https://www.cycleworld.com/story/bikes/kevin-cameron-explains-how-to-tune-carburetors/

In my head, mr72 is Kevin Cameron

Interesting article but like many other I similar ones I read on the net the most important consideration has been missed.

Carb tuning is totally pointless if the internals ie: slides, guides, needles, springs, plungers, pivots, linkages etc ........are worn or damaged 

Quote from: Bluesmudge on May 18, 2022, 09:12:45 AM
In my head, mr72 is Kevin Cameron

James Cameron ? Who is Kevin Cameron No idea.
Cool.
Buddha.

Quote from: Bluesmudge on May 18, 2022, 09:12:45 AM
In my head, mr72 is Kevin Cameron

LOL

It should be made very clear: my experience is solely limited to the 5 or 6 motorcycles I have worked on. I am no expert on motorcycle carb tuning.

And remember my own GS still has a lingering issue that I have yet to sort.

Quote from: The Buddha on May 18, 2022, 10:37:30 AM

Quote from: Bluesmudge on May 18, 2022, 09:12:45 AM
In my head, mr72 is Kevin Cameron

James Cameron ? Who is Kevin Cameron No idea.
Cool.
Buddha.

He is a long time contributor to Cycle World. He is a tottal engineering, aviation, and motorcycle nerd who writes a lot of slightly self indulgent articles that attempt to add romance to complex engineering concepts.
Mr72 is like our own personal store-brand version of Kevin Cameron. Maybe James Cameron too. They all give off similar vibes.

Store brand!! I love it!!

He's store brand of James Cameron !! Gotcha. A 3d GS500 hits an iceberg in its maiden voyage while carrying 5000 hollywood celebrities, and blue haired old ladies jump out and attack with harpoon guns then get on GS500 powered jetski's and Leonardo Di Caprio and fat chick cant fit on GS500 and he falls off and sinks.

Mr72, now make that movie, it will beat all the woke a$$ garbage out there. I'll pay $20 to see and even buy crappy popcorn wait a sec, the popcorn is the best part.

Cool.
Buddha.

He is a long time contributor to Cycle World. He is a tottal engineering, aviation, and motorcycle nerd who writes a lot of slightly self indulgent articles that attempt to add romance to complex engineering concepts.
Mr72 is like our own personal store-brand version of Kevin Cameron. Maybe James Cameron too. They all give off similar vibes.
[/quote]

Thats all true but Irrelevant  , what really makes him famous is all the two stroke Superbike racing he did in the 70's. He prepared some amazing bikes.

Back to the original point, one thing (which we can't really do) that was brilliant in this post was about determining if it is rich or lean, which can be pretty tricky in transient conditions, is to turn off the petcock and if the problem gets worse, it was lean, and if it gets better, it was rich. That's worth the time to read that article right there.

I guess I just appreciate someone who is logical and takes time to explain how things work.

You can use the choke for the same thing

I don't think you can use the "choke" on a CV carb the same way. Certainly not to tell if it's too rich in transient conditions.

Petcock off reduces fuel without changing airflow or vacuum at all and under all operating conditions. You don't have to have the thing set too rich for the choke to make it run worse when the engine is hot. It will always run worse with the choke on, depending on the RPM, unless it's cold. Plus due to running the idle way high, the "choke" will completely mask any running issues at idle or low rpm/low-throttle. It'll always idle faster with choke. That doesn't mean your idle is always too lean.

Yeah, that's the point, if it's running too lean a little bit of choke will make it run better.

but if it's rich, a little bit of choke will also make it run "better", if measured in idle speed.

I think there's no way to add choke in a small enough increment to tell whether the needle needs to be shimmed or you need to jet up one notch part throttle.

There is no "off" on a GS500 petcock so I guess you could just pinch the fuel line. I do like that idea. Especially since modern gasoline makes it difficult to read spark plugs to determine if the bike is rich or lean.

Almost the only way to tune a GS is to
1. Mark throttle position on the grip and switch.
2. Bolt an O2 sensor into the exhaust and wire it to a digital voltmeter (DMM) and put it on your tank.
3. Ride in all weather situations keeping an ey on the DMM and the throttle position.
4. Make your calculated adjustments and repeat.

Cool.
Buddha.