Pinging from left cylinder head?

schrader7032 · Post by **schrader7032** » Mon Mar 12, 2007 2:46 pm

Well, if it's only one side, that would tend to rule out ignition advance. You could possible be running very lean on the left side so performing a carb overhaul or a check of the settings might be in order.

What about the compression, left versus right? You might have some deposits built up in the left combustion chamber that's contributing to higher than normal compression. The R69S ran 9.5 to 1 compression as I recall.

Kurt in S.A.

Bruce Frey · Post by **Bruce Frey** » Tue Mar 13, 2007 3:27 am

Are your carb flanges tight?

Ciao,

Bruce

Darryl.Richman · Post by **Darryl.Richman** » Tue Mar 13, 2007 8:44 am

Are your carb flanges tight?

...and FLAT? Don't overtighten the flanges, or they won't be flat for long. Someone may have done this for you already.

Are you sure it's a ping and not, say, a ticking or a knock?

wicks · Post by **wicks** » Wed Mar 14, 2007 1:38 am

Definitely not a knock. That krinkly little valve noise that sounds like there's ball bearings bouncing around in the head (only at low RPMs when giving the gas).

The flange - is that the top of the carb that screws on holding the cable/plunger mechanism?

schrader7032 · Post by **schrader7032** » Wed Mar 14, 2007 7:09 am

The flange is the oval-shaped fitting that bolts to the intake port on the head. It should have two holes in it, top and bottom, which mate with the two bolts sticking out of the head. Read the following about the flange:

http://www.w6rec.com/duane/bmw/flange/index.htm

Kurt in S.A.

VBMWMO · Post by **VBMWMO** » Mon Feb 15, 2010 2:51 pm

Anyone with an idea why the left cylinder is pinging at lower RPMs? Bike is pretty low mileage - 12K miles...

How to I make it quiet down? Thanks for any tips.