Lean rear cylinder
randygrein at comcast.net
Fri Oct 2 06:16:12 PDT 2009
There is a jetting differential front to back, can't remember for sure
which way - but sounds like you need to go up a size on the rear.
Randy Grein, WMRRA #141
On Oct 1, 2009, at 10:04 AM, Ernest Montague wrote:
> My rear cylinder is running super lean for some reason. The header
> interior is clean and light grey/white with no carbon. I am running
> pump gas, which always leaves my headers a bit black. But the rear
> is very light colored, the front the normal blackish. It's not a
> head gasket leaking water ( at least last time water got in the
> combustion chamber via head gasket it steam cleaned everything. The
> chamber just looks lean, valves very clean and grey/tan. I looked
> for missing vacumn plug, bad slide rubber, plugged main jet, etc.
> The mains front and rear are 170s a range that has worked well in
> the past with the M4 system and BMC big mouth race filter (factory
> pro design). Even if it was the main I can't believe it would be
> so different from front to back.
> Also backfires and pops at cruising 2500-4000 rpm.
> Bike is mostly ridden at full throttle on the track.
More information about the SV650