It idles fine and runs great! Finally

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bmwbob

bmwbob

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So my 1974 850 kept dying at stop lights at the most importunate times with Amals and Boyer ignition. So put on a Mikuni single carb. Ran great, but would still die once in awhile. So now I have a Pazon ignition, Sparks pickup, and Boyer magnet plate! Runs great and doesn't die! :D Stock system just didn't send enough juice to the Boyer!
 
Ain't it great when you get caught at a stop light and don't have to worry about stalling? I fought the a similar stalling problem for years and I came to really dislike riding the bike. Recently had the engine torn down to correct some poor work from a previous rebuild and the bike ran great on the road, but the idle was still weak and somewhat inconsistent. Based on some posts I read in this forum I decided to change the older Boyer to a Tri-Spark and the original charging system to a Sparx 3 Phase. Great idle now. It wasn't just one thing that was causing my problem, it was a lot of issues.

Now, when I roll up to a stop light, I take my hand off the throttle, flip up the shield and the bike just solidly bangs away...and I've got a big smile on my face.
 
Hopefully I'll be joining your elite group soon.My Tri-spark and CNW coil upgrade landed in the mail this morning.Probably be Wednesday before I get it fitted.New Amals and Sparx 3ph upgrade last year didnt improve much.Recent head gasket repair has also increased kickback force on startup which I hear the tri-spark will eliminate.cant wait for decent idle at a red light without dicking around blipping the throttle or adjusting the throttle stop screw on the carb.
Slainté
It idles fine and runs great! Finally
 
Ugh I've such ambivalent mixed feelings on this post, one it makes us all feel great to read of sweet road running joys, on the other hand those trying to stay factory know what they'll face again sooner or later. I've a Miki carb and Pazion on hand when I can't stand it no more either. Really truly the base line behavior of Commandos is one step down starts and steady as she goes idle with the danger being not enough rpm to protect cam or stay ahead of head light draw.
 
hobot said:
Ugh I've such ambivalent mixed feelings on this post, one it makes us all feel great to read of sweet road running joys, on the other hand those trying to stay factory know what they'll face again sooner or later. I've a Miki carb and Pazion on hand when I can't stand it no more either. Really truly the base line behavior of Commandos is one step down starts and steady as she goes idle with the danger being not enough rpm to protect cam or stay ahead of head light draw.
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I didn’t have no problem with this on a magneto ign bike.
Bear in mind that your bike is now xx years old now and the electrics might have seen better days and require some TLC, i.e. connectors require cleaning, copper wires might require replacing where corrosion has attacked them.
How many people bother with all this :?:
 
Hey I'm now in this elite group as well! yeah! I like to skite to other Commado pilots at the lights, by taking my hand off the throttle and letting her calmly IDLE.

My story involves incremental tuning, the Pazon Altair helped but was not the whole story, setting the actual fuel levels in the Amals was a long way to getting there, but the cherry on top, was using a manometer type carb balancer, I got one off eBay for BMW twins, I used to set the carb balance up mechanically to get the slides at the same heights, but final fine tuning with the balancer really gets me a smooth and stable idle, that does not change or drift.

Cheers richard
 
Bernhard said:
Bear in mind that your bike is now xx years old now and the electrics might have seen better days and require some TLC, i.e. connectors require cleaning, copper wires might require replacing where corrosion has attacked them.
How many people bother with all this :?:
Click to expand...

stockie2 said:
My story involves incremental tuning,
Click to expand...

Exactly! I'm always happy to hear about a Commando which runs and idles great. But the report of a success story in that regard is almost always accompanied by a list of the hi-tech upgrades which were done. Perhaps I'm donning my rose colored glasses here but I suspect the typical Commando, when new, ran and idled just fine. That's not to say they didn't come with built in needs (some might say "time bombs").

I'm not anti-upgrades, nor am I a purist (my points and AAU are in a plastic storage container), I just think that if a restorer pays attention to all the systems and returns them to as new condition and then adjusts carefully - and maintains that adjustment - then the original systems will work well enough to produce a decent and trustworthy idle. Temporarily (See "and maintains that adjustment" above).
 
My youth was made up of Japanese bikes that required little or none incremental tuning.when I first got the bike it felt cool to really get to know the intricacies of it but that got old getting stuck in midtown Manhattan once too often.Some guys told me that never happened years ago as they rode them all the time and suggested I didnt ride it enough but this year I've ridden the hell out of it and it just isn't reliable.Hopefully elitism is only a few upgrades away
 
I seem to have achieved it with only a change to the anodized slide and new jets. We'll see. The Pazon didn't help my idle with the bad slides. It does help it run better than the AAU which would wander around 8° or so.

Dave
69S
 
Right, Dave, I understand what you're saying. But it must be fairly pointed out that if your point plate and AAU had no wear, there would be no fluctuations. We used to set up distributors on our Sun distributor machine and the dwell and timing was rock steady on every lobe. If it wasn't, there was play somewhere. Not saying the original setup is ideal - hell I don't use it myself - just saying that IF it is right, it WILL work right.
 
Don't get me wrong. I know my AAU was worn out, heck, there was no way to adjust the points gap. It all depended on how I held my tongue in my mouth. I like the AAU because of the simplicity, I just need to find someone that will make a circular bronze shim and fit it for me at a reasonable price, but the Pazon was easy enough and probably cheaper than machine time.

Dave
69S
 
stockie2 said:
Hey I'm now in this elite group as well! yeah! I like to skite to other Commado pilots at the lights, by taking my hand off the throttle and letting her calmly IDLE.

My story involves incremental tuning, the Pazon Altair helped but was not the whole story, setting the actual fuel levels in the Amals was a long way to getting there, but the cherry on top, was using a manometer type carb balancer, I got one off eBay for BMW twins, I used to set the carb balance up mechanically to get the slides at the same heights, but final fine tuning with the balancer really gets me a smooth and stable idle, that does not change or drift.

Cheers richard
Click to expand...

Had the Amal carbs dialed in, but just not enough juice from electrical system to keep old style Boyer happy.
 
So I finished the Tri-spark and coil install yesterday.The Bike is night and day compared to when I had the Boyer.I cant believe I spent so much time on the carbs and the charging system that it was that little black box or the coils were at fault all along.My drive from Queens down to Redhook in Brooklyn in Mothersday city traffic was most pleasurable.Idle locked @ 1200RPM at traffic lights.Blipping the throttle out of habit now rather than necessity.Oh and no kickback either wearing Puma sneakers now when starting.Happy Days.
 
speirmoor said:
So I finished the Tri-spark and coil install yesterday.The Bike is night and day compared to when I had the Boyer.I cant believe I spent so much time on the carbs and the charging system that it was that little black box or the coils were at fault all along.My drive from Queens down to Redhook in Brooklyn in Mothersday city traffic was most pleasurable.Idle locked @ 1200RPM at traffic lights.Blipping the throttle out of habit now rather than necessity.Oh and no kickback either wearing Puma sneakers now when starting.Happy Days.
Click to expand...


Congrats..I also replaced the same miserable Boyer MKIII with a new Tri-Spark last month. A world of difference...the best thing that you can do with that Boyer is $hit Can it! I did...and it was a great feeling!

Are you listening Boyer?? Probably not....... :roll:
 
I'm thinking old style Boyer would be fine with Amals with sufficient juice through electrical system! I measure a little over 12V at idle on mine!
 
I've had more time on Boyer and Amals than any other combo and works fine as long as idle high enough it keeps some oil wedge on cam lobes and stays ahead of what ever electrical loads turned on. Ignition only takes 5 watts or so but does need over 10-ish for the black box brain to function w/o roughening running till stalling.
 
A good points system and Amals allows my Combat to tick over below 500 rpm but don't do it much knowing what I know now about the excessive wear and easy stalling in traffic. I don't like fast idle, who does, but realize its better to idle close to 1000 for practical reasons. I on purpose dial down idle to limp by the big twin crowd petting their crude stumbling idle souls with the soft pleasant pitter patter of even firing Norton, then about as often go WOT to send a zing through em on the power response bark and whip lash jerk off if left in gear. Cycles over 250 cc are just toys for boys so I play em as much as they or I can take. There is no other logic to apply to being a cycler over 250 cc.
 
I can't believe all the chaps on here pretending that they don't like blipping the throttle at traffic lights...Probably best to give in to old age and social pressures and buy a Gold Wing with a soft toy on the back... :shock:
 
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