detonation

[Guest Lovell]

I AM A NEW MEMBER, HAVE A 2002 V-11 LEMANS, BIKE HAS 2300 MILES ON IT. UNDER HARD ACCELRATION I CAN HEAR THE ENG. DETONATING, BACK OFF THROTTLE NO NOISE, BIKE IS STOCK BUT HAS A FREE FLOWING MUFFLES ON IT . BUT IT DID THIS BEFORE THE EXHAUST CHANGE. ANY IDEA? ALWAYS RUN HIGH TEST PUMP GAS. DONT WANT TO DAMAGE ENG. SO JUST CRUISIN FOR NOW THANKS OF ANY HELP OFFERED.

[twhitaker]

Hi neighbor.

 

Our bikes do not care for hard accelleration below 5000 RPM. Doesn't hurt them a bit to downshift to get that 5000 mark.

[robbiekb]

i'm a little confused by the term "detonation" ? I frequently ride my V11 in the higher rpm ranges where the engine finally feels like it's starting to pull ( I call lit "wailing banshee mode" **grins**) and haven't experienced anything that i would call detonating.

 

With the k&n pods on my bike I have had issues with backfiring when i back off the throttle after some "spirited" riding when it's warm out - one time last year i blew the throttle bodies completely off when i closed the throttle!

oops !

[al_roethlisberger]

i'm a little confused by the term "detonation" ? I frequently ride my V11 in the higher rpm ranges where the engine finally feels like it's starting to pull ( I call lit "wailing banshee mode" **grins**) and haven't experienced anything that i would call detonating.

 

With the k&n pods on my bike I have had issues with backfiring when i back off the throttle after some "spirited" riding when it's warm out - one time last year i blew the throttle bodies completely off when i closed the throttle!

oops !

 

 

....sounds like you need(needed) your air/fuel mixture reset after your intake and exhaust mods. A lot of us have had the intakes blow off with a cough back through the intakes when the mixture was off.

 

 

WRT to "detonation" or commonly known as pinging, the MG combustion chamber is notoriously "bad", rife with hotspots, an inefficent placement of the plug, and a poor squish-band.... and often is susceptible to pinging under hard acceleration and hot conditions.

 

If this is a recurring problem for you, and yes it can cause damage....you can address all of these through porting, dual-plugs, different pistons, etc... but simple fixes are to use high octane fuel, get the air/fuel mix tuned, and possibly use a cooler plug(as long as that doesn't cause other problems).

 

This is often more pronounced after changing intake and exhausts to freer flowing units.

 

Also, as mentioned, not "lugging" the engine below 4-5k under acceleration helps a lot. Keep it spinning

 

al

[robbiekb]

Hi Al,

 

This actually raises a good point about the lack of a PCIII tuning center in the Seattle area. I'm on my 3rd computer (the first two died for unknown reasons) and the map was tweaked by Micha so really although i know its running rich, I don't have much of a reference point for how my bike should run to obtain optimal performance

[Motomonster]

Here's a PC tuning center in the Seattle area:

 

http://www.soundrider.com/Dealers/SCS/Default.htm

 

Last time I talked to them, they'd do a Guzz.

[rossoct]

Lovell, My 01 Rosso made some unusual noises (pinging/valve float type).It did this after I changed to a FBF lidless air, Stucchi X-over,FBF carbon ovals, however after I had the ECU remapped all this went away, I surmise that it was WAY lean. Waiting for JohnT to get his dyno setup and add a power comander then we'll really rip.Good Luck! There's plenty of talented people on this forum to give you tips.

[Guest Bruce]

My '00 Sport pings under the right conditions and the plugs are indicating rich over all. I've wondered if maybe there is some carbon build up which causes premature ignition or if the electrical timing is off. That is the computer thinks the engine is accelerating faster than it actually is and advances the timing too quickly. So changing the f/a ratio or the spark plug temp range might minimize the symptoms but not fix the actual problem.

 

My experience is with carbs which I recall use an accelerator pump to boost fuel intake when you open the throttle plates. When the pump is shot there would be a huge lag is you opened the throttle plates too fast. My bike feels a little like that, a little balky when it pings. So as soon as it stops raining around here I'll be doing some tuning to see if it has any effect.

[Guest Lovell]

THE NOISE (DETONATION) HAPPENS AT HIGHER RPM,S WHEN I AM REALLY RINGING THE BIKE OUT, MOSTLY BETWEEN "S" TURNS AFTER DEACCELERATION,THEN FULL THOTTLE UP THOUGTH THE GEARS(6000-UP)TO RED LINE.DEFINENTLY PINGING. ANY ONE TRIED RACE FUEL MIX IN THIS ENGINES? LIKE TURBO BLUE? AND HIGH OCTANE PUMP GAS?

[docc]

It sounds like you need to be flowing more fuel. The old tub of an engine likes the cooling of fuel flowing over the valves.

 

Check your TPS setting and be sure the throttle bodies have perfect balance in the 3000 rpm range.

 

My 2000 Sport was really fuel sensitive until I got all the tuning squared away.

[dlaing]

It does sound like you need more fuel.

At Wide Open Throttle a little imbalance or TPS being off, should not make a big difference.

If you get a PCIII, there are four major advantages,

1) you reduce overly lean conditions that can cause burnt valves and detonation.

2) you reduce overly rich conditions that may lead to detonation from carbon build up.

3) a little more power

4) better rideability.