MY Commando won't stay running...

swooshdave said:

SierrasCafe530 said:

I was told they will work, I just need to run it richer... Oh and since I'm a girl, I guess that would make me a Loud bitch, not a dick. lol... They are not all that loud anyways.

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I'll be right back, I'm making popcorn. This is going to get good. :mrgreen:

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No no no... I'm a lover not a fighter. That was all in good fun. Just really looking for some answers to try to get my bike running smooth.

Hi sierra.
Yeah, I don't know about those straight pipes either. Just don't seem right to me.
They may be fine and it's just those crappy Anals.
I fought with those damn carbs for years, had them sleeved, popped out the idle jet for the screw in the bottom one, changed jets, needle positions, everything.
Without looking at your set it is hard to know what is going on all I do know is since I got me a set of JS PWK's it has been smooth sailing.
It starts right up and idles after about 30 seconds of warm up.
Now not saying yours can't be fixed, just saying I'd have to see them.
I have a 73 850 which I am going to "restore" and it's a cafe' like yours. I'm tossing between a Dunstall look and a stock Roadster look but that's another thread.
Where are you at

Guido said:

Hi sierra.
Yeah, I don't know about those straight pipes either. Just don't seem right to me.
They may be fine and it's just those crappy Anals.
I fought with those damn carbs for years, had them sleeved, popped out the idle jet for the screw in the bottom one, changed jets, needle positions, everything.
Without looking at your set it is hard to know what is going on all I do know is since I got me a set of JS PWK's it has been smooth sailing.
It starts right up and idles after about 30 seconds of warm up.
Now not saying yours can't be fixed, just saying I'd have to see them.
I have a 73 850 which I am going to "restore" and it's a cafe' like yours. I'm tossing between a Dunstall look and a stock Roadster look but that's another thread.
Where are you at

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The strait pipe look takes some getting use to. I like Brat style and Cafe style so I made my own style, Bratfe... Haha. I plan to put a flat track seat on eventually. I just haven't found one that will work with her tank width and frame length.

I've been looking into a Mikuni single carb but already dropped close to two grand getting her going. She had been sitting almost 30 years. I've tried my best to do as much of it myself. I rebuilt the carb (needles, gaskets, slide, screws), did the clutch pack, all new lines, pulled out the oil tank and did an over haul/cleaning on it, Boyer ignition and a lot more. I did everything that I thought was necessary to get her going. I just feel a little out of my comfort zone with the carbs, I can handle a single carb set up on a car, but cant seem to get the hang of this two carb thing. Do you know anyone around here that work on Norton's. I have a few friends in San Jose, but don't really wan to trailer her down there.

I'm located between Oroville and Chico.

I am not at all qualified to join in this thread, but I guess that is no reason to hold back....

On this forum it has been said many times that a problem that seems to be carb related might turn out to be electric related. Could the change to Boyer ignition have exposed an issue with your charging circuit? Have you tested the output of the battery before starting; and do you keep the battery on a trickle charger between rides? Does the battery need replacement? A low charge may be a real contributor to the problem; although previous posts suggest that perhaps not the primary issue.

And is it worth changing the spark plugs to see if that makes a difference?

Chris T said:

I am not at all qualified to join in this thread, but I guess that is no reason to hold back....

On this forum it has been said many times that a problem that seems to be carb related might turn out to be electric related. Could the change to Boyer ignition have exposed an issue with your charging circuit? Have you tested the output of the battery before starting; and do you keep the battery on a trickle charger between rides? Does the battery need replacement? A low charge may be a real contributor to the problem; although previous posts suggest that perhaps not the primary issue.

And is it worth changing the spark plugs to see if that makes a difference?

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I don't think that it is the battery. I keep it on a trickle charger and the light was green this morning when I tried to ride her. But you never know, it only about 3 months old, but with my luck... I'm not against trying the small stuff. The spark plugs looked good, but it would be an easy swap to see if there is any difference. I do believe it has something to do with the carbs though. I don't feel I ever really got them right from the get go. That's why I was hoping to find someone around me that knows Nortons. I don't really trust her with a lot of people.

Oh dear me yes them long dong open drag like pipes can work a treat with Amals on a Snorting Norton. The extra length puts a slug of air mass in place of a restrictive baffle tube and can help out on the lower end tune by velocity of gases. I had the most wonder board power band - idle to 9000 rpm on my P!! dragster with 1 3/8" pipes half a long as yours. It had a loopy 600 rpm idle from wild cam. Not sure what is needed to make it work so good just know it can in spades! Looking at online header calculators implies 40" long pipe for the standard cam and valves to enjoy 4500 torque peak. Shorten up to rise the peak rpm. Someone's got to do it and rub it in our faces please : )

O yeah open pipes are known to breath better so tend too leaness so try richening up.

A blocked carb(s) pilot jet can have the same effect :!:

You've come a long way in getting that machine to function. You want simplicity and ease of starting/running? Time for the Mikuni, call me at Rocky Point Cycle I have Mikuni kits. The Amals are good just very prone to gum up their pilot circuits; Mikunis do the same thing if neglected, but the pilot jet is easy to get at and very easy to clean/replace.

RS

I know all the purists out there are going to totally bash me for this, but that's ok, cause, they have their opinions and I have mine, and we all belong to the same Norton family, so its all good. Why don't you go with a single Mikuni, or Amal? What kind of riding do you do? If you just want to go out and have some fun on your Norton, not go racing with it or take it to Bonneville, then the Mikuni is the way to go. Everything that has been posted in response to your questions is all good, sound advice. Start with all the simple stuff, like air leaks and bad wiring/connections, and then move on to the big stuff. It has been said before, many times, that 90% of carb troubles are ignition related and vice versa. You may have a compound problem, more than one thing going on at the same time (very common with a Norton), so you need to start eliminating things, one by one. The Mikuni is simple to install, simple to tune. No ticklers, a choke you use only for a minute, and not at all once warmed up. If it is properly set up, your Norton will be a one kicker and idle all day at 700-900 rpms. And you won't notice ANY difference in performance unless you go racing with it. What's not to like???? Mine has been on since 1982. I have rebuilt it once, because it sat for a while, and I moved from the mountains to Florida, so a re-jet was in order.

In your first post you state that the timing keeps getting retarded, you MUST address this issue before anything else, the bike will not run properly or at all if the ignition is not timed correctly and locked to prevent slipping. Your bike seems to have run adequately at least for some time with the existing carbs on it, they will therefore run adequately again with the same carbs when you address the main problem which seems to be timing. If you can't sort this out I can highly recommend taking the bike to Rabers in San Jose, not too far from you and first class people.

SierrasCafe530 said:

swooshdave said:

SierrasCafe530 said:

I was told they will work, I just need to run it richer... Oh and since I'm a girl, I guess that would make me a Loud bitch, not a dick. lol... They are not all that loud anyways.

Click to expand...

I'll be right back, I'm making popcorn. This is going to get good. :mrgreen:

Click to expand...

No no no... I'm a lover not a fighter. That was all in good fun. Just really looking for some answers to try to get my bike running smooth.

Click to expand...

Are you kidding, these old farts need slapped around every once in a while. :mrgreen:

So you have a nice Dunstall seat and tank and you want to ditch the proper cafe look and go flat tracker? Well, ok.

Single Mukuni is for pedestrian bikes, stay with twin carbs.

Amal carbs run fine when: A) NOT worn out, B) NOT clogged with debris from sitting, C) NOT dicked with and messed up, D) properly jetted, which, in most cases people try guessing at it with folklore, rather than science and testing. A Mikuni or Keihin will do ALL of the same.

I took out my 73 Norton Commando 850 yesterday and she ran strong. A little poping when declerating and sputtering a little when I got on the throttle real hard. Today I went to start her and she fired up after a few kicks but cut out as soon as I took off the choke and put her in gear. This happened a few weeks ago too and it was the timing. I put a boyer electronic

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None of us are dating you so who cares about the groin plumbing but do note sufficient testosterone to take on a Norton odd ball! I think your clues is obvious now with the initial review. It ran pretty good once or the pipes would not have remained on. It ran for you pretty good till intermittent symptoms, so scratch off carb as main issue and focus on the Boyer trigger wires or kill switch etc. Even the worse open header will start and idle and give effective performance but touchy to give throttle off idle and not very exciting pull to speed is all but not misfiring and cut out or hard starts. The extra length is definitely in the right direction to make up for lack of baffle sound back waves. You MUST replace the Boyer trigger wires, even if they ain' the issue now they sure will be soon enough. Seek out Greg Fauth kit or make you own after reviewing the variations. Best is bolt on terminals with only the thin bolt or screw head on back side on magnets can clip em and do exactly like you describe.

swooshdave said:

Single Mukuni is for pedestrian bikes, stay with twin carbs.

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Oh yah?

I'm thinking Dave M had it right. If your timing is slipping you need to address that right off. I can't comment on the Boyer. But yes, it ran fine at one time with those Amals on it. If you want to run those straight pipes though, it's going to take some work on getting the Amals tuned for them. Amal has a tuning guide on proper jetting. http://www.amalcarb.co.uk/downloads.aspx

Dave
69S

Hey Sierras,
How are you getting along, everything clear as mud, hehe. ?
Don't stress, you'll get there.
There should be a filter in the bottom of each Carb where the T piece bolts up to the Bowl,
check them out for debris. Slightly blocked, means slightly less fuel, (lean).
Do you understand how the chokes (Air slides) work, ?
Not trying to be condescending, just helpfull.
They act like the Throttle slides,... when right down, (closed), they are restricting air intake, but they (the air slides)
are there only to assist the very small Idle jets and fine amount of fuel going through the carb at low throttle openings
with a cold motor.
Try to run the bike with the Chokes, partially closed,... that will richen things up, then see if you
can find a sweet spot with the chokes partly closed, where it will run OK.
If not, then it may not be a mixture problem.
When we tickle our Amals, we are ADDING a dose of fuel to the mixture which sometimes is not necessary on a warm motor.
Cold motors sometimes need the help of a little less air or a little less fuel, or both.
I'm sure the Amals can be tuned to run OK with the straight pipes, hell there's plenty of
unrestricted Race bikes out there,but as they told you...
The mixture will need to be fine tuned througout the range, depending on the alteration
to back pressure, (exhaust pulses returning to the head).
If it did run sweet and strong, and the Carbs are too lean, then you may have killed a pair of plugs.
I'd.... check the timing again, look for suspect wiring and earthing, add new plugs, try it,... Read the plugs.
You can read the plugs. If it is lean, you can now do something about it.

My bike is reasonably 'warm', with a pair of Jims Flatslides, it goes very well,... I ride with another Forum member
who has a single Mikuni, std 750 and it goes along very very nicely. Starts, idles, pulls hard, goes well and is trouble free.
There is probably a second hand setup here for sale somewhere.
Keep at it.
AC.
P.S... Tell us about the "cafe 530"..... KTM ?

Hey all,

Thanks for the responses... I should clarify a few things... She never ran great. I only have had her running about two-three months. I got her off a guy that said it just stopped running one day (in 1982) and he never fixed it.

I found out today that my husband recently had a friend (Honda guy) look at my bike and he "adjusted" the carb slides. :evil: ugh!!! This was right before the pipes.

Ever since shes been running i haven't got the carbs right. They either idle to low, sputter to much, ect. I have only static timed it too. I want to put a Mikuni on her but don't have the funds right now. I think i will try to put the slides back up and see if running richer helps. As for the EI, i think its fine, yes i would like to get rid of the coils, but once again i don't have the funds at the moment.

As for Rabers, I know Bob and trust those guys as well as Ken Armann in San Jose, I just don't want to have to trailer her the 200 miles to get there. I was hoping to find someone a little closer.

And as for the pipes, I'm trying to machine some tips on the lathe and some kind of baffle for it. They are only 1-1/2" so it been hard to find something, I will have to make it.

If anyone has any other ideas, please keep them coming. I'm open minded!

-Sierra

AussieCombat said:

P.S... Tell us about the "cafe 530"..... KTM ?

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It stands for me wanting her to be a bad ass cafe racer... Some day. The 530 is just may phone area code. No secret decoder ring needed for it... HAHA

Then go back to the basics and set the carbs statically. This insures the slides are operating in sync. Start there.

Chris T said:

On this forum it has been said many times that a problem that seems to be carb related might turn out to be electric related.

Click to expand...

+1 I like to rule out ignition issues before anything else. It's straightforward, either it's right or it's not. There isn't any adjusting or 'tuning'. Start with power to the coils, or black box if it's got EI. Corroded switches, broken connectors, and the kill switch are possible problems, even if you have a charged battery. Jumper it if you have to. Find out why the timing was slipping then set it with a strobe light. If it has a Boyer check the continuity of the wires on the trigger plate, they break apart without showing any signs.

Then you can tackle the carbs, which would start with clearing out the pilot jets (again), and maybe the fuel filters, gas cap vent, leaking manifold. Maybe you could put the Peashooters back on temporarily just till you know you have a set of functioning carbs.

"I think i will try to put the slides back up and see if running richer helps." Could you explain that?

http://www.google.com/url?sa=t&rct=j&q= ... -g&cad=rja

If you know Bob at Rabers, then this isn't your first British bike, your first run in with Amals?