nklr: gps precision

[Jim Cunningham]

Once you start it, can you keep it idling (at say 1500rpm) by holding the throttle open a bit? -----Original Message----- From: jbdrury@... [mailto:jbdrury@...] Sent: Wednesday, August 02, 2000 17:17 PM To: DSN_klr650@egroups.com Subject: [DSN_klr650] carb adjust/been sitting x 2 years I bought an 1988 KLR650 that has been sitting for 2 years. I can't get it to idle. I have: cleaned carb, cleaned jets, bought new battery, changed oil, changed air filter, replaced fuel line hoses, taken apart and put together carb several times. I have main jet screwed in all the way. I tried pilot jet screwed all the way in and also pilot jet backed off one full turn. The bike will start and die out if I try to let it idle. I have played with the idle adjust screw also. I am frustrated. Any suggestions? I am about to give up and declare defeat and take it in to the dealer for service but I really wanted to get this bike running on my own. Visit the KLR650 archives at http://www.listquest.com/lq/search.html?ln=klr650 Support Dual Sport News... dsneditor@... Let's keep this list SPAM free! Visit our site at http://www.egroups.com/group/DSN_klr650 To unsubscribe from this group, send an email to: DSN_klr650-unsubscribe@egroups.com

[Kurt Simpson]

sorry, I see the answer to my questions...open the pilot jet to 2 1/2 turns...

> -----Original Message----- > From: jbdrury@... [mailto:jbdrury@...] > Sent: Wednesday, August 02, 2000 5:17 PM > To: DSN_klr650@egroups.com > Subject: [DSN_klr650] carb adjust/been sitting x 2 years > > > I bought an 1988 KLR650 that has been sitting for 2 years. I can't > get it to idle. I have: cleaned carb, cleaned jets, bought new > battery, changed oil, changed air filter, replaced fuel line hoses, > taken apart and put together carb several times. I have main jet > screwed in all the way. I tried pilot jet screwed all the way in and > also pilot jet backed off one full turn. The bike will start and die > out if I try to let it idle. I have played with the idle adjust screw > also. I am frustrated. Any suggestions? I am about to give up and > declare defeat and take it in to the dealer for service but I really > wanted to get this bike running on my own. > > > > > Visit the KLR650 archives at > http://www.listquest.com/lq/search.html?ln=klr650 > Support Dual Sport News... dsneditor@... > Let's keep this list SPAM free! > > Visit our site at http://www.egroups.com/group/DSN_klr650 > To unsubscribe from this group, send an email to: > DSN_klr650-unsubscribe@egroups.com > > >

[Dreas Nielsen]

After launching more discussion and disagreement than I had expected to regarding the precision of GPS measurements of distance (or speed), I decided to just go out and measure it. Accordingly, this morning I marked 11 waypoints in succession, with the GPS fixed in one spot. The time between marking each waypoint was about 3 seconds. The GPS was seeing 5 to 6 satellites during this time. I then plotted the 11 points and their geographic centroid, and set out to find the average deviation of the measured points. I did this two ways, the first way (method A) assuming that the 11 positions were randomly distributed, and the second (method B) assuming that the 11 positions followed a continuous trajectory. (Visual examination of the spatial distribution of points could support either assumption.) By method A, I computed the average deviation of the points from the centroid, and by method B I computed the average deviation between successive waypoints. With method B, to account for the fact that it took me about 3 seconds to acquire each waypoint, and because I want a measure of the variation to be expected in one second, I first divided each of the successive deviations by 3. The results were that method A yielded an error estimate for a single point (average deviation) of 6.65 feet, and method B yielded an error estimate of 1.55 feet. To measure the distance traveled (e.g., in one second), the distance between two successive points must be computed, and the error about the locations of the individual points must be propagated to yield an error estimate for the distance. Thus, method A yields an error estimate for a computed distance (any distance measured between two points) of 9.4 feet, and method B yields a corresponding error estimate of 2.2 feet. If the distance calculation is made using two points whose positions are measured one second apart, and the GPS (motorcycle) travels 85 feet in that second (or 58 mph), then the relative errors in the distance measurement are 11% and 2.6%, respectively. The GPS might actually do better than either of these by measuring positions more frequently, or might seem to do better (in the speed display) by presenting a running average of the last few measurements. And for a continuous record of distance traveled, all of those little measured distances (e.g., 85 foot segments) have to be added up, and their errors propagated. If you string together enough little distances and propagate the errors, the relative error will decrease; for example, if you string together 30,600 intervals, the relative error at the end is about 0.01%. Dreas