Knock knock, who's there?

[Carl0s]

Yeap, yeat another whats knocking in the engine thread. Allready checked that there was no midged traped inside during the winter

So the knock, its pretty loud and you hear if you have the engine under load, and the you engine brake and give it slight thortle, just above idle (if idle tps is 10> it knocks at ~12-13tps).

Give it more, ~15tps or more the knock goes away.

I think i can clearly hear it on the right side of engine, and it sounds bit like somesort of hammering, lot more domitating and more metallic the valve tap.

It didnt do it last summer, and pretty much only thing that have changed is that i did the airbox mod. So, i assumed that its pre-ignition knock, and adjusted the maps first 5point richer, and then another 5 points, overall 10 points.

It got bit better, but not gone complitely.

Another thing that i thode was the primary chain. I can hear it sometimes kloncking when cruising in trafic on idle, but that sound comes from the left, not right.

So, should i still adjust it richer? Or start tear the engine apart?

 

[Carl0s]

update:

I checked the timing table, and something popped out... http://imgur.com/Emq8IJ6

correct me if im wrong, but those 800rpm, 1000rpm and 1350rpm @ 30tpm those 6/3/10 values pop out a bit?

Since, as far as i know 0 means 0 advance, and the bigger the value, the more advanced the timing ? That would explain why i sometimes get popping in the airbox if i pump the gas...

 

[buellxb9rs]

Was the bike sitting for a long time? Have you tried draining the gas and putting fresh gas in? Also, I wouldn't blindly modify the fuel maps. If anything do a data log while idling and revving a little then create a map. The maps and timing won't just change themselves.

 

[Carl0s]

The maps wont change, but i did the airbox mod, letting more air in the engine and by that leaning the mixture.

Ive run the bike ~300 miles after i took her out of the storage, and shes currently on her 3rd tank of fresh premium.

I did few recorded runs, but that did not realy change anything :/

 

[lawdog]

Also check the plugs (clean, not fouled, correct heat range, etc). Monitor AFR for fuel as you may get off (too rich or lean) if you start adjusting too much. Also determine if temperature plays a role as the ECM may be temperature compensating and adjusting fuel values. Still getting spark knock then pull a degree or two of timing at the rpm/tps knock area and see how it does.

You are correct. 0 is top dead center and no advance. The higher the number the earlier the spark plug fires (in degrees of rotation). Too early (advanced, higher number) and you may get knock. The higher the rpm the earlier the spark needs to fire (more advanced).

Your map doesn't look that abnormal. Here is my stock map for a 2009 XB12R.

 

[Carl0s]

Yeap, just bought new plugs, but dont know when i got the time to change them... need to run half-marathon tomorrow (whitout any pre-training) so i think the rest of the weekend goes on the bed. But, for the plugs, had epiphany that they may be in need of change. Always thode that i dont need to change 'em since the previous owner had just changed new OEM plugs before i bought it.... and that was 3 oil changes ago...


Just my 2cents, but for me it would sound more reasonable that close to idle you got 0 or even retarded timing, increasing the low end percistence. And the thing that first on the map you got close to 0 advance, and then it jumps all the way to 10... But, i gues i know more after ive changed the plugs, maybe i even throw in the "stock" racemap and just dedicate one evening to ride around whit the laptop to get it tuned... It justs, for me feels bit "lame" to tune whit the narrowband, since its constantly jumping between rich & lean... :/

But just did ~200mile ride today, and im starting to feel confident that it has something to do whit the maps / advance / ignition, since if you "tease" in the right moment you can make it backfire to the airbox... and only way that is happening is that the mixture combusts while the intake valve is still open. :/

 

[lawdog]

Well my personal opinion is the narrowband o2 sensor is worthless. Too lean for air cooled motors. I like running richer at 13.5-13.7 cruise and around 13.2 WOT. You take a small hit on fuel mileage but the throttle response is like no other and pulls like a freight train. I tune it like a air cooled Harley motor verse a water cooled engine at a leaner mixture. There has been good discussions about the use of a richer mixture as a cooling agent (cruise range) but I have read some mixed opinions. My personal experience is with a richer mixture my headers no longer glow and I feel less heat between my legs. No scientific methods to back up my personal observations though. Also noticed less lag on roll-on full throttle response. But on this board I am in the minority here and most tune using the narrowband and run the leaner mixture at cruise. If I ever get around to it I want to tune my exact cruise a little leaner (14-14.5) and then step in richer above and below. I plan on yanking the headers and installing a bung and getting them coated next winter so it won't be for a while. I only wideband tune on the street based on feel.

If you feel comfortable why not pull a little timing at that tps/rpm that you are having problems with. Too lean and off timing will cause that backfire.

 

[Carl0s]

Well, some updates.

Today i did a oilchange, and while had the bike up for maintenance decided to change the plugs and change the map also. At the point where i pulled the old plugs out, it was pretty clear that there is a problem whit the mixture. Front plug was all white, and rear plug all black.

I got the custom xb12 map from https://sites.google.com/site/ecmspy/ that i adjusted 4 points richer. And then did recorded run... (https://docs.google.com/file/d/0Bx0YC44JNfBVellJYXN0aFZlX00/edit?usp=sharing)

And for me, it looks like the o2 is bouncing a lot? :/

 

[buellxb9rs]

The o2 will bounce around a lot, are you recording with the open learn enable turned off? If not, data logging will do no good. You will just be chasing the o2 sensor all over the place.

 

[Carl0s]

Yeap, i did uncheck the "Open loop learn" before logging, what cause me wonder if my lamda is goner? From witch i had an idea, my friend has currently one "spare" PLX-AFR ( http://www.plxdevices.com/product_info.php?id=SEMOSMAFRV2 ). if i plug that one in, use the narrowband emulation for the buell ECM and take the logging from that?

But, anyone know if / how i get the TPS and RPM input for the PLX, and, if the special USB-3.5mm cable that it needs, can be home-made from the buell ECM cable ?

 

[Carl0s]

Well **** me sideways... Some dipshit decided to steal my bike while i was at work today, so i think there comes the cloasure.