Popping on Deceleration

[Cool Runnings]

Cool Runnings, the map for the Norge works.

NP, I see that, might have to bring out 'the box' (no lap dance top device) to the garage after getting me one of those noise makers. 

[lucky phil]

Popping with the 8V (assuming no air leaks or other freaky things) can be cured by adding fuel to the map between 2500-3500 RPM in the 4.6-5.2 TPS range. The extra fuel cools and floods the zorst enough to quench the pops.

Not really, one of causes of popping in the exhaust on the overrun is due to unburied fuel in the exhaust system due to incomplete/slow burn in the cylinder continuing in the exhaust.
This incomplete burn can be caused by a lean mixture (a lean mixture burns slow) Richening up the mixture at in the effected range actually results in a complete/normal burn in the cylinder which eleviates the issue.
Nothing to do with flooding and cooling the exhaust.
Ciao

[canuguzzi]

My stock map didn't exhibit any popping on decel, ever. The modified map does.

[beetle]

Not really,

You're quite right of course. I plead the beer defence.




In this case I was referring directly to the map Jeff is using. The fuel is cut on a closed throttle at 8500RPM/TPS 6.0 down to somewhere around 2500/4.7, causing a lean condition and thus the popping.

The rest is poppycock.

[scra99tch]

I had it on my vintage.  With tuner pro I upped my fueling at the point it started 3800 to idle.  It is completely gone with maybe a slight burble if anything.  I'll re adjust becuase idle is a bit higher.

[rocker59]

What causes it? What can be done to reduce it?
 

It's a lean condition on idle.

Either there is an exhaust leak, or the idle mixture is too lean.

If not an exhaust leak, then richening the idle mixture is the answer.

[JeffOlson]

I have loaded an updated map with a bit of "no-pop" added to it. I hope to give it a lengthy workout tomorrow on a long trip for business and will report back (assuming the rain holds off tomorrow, as I need to dress up for work and would prefer not to have to worry about wet gear tomorrow).

[JeffOlson]

UPDATE: The new Norge map with anti-pop is awesome! Thank you, Beetle!

The Norge runs like a different bike. Power everywhere, no bucking or lurching, no audible popping on deceleration. The engine doesn't mind lower RPMs now, and it races forward smoothly as the RPMs climb like my old Ducati ST2 did. I am happy! (Too bad motorcycle manufacturers cannot get away with making their bikes run properly from the factory, what with emissions controls...)

I am going to ride to Eugene and back today from the Portland area and give it more of a workout, but after 20+ miles this morning, I feel like a have a new, smoother, and more powerful bike.

[Cool Runnings]

Very cool.

[JeffOlson]

I put 200 miles on my Norge today with the new map. Very nice! My previous assessment still holds--and I got 42 MPG keeping up with traffic at 75-80 MPH...

[Cool Runnings]

I put 200 miles on my Norge today with the new map. Very nice! My previous assessment still holds--and I got 42 MPG keeping up with traffic at 75-80 MPH...

I need a fancy slip-on exhaust first. 

[JeffOlson]

I need a fancy slip-on exhaust first. 

I, too, think I need another Agostini "silencer." Yesterday's ride was wonderful but too quiet. I really could not hear the exhaust on the freeway (but I could hear wind and tire noise--ugh!). After an hour of this, I really started wanting to hear my old Agostini can. I really thought I would be happy with the stock exhaust as it has a nice rumble to it while idling, and it is a bit louder now than it was when new. Now I'm thinking I need it to sound like this again:

https://youtu.be/FOHq50AMrpY

Oh, and I would need the compensator eliminator y-pipe, too.

[Cool Runnings]

I need a Agostini for Stugris 2016! 

Wonder how many Gooses I'll see?

[Cool Runnings]

Jeff, does the Norge 8V use (5AM ECU) or (15M/15P/15RC ECU)?

[JeffOlson]

Jeff, does the Norge 8V use (5AM ECU) or (15M/15P/15RC ECU)?

We have the 5AM ECU.

[Cool Runnings]

Thx...