Well I added 6 discs to the existing 8 discs........Waaaay too loud!  It didn't change the O2 readings at all.


Im seriously surprised,,

I would have thot adding 8 disks, which is exactly what I did, would have leaned it out. Im runnin the K&N slip in element, I Think , IIRC, a 152 main & I cant even guess at the pilot. But IM sure IM rich,

Charon wrote on 10/10/12 at 12:48:17:


Yes, I used a standard header pipe and intentionally mounted the sensor in a place that did not disturb the end of the pipe so you could bolt anything on that works with the stock header.  I would be willing to rent the pipe and sensor with a deposit......the only issues are how to keep the system from being on an indefinite loan and remaining in the public domain.  The system can be mounted in about an hour.  Any help in establishing a reasonable rental and depost amount are appreciated.

Gyrobob wrote on 10/11/12 at 05:43:11:


I am one that always believed that leaner mixtures burned hotter....as that is when exhaust valves, spark plug insulators and piston crowns get burned up.  It could be that it is not the heat doing the burning - it could be the left over O2 is burning those things.  In the old days of having 2 stroke motorcycles lean meant scored pistons....but that is probably a result of not having enough fuel/oil mixture to lubricate things adequately.

JOG.....No problem typing an answer.  My mother taught typing in a high school and I learned to type early.....and I can type almost as fast as I can think.

I think the big thing I learned is that we may all be trying jets that are too big, and maybe not moving the slide needle as much as we should.  I currently am running a 150 main and a 52.5 pilot, and I have 3 washers under the slide needle - but my slide needle has a clip and I have moved it to the third space from the bottom.  I just went for a ride and the gauge is showing I have a mixture of 12.7:1 at all throttle settings.  The only time it is leaner is when at idle as I can set the screw wherever I want it, and it goes lean when you close the throttle.  I just looked on the internet and the ideal mixture for power is 12.6:1, the mixture where there are equal parts air and fuel burned and nothing is left over is 14.7:1, and maximum fuel economy is 15.4:1.  I think at the 12.7:1 I am about perfect.......it might be nice to lean the cruise out just a tad for economy - but right now the engine runs smooooooth as silk and has great power and throttle response.

The O2 gauge allowed me to know exactly where I needed to make things richer or leaner.....and I avoided lots of trial and error.  And I am not experienced enough to know by ear exactly what rich sounds like......or maybe not even what lean sounds like.  I knew the surging my bike had just off throttle was lean......but it was an obvious problem.  How to fix it was not so obvious.

Dave wrote on 10/11/12 at 15:52:55:



Excellent work.  If only the factory would have been that precise!

One thing to consider.  Air:fuel ratio of the mixture at the instant it is ready to be burned in the combustion chamber will be different on a hot day compared to a cold day, at higher elevations compared to sea level, and on a cloudy day compared to a clear day because of the differences in humidity and pressure.  They will even vary a tenth or two depending on the exact blend of gas.



That said,..  

-- what you have done is to make the carb consistent at all throttle settings and flow rates.
-- you have given us all an appreciation for how the carb has to be several carbs all in one to properly handle high flow rates vs small flow rates, and wide open vs idle.

Quite an accomplishment.

I'd still like to see how all this effects cyl head temp and exhaust gas temp.

Dave wrote on 10/11/12 at 15:52:55:


This corresponds with what Cobra says about my C50 and I'm happy to see that.

Quote:



--Steve