Afterfiring - inconsistent but persistent

[Chuck in Indiana]

Norman.. I was just on the phone with Dusty, and we were knocking this problem around a little. I'm still thinking it's a sensor telling the computer it's too cold. While GuzziDiag will tell you that, if it were me.. I'd get a can of Caig DeOxit, take all the electrical connectors apart at the sensors, etc.. give em a squirt, put em together, wiggle them around, oh..you know.  Maybe it's just corrosion. Dusty mentioned the center muffler maybe clogged? The colonoscopy bag is a fairly restrictive muffler. Maybe a mouse decided to set up housekeeping? It's going to be something simple..

[John A]

Norm said miles per gallon went from 40's to 30's on the trip back home when he first got it.  if he rides slow it may not rule out a mouse nest but it points more towards a sensor input,  I think

[normzone]

Chuck, on my model the PO upgraded the center muffler to a bi-direction reflux system, so what used to be central exhaust gases now flows out with the left and right systems.

[oldbike54]

 ^^^So you're saying it has heartburn ?

 Dusty

[normzone]

^^^So you're saying it has heartburn ?  Dusty

Well, the plugs have always looked like they burn clean and lean ...

[John A]

Well, the plugs have always looked like they burn clean and lean ...

late timing

[Tom H]

Norm, do I need to come down there and rough up your bike

Are you sure about the current mileage? Did you ever ride it for a known distance like to work or wherever?

At Henshaw, I did not notice an excessive smell of gas and it seemed to start and idle fine.

Tom

[normzone]

Thanks [Tom H] - anytime you want to come down and slap the Bassa around a little bit just let me know and I'll make room for you in the spare bedroom.

Actually, that's all I do, ride to and from work when I am working.

Since the speedo is dead at all levels, I google maps my rides and track it all in the logbook. Not supremely accurate, but close enough for an audit.

There's an outside chance that the Jackal speedo I'm swapping to soon may actually work.

[Chuck in Indiana]

<tearing hair out> Aaaaaghhhh, you don't actually *know* what mileage you are getting??

Two demerits.

[Vagrant]

I assume it's the small computer. If so it's the cam position sensor and or the tps. If the tps fails in hot weather / under load i feel the bike goes into limp home mode until the battery is disconected. I bet the tps is done for. Still a good idea to replace all relays if you haven't yet. If so clean and spray as suggested.

[normzone]

<tearing hair out> Aaaaaghhhh, you don't actually *know* what mileage you are getting?? Two demerits.

Your honor ... May I please address the court?

Somebody said that a man who represents himself has a fool for a client. I'll not deny that.

But the initial data was developed back when I still had not only a functional analog speedometer, but also an odometer AND a trip meter.

We need not even mention the once proud tachometer, manufactured by the legendary Veglia Borletti, known round the world for accuracy, precision, and ... reliability.

(uproar in the court)

Your honor, please strike my last sentence from the record.

Then, as first the speedo, then the odometer, and lastly the trip meter gave up their humble mechanical lives in the defense of ... well, they gave up ... I was compelled to resort to estimation.

But not just ANY estimation, your honor, but Computer Aided Estimation (CAE). Why, even aircraft pilots have been known to rely on this tool.

I rest my case, your honor. If the demerits must stand, so be it.

But you, the jury, should think on this one thing ... Those demerits were assigned using A COMPUTER.

[Chuck in Indiana]

  Good stuff there, Norman.. 

[normzone]

Thank you.

So ... about those demerits.

Are they permanent? Do they drop off in ninety days or something?

Is this going to prevent me from getting a ... pay raise? Or a revenue sharing check? Or a cold beer?

[John A]

its a stain that will follow your descendants for generations.  its almost as bad for me, its said I cant even tune a gasoline engine. Us Bassa owners have a secret sect.  the way you weaseled out of that one makes you one of us   

[Tom H]

I was just askin'.

For instance my EVT with city driving only went 96 miles with 3.2 gallons. I'm pretty sure I filled it to the spot I always stop at last time. When I did my commute of mainly freeway driving, it used the same amount and went 120 miles (mileage had a variance of 5 miles with 5 bikes and a new truck. Distance could change slightly with the same vehicle).

Tom

[normzone]

its a stain that will follow your descendants for generations.  its almost as bad for me, its said I cant even tune a gasoline engine. Us Bassa owners have a secret sect.  the way you weaseled out of that one makes you one of us

Very cool.
Is there a secret handshake or something I need to learn?
Can I add " a stain that will follow your descendants for generations " to my tagline?
EDIT: REMOVED MY REFERENCE TO POLITICS JUST IN CASE -

[Tom H]

I bought the bike and was dismayed to get forty couple mpg on the first tank leaving Tucson for San Diego, and it went down to the low thirties shortly thereafter, then settled in the high twenties where it has performed for the last couple of years.

Norm,. on the mileage. 40mpg on the freeway would be normal, this is what my EVT gets. I mentioned this already, now that I'm not doing my freeway commute and now driving the city streets with a traffic light at every corner (at least it seems that way), I think my mileage is about 30mpg. I'll check again when I use up this tank. My HD used to get 40mpg, now it's about 30 as well. The fuel light used come on at about 125 miles, not it's about 95 miles of city.

The popping on decel.... I would really be looking at your exhaust system as other have mentioned, I would also check the intake rubber boots for cracks. Then move on to fuel and ignition.

You mentioned the soot on the exhaust tips, my EVT get a dry soot  as well. Not much, but it get on your finger




Tom

[normzone]

Tank off and the sun is going down.

Brought it home hot and played unlit propane torch at all the exhaust connections ... boring.

Will do valves, plugs, air filter and Jackal dashboard in the AM.

Chuck, you and others have mentioned sensors.

Whats that unimportant looking lump about the size of three beans mounted on the inboard side of the starboard bracket that the big rubber tank mount bushing mounts to - two wires to a connector fitting, color code purple and the other red/white ?

I don't know if it's a sensor, or whatever, but it's there and I've never changed it. Never heard any talk about it either.

Good stuff there, Norman.. 

If you ever need legal representation I'm looking for opportunities to practice.

Thanks TomH - old intake boots with known cracks have been replaced when clutch work was done - I'll check all exhaust joints in the AM

Beer thirty now 

[John A]

that is the ambient air temp probe.
as for the secret handshake, its a secret. in other words: we forgot what it was

[normzone]

AMBIENT AIR TEMP PROBE ?

How the hell can I test it?

Is it readily available someplace?

[antmanbee]

I'm pretty sure air temperature is one of the items you can select in Guzzidiag to monitor.

[Kiwi Dave]

AMBIENT AIR TEMP PROBE ?

How the hell can I test it?

Is it readily available someplace?

This might serve useful.

https://www.dpguzzi.com/efiman.pdf

[beetle]

Yes, you need to get GuzziDiag connected, you can see data from all the sensors. 

On a cold engine, the air temperature sensor should be within 1 or 2 degrees of the engine temperature sensor. Both should be close to ambient. Any wild variation should condemn the sensor.

[normzone]

I changed the engine temp sensor long ago, with brass connector upgrade.

It's somewhat under 80F here, and the sensor reads 3.47K ohms - that seems about right based on the elfman pdf chart, but GuzziDiag will tell the tale I guess.

Waiting update from my local benefactor on that issue ...

[normzone]

I have a GuzziDiag date Sunday at 4:00 - I figure casual dress, no pressure since it's only the second time we're meeting, and I'll pay.

Going for a test ride now. All I really accomplished today was  plugs, valve, air filter, and getting mosquito bit all to *^$#, but that and some fuel injector cleaner in the gas is still a good thing.

[Muzz]

 

[normzone]

The afterfiring is still there, Muzz - I found no exhaust looseness when I checked the joints.

Aaron is on his way over now.

[wirespokes]

How come these new computer controlled bikes get such awful mileage??? My old LM4 gets somewhere between low 40s to almost 50 - no computer, just Dellortos with accelerator pumps.

Have you contacted the previous owner about this? Perhaps he can shed some light on the issue - when it started, what was going on. Maybe there IS a mouse nest in the muffler.

[Tom H]

How come these new computer controlled bikes get such awful mileage??? My old LM4 gets somewhere between low 40s to almost 50 - no computer, just Dellortos with accelerator pumps.

On the MPG. Take your LM4 and add a National Cycle HD police style shield, saddle bags and a trunk and then ride it down an interstate at 70-75 MPH and see what you get. Then do the same on a city street that you stop at every block.

If I pulled my shield, bags and trunk off my Eldo and added civi bars and tuned them upside down and put rear pegs instead of boards so I'm in a tuck, I could probably get close to 50mpg on the freeway.

JMHO. if I lived in a place that I could ride at about 50 mph for miles at a time without a traffic light, I could see 45mpg out of my Eldo and Ambo. My EVT is heavy, not sure what I would get. Norms Bassa is a fairly heavy bike.

Tom

[normzone]

Update:

I changed air filter, plugs, and adjusted the valves.

Valves were only oversize .001 - .002, so I'm discounting that.

Plugs were evidently rich, but again I'm viewing that as an effect, not a cause.

The air filter did look sad, I'm going to go back through the logbook and see if I skipped a scheduled change.

After getting a new air filter, plugs and valve adjustment it does afterfire less, but it still does it.

I found no evidence of exhaust leaks, and opted not to change gaskets / nuts.

My benefactor Aaron and I tinkered with Guzzi Diag, and after a couple of false starts got the laptop and software to admit that the Bassa did indeed have a .bin file running on the P15, and we saved it to the laptop and my thumb drive. I also have a map Beetle provided - I'm thinking I need to acquire a viewer that will allow me to compare the two files and see what kind of deltas there are, if only for educational purposes.