So got one today, did some readings. Unit calibrated as per manual to show 2% in normal air. So at idle of 1200 Right pipe: Between 7.0% & 8.0% but mostly sticking to about 7.7% Left pipe: Between 6.5% & 8.0% but mostly sticking about 7.5% At 3k RPM Right pipe: Between 6.3% and 6.5% Left pipe: Between 5.0% and 5.1% At 4k RPM Left & Right pipe between 6.3% & 6.5% 5k, 6k and 7k RPM Between 7.7% and 7.8% Had to stop at 7k RPM as Police showed up, I was reported by security guy in H&M. Could someone provide me with figures I should be aiming at?
OK so need to make the mixture leaner as expected. How much should it be when it jumps to main jets from idle jets? Thx, Nelly.
Ah, thought you was on fuel injection.... 4% is still usually a good aim for idle on carbs, but you won't get an meaningful readings just holding the bike at a particular rpm at any other point. You need to load it up on a dyno. You're not going to get on mains just holding it at different rpm with no load.
Well some sparkplug/gas analyzer testing done. Moving the middle from 3rd on top to 2nd makes both spark plugs white, even the one that was soggy. Back to 3rd. Air screws were not evenly in so reset that, I started from scratch and am now at 4.2% at idle. Throttle response is better. At 3k rpm my ting mark aligns with case mark using strobe. Just above that and it moves to the right so it advances more and more with rpm. Sort out timing, I drill out bolt from can cover so can stop oil leak and dyno time.
You must be v carefull to where you take your samples from. If its the tailpipe you results will not be valid because most pipes join in the middle . The 749 assemetric (has one pipe per cylinder) ok may not joinlike 1098/738 etc but you get reversion in the can unless you can get in there by 2-3 feet Attach the co2 meter into the small factory sample pipes in each header. You can use a brake pipe nipple with 18th BSP pipe thread to attach c0 meter
CJS my measuring pipe is 25cm long so it was in by about 28cm in to "silencer". It was on monster. I will redo the test as it may explain why plugs are still white? How long does it take for plugs to change colour after making changes? One at start was soggy black, one dark brown. After moving needle from 3rd notch to 2nd both went white but at idle still about 7% on gas analyser. Then I moved needles back and it was better on the move. I used air screws to lean out the mixture but now plugs are all still white after about 5 - 6 miles. Manga it is H&M warehouse so closed after 1730 and I was on the road opposite side of it.
