Mild pinging under load @ low rpm. Cause?

[GelandeStrasse]

Hey folks
My GK is running like a champ except for some mild pinging when the throttle is opened at low rpm when under load like up hill, two up + luggage. Simply put - if I lug the motor. No problem if the rpms are higher or I choose a lower gear. Apart from this little issue it goes like the clappers if I open the taps, no pinging or hesitation just snarling hard addictive acceleration to the red line. Which is nice.

Where should I start my diagnosis then? I'm guessing a fresh carb sync will help but is that the root cause?


Please, I'm looking for knowledge on the general causes of pinging rather than the usual snaps about synching carbs, valve clearances etc which I'm very much aware of

Thanks in advance

[Steve]

Carb sync won't do anything for pinging.

Pinging is when the mixture is lighting before the spark sets it off.

Causes of pinging are: improper ignition timing, low-rpm running at heavy load, improper octane rating, improper fuel mixture.

If you have done all the basic maintenance, you will have proper fuel mixture and ignition timing. These bikes are made to run on low-octane fuel, but your running conditions might dictate a bump up to the next grade, on occasion.

In the meantime, the easiest solution is ...


DOWNSHIFT.

.

[dorkburger]

My 1150 has always pinged slightly when the engine is lugged. It also needs premium fuel, or it becomes unhappy. I've often wondered if the pods, and their location behind a hot engine ( hot intake charge ) contributes to this.

[tkent02]

Exessive carbon in the head can cause pinging too.

Riding like an old lady does these bikes no good. Wind it out.

[GelandeStrasse]

Thanks for the suggestions guys.
So, I need to stop riding like granny and try treating it to some high octane fuel. I think I can manage that!

GSR is the pups nuts

[chuck hahn]

You can water clean the cylinders too.

Get the engine good and heated up with a fan in front of it. Slide the airbox back and run up the RPMs and squirt water into each carb intake. Keep the throttle up as the water will try to stall that cylinder. Keep it running and give each cylinder 4 or 5 good squirts with a spray bottle.

The concept is the same as if you put water in a hot skillet do deglaze it..except you are now deglazing the piston and valves.

Now that the cylinders and valves are carbon free, redo the vacuum sync and recheck the timing.

[GelandeStrasse]

You can water clean the cylinders too.

Get the engine good and heated up with a fan in front of it. Slide the airbox back and run up the RPMs and squirt water into each carb intake. Keep the throttle up as the water will try to stall that cylinder. Keep it running and give each cylinder 4 or 5 good squirts with a spray bottle.

The concept is the same as if you put water in a hot skillet do deglaze it..except you are now deglazing the piston and valves.

Now that the cylinders and valves are carbon free, redo the vacuum sync and recheck the timing.

Learn new stuff all time! Never heard of this method to de - carbon. Somewhat easier than disassembling the top end!

[LarryJ]

mine does the same thing(3-5k rpm, 85F+) Tried 89 octane, no change. I was advised to just change out the intake boots. Have them on order from Z1.

[LarryJ]

I suspect many will benefit from the actual cure. When changing the boots, I'm voing the give the water spray a shot too.

[chuck hahn]

GelandStrasse,

Have you ever replaced a blown head gasket on a car? If youll notice the cylinder ( or cylinders ) that water has leaked into are as spotless as the day they were made..this is from the water and coolant deglazing the cylinders. Lots of blackish carbon crap will come out of the pipes, so I advise doing it outside.

[Steve]

Thanks for the suggestions guys.
So, I need to stop riding like granny and try treating it to some high octane fuel. I think I can manage that!

GSR is the pups nuts

Try some higher RPM before you waste your money on needless octane.

By the way, what RPM were you running when you noticed the pinging?

.

[LarryJ]

it occurs in the 3-5k range, under load.

[GelandeStrasse]

Try some higher RPM before you waste your money on needless octane.

By the way, what RPM were you running when you noticed the pinging?

.

Silly low, like 1500 - 2000. I think it's just my riding style, gained from my time riding a large capacity twin that didn't bog down even pulling from below idle rpm.
Still, now I have the perfect excuse to accelerate hard a lot

[Big T]

There's nothing wrong with your bike

Never ride it at less than 3k rpm

[boingk]

Bingo. My 245ci 6cyl Chrysler Valiant can chug along with those rpms, but these bikes are happiest north of 3 or 4k.

- boingk