutes and I am at a stop and blows an Enormous cloud of white smoke and sometimes dies out??? What is this problem. I am also having problems with excessive popping! If and when I get going (after the huge Cloud of Smoke) it starts popping as I try to accelerate. This happens during and before constant acceleration. I have absolutely no idea and would love some advice or tips. I have a 1971 Norton Commando with amal Carbs. Please help! Anything will do.

-Angel

Re: Excessive smoke/popping when taking off on my 1971 Norto

Ugh, sounds like both of my '72's, I had to start at crankshaft and work my whole way up to the wiring to ignition with years of online handholding to get thought it. Gals and bikes of this age all have a history to deal with before smooth sailing.
Could just try new hone and rings as simplest piecemeal start. Put in hotter plugs and may get a hint of how it should run, till they foul up.

Re: Excessive smoke/popping when taking off on my 1971 Norto

Thanks for the reply, I will definately take that into consideration. Also, I kind of decided to mess with the carb screws and i think that when all of the problems started. Could that have anything to do with it?Thanks

-Angel

Re: Excessive smoke/popping when taking off on my 1971 Norto

I'm sure a lot of members will add their ideas but my first thought would be your oil level. How full is it on the dipstick and when do you check it? Cold or after it has run enough to be hot and the initial smoking has cleared up? You could have mechanical problems or adjustment issues for sure, but no sense worrying about that until you're sure the oil isn't way overfull. Easy to do on a Commando if it wet sumps and you aren't aware of how to deal with that.

Re: Excessive smoke/popping when taking off on my 1971 Norto

Don't think the carbs caused this unless they allowed so long a running life it used up the internals or they were so bad it didn't run for decades so rust and cob webs eat the sealing surfaces. Could also just be a bad head gasket seal if a new behavior. I've run too much with chokes on, balance tube leaking, manifold gaskets hanging out as well as float bowel hanging gap jawed and didn't smoke or even run that bad till lower rpm and starts, which clued me to look and poke around. I've seen over filled tanks so wet sumped it fooded out 2 quarts of added oil it didn't need all over the floor for a lazy man's oil change, but engine started and idled fine w/o any smoke but what spilled on outside of headers.

Eventually all Cdo owners either become fully experienced and equipped diagnostic specialist mechanics or someone else ends up with it after awhile.

Re: Excessive smoke/popping when taking off on my 1971 Norto

It could totally be your carbs!
I worked on a bike set so rich one time that it blew so much white smoke It was absolutely incredible.

Since the issues started AFTER you started messing with the carbs and turning screws,
Start by setting them back to spec.

Re: Excessive smoke/popping when taking off on my 1971 Norto

Yes, that's what I am thinking. I have always had issues about tuning my carbs. What are the Original Specs?? do I ave to adjust all for screws. I have not touched any of the bottom ones. Only the ones that are in a 45 degree angle?How would i set them to "Stock" on the 45 degree screw?Thanks

Re: Excessive smoke/popping when taking off on my 1971 Norto

SYNCHRONIZING TWIN CARBS FOR IDLE AND SLOW SPEED RUNNING:

This is one area where there is a lot of misinformation on the process, even in workshop manuals. This will outline the simple methodical professional shop steps to synchronize your twin (or triple) carbs, once all the prep and rebuild work above is completed.

1. Adjust pilot screw to 1 ½ turns out (turn all the way IN till stops then count 1 ½ turns OUT). This assumes that the pilot gas jet has been cleaned as above)
2. Open the throttle to full open and check that each throttle slide is up the maximum amount (i.e. disappears up into the carb body). Adjust the cable adjusters until an equal amount of throttle slide is seen, just peaking through on each carb. It is surprising the number of bikes I have seen with a major difference in the full open position.
3. Once cables are adjusted for full open, fully turn out the throttle adjusting screws (to past were it touches the throttle slide)
4. Insert two 3/16" dia drill bits (or 4" long peice of round bar) into each carb (diameter size should be adjusted to suit the throttle cut away), seating the drill bit under the throttle slide, so that they stick out the end of the carb evenly. Screw in each throttle stop screw until the drill bit "dips" a little, find the happy spot, where the screw just touches the slide. Repeat for the other carb. With a felt pen mark the screw head flat-slot position for reference on each carb body..

5. With the drill bits still in place, perform the fine cable adjustment - by gently opening the throttle and seeing that each drill bit moves at precisely the same moment. Adjust the cable adjusters on the carb or on each cable so that movement is even (should be only ¼ - ½ turn each).
6. Start the bike, it will likely idle too high, wait for engine to warm up, then adjust each throttle stop screw down (out) by EXACTLY the same amount, i.e a ¼ turn at a time on each, using the felt pen reference mark to make sure the adjustments are same. The idle should be even and by blipping the throttle the pick-up should also be even.
7. The pilot jet air screw may be adjusted at this time, but by very little, no more than ½ to 3/4 turn in either direction. The effective range of adjustment for the pilot jet is 1 turn to 2 1/2 turns. This is where a bit of skill & experience comes into play. By turning one screw a little at a time with the engine running (on both cylinders) you can gauge any difference in running and find the sweet spot. When you hear the engine revs race, you want to turn it back a 1/8 to ¼ turn - the sweet spot is not at the extreme. The idle may need to be dropped equally again.
If you have to screw it in all the way or out all the way, then the pilot circuit is still clogged, maybe not completely, but enough to affect the running. Go back and clean the jet.


Better Yet....... Check out this Link:
http://www.jba.bc.ca/Bushmans%20Carb%20Tuning.html

Re: Excessive smoke/popping when taking off on my 1971 Norto

White smokin' be oil issues , black smoke be rich fuel. Yes check the oil level on the tank dipstick ,it should be just above the L mark after letting it run and settle for a minute. New plugs help too. What color be they when pulled and inspected ?

Re: Excessive smoke/popping when taking off on my 1971 Norto

its kind of a sooty black color.

Re: Excessive smoke/popping when taking off on my 1971 Norto

Angel,
You really need to get a copy of the shop manual and parts list. I don't know how one can get very far without them. Parts numbers for ordering and the names of things. They are available free on line.

http://britmoto.com/

Check the oil level after the bike has run for a few minutes. A lot of the oil could have drained into the crankcase making it appear that you are low on oil if you check the tank after the bike's been sitting for a while without running the bike to clear the crankcase.

Seeing you are in the UK, think about hooking up with the Norton Owners Club. People like helping you get through the steep part of the learning curve so much that you might have a hard time getting rid if them, but nothing is better than boots on the ground live people to look, listen, and even smell what's going on. Speaking of smelling, take a whiff of the end of you mufflers the next time you're out riding. If the problem is in the carbs, that amount of smoke is going to smell of gas.



http://www.nortonownersclub.org/