PSA: Agostini Silencers

[JeffOlson]

A while back, I bought an Agostini silencer for my Norge. In a nutshell, if I could go back and do it over, I would just say no. It turned out to be an expensive experiment.

While the Agostini silencer looks good, at least when new, it does not fit the aesthetics of the Norge. It is too small. It is also oval, not round, and it sits at an italic-like angle when hanging from the exhaust hanger extension needed to clear the panniers.

It gets worse.

The can is hung by a rubber-backed metal strap, and the rubber melts when the can gets really hot like it did today. Further, the pipe at the front of the can turns blue when it gets really hot like it did today.

Finally, with the DB killer in place, the can is quieter than the stock silencer. With it out, the sounds is glorious, but the engine can run a bit rough at times. This afternoon, it ran terribly rough--it felt like it was running on one cylinder, with constant back-firing (not mere popping on deceleration).

Back to stock tonight. My advice: don't waste your money.

[Vasco DG]

If it feels like it's running on one it probably is. Have you checked the plug caps for arcing?

Pete

[JeffOlson]

No, I haven't. Good idea.

When I found a safe place to pull over this afternoon, I stopped the bike and popped the DB killer back in. Upon restarting, the bike ran great. Very odd.

[beetle]

Not odd at all. The 8V is very sensitive to changes in the inlet and exhaust. Did you pull the main fuse to reset the trims?

[JeffOlson]

^ No. I'll do that today. Thanks!

[rodekyll]

Hey Pete -- is this an example of exhaust backpressure making a difference?   ???   ~;

[JeffOlson]

Just FYI, I swung by my dealer this morning and had them install a new gasket on my stock can. (I wrecked the original one trying to put the stock can back on.) They hooked my bike up to their computer, reset things, and noted that the ECU stored fault codes for getting really hot yesterday. (Fortunately, the bike seems no worse for the wear.)

They were surprised to hear about the Agostini can causing problems with the DB killer removed as they have several customers who have installed them on different bikes (but not all with the same motor that my Norge has).

So, I am back to fairly quiet stock, with the usual snatchiness to the throttle. Time to try Beetle's Norge map!

[Loftness]

For what it's worth the V7 version is truly glorious.  We haven't had a customer do anything but love theirs.  I'm an owner myself.

[JeffOlson]

^ That's what I understand. Perhaps the V7 motor is less sensitive than the Griso/Norge/Stelvio motor. If so, that's a great thing! I dislike sensitive motors...

[JeffOlson]

It's really the rubber that kills me. Who knew that rubber melts when heated?

[Vasco DG]

The blueing of the muffler pipe and melting of the strapping are throwing up big, red warning lights to me Jeff.

There are plenty of people using Agostini and other pipes that use such a mounting arrangement without issues and it really makes me suspect that there is something amiss with your machine, especially given the poor running.

My first suspicion would be plug cap arcing to earth. This doesn't only affect performance but the fuel that isn't being burnt in the engine will be pumped through and will end up combusting in the catalytic converter. The blue pipe and melted strap on the muffler are suggestions that this condition may be occurring. The excess heat alo is a giveaway.

Next, you said the shop 'Cleared the errors'. Do you know what errors these may of been? We're they active or memorised Lamda errors by any chance?

Pete

[canuguzzi]

Pete, are the errors retained in memory anywhere even after they are cleared. In some cars a history is retained even after clearing active errors. I have yet to see an error in the Norge so I have no reference.

[JeffOlson]

Pete, thanks for advice. If I recall correctly, they were memorized lambda sensor errors. I will check with TJ, the mechanic at the shop, to confirm. I will also mention the arcing possibility.

Yes, there was definitely something amiss, running on one cylinder and backfiring like there was no tomorrow, but it was just that one time, for just a few miles. I'm going on a long ride tomorrow. I will see how she does...

[Vasco DG]

Well if a plug wasn't firing and fuel/air was being pumped out uncombusted it's going to play merry-hell with the Lamda signals. Then there will be the ongoing combustion elsewhere in the exhaust system. The whole thing will be guaranteed to screw up the fueling and make the machine run like a pig. I'm surprised it didn't throw an error if it's what I suspect.

Look, it may well be something else but I don't believe that the pipe per-se has anything to do with your current problem. More importantly though re-mapping a bike with a pre-existing problem will achieve absolutely nothing apart from further muddying the waters.

Get your bike running well in stock trim. Then look at improving it. Don't look for a magic bullet. There isn't one.

Pete

[JeffOlson]

If I may ask another question, what would cause such a thing (arcing)? If not the occasional running without a DB killer, then what? The bike is new (or was until I began abusing it). It has largely been running very well, even without the DB killer on occasion as the mood would strike, with only occasional and limited rougher running (but nothing like the crap running the other day).

[Vasco DG]

Damage to the plug caps during their removal. They are very delicate and easily damaged.

Another issue may well be the fact that you have been running the bike with and without the dB killer in it. Every time you change the pipe characteristics the ECU will try to re-trim the fueling to suit but this takes time, especially if the trims aren't zeroed when the change is made.

Pete