Wilsons Sandbox

> want to spend the bucks on a Dyno Jetting run, or an exhaust analyzer run, > then jet by the plug condition. You have made a good start, but you'll be

in

> there a couple times before you finally find happiness. (Maybe not, you

might

> get lucky, most tuners I know usually take several shots before they

settle

> on a combination) > > Hope my personal experience helps you out. > > Jim

I've been "tuning" my DR650 as it was a rush job to get it running for Moab. I had been running 8 discs in the Trapp with a 145 Factory Jet main and 21/2 turns on the pilot, snorkel and screen pulled and a K & N. It was running decently but Toby detected some hesitation when he test rode it. I started by cutting the discs down to 4 as I wanted to get a quieter exhaust and improve the fuel mileage which is a tad below 40. I didn't expect that it would make that much of a difference (4 discs according to Trapp is like a stock muffler)...bike ran terrible, sputtering and choking over 40 mph. I assumed it was running rich. Rotated the carb and put a 142.5 and increased the discs to 12 (just for experiments sake)...now runs even and pulls hard throughout the range...but not quiet as much gusty as with the 145 and 8 discs...I decreased the pilot jet to 13/4 and am now getting a bunch of "popping" on deacceleration. The bike starts w/o fuel enricher so I suspect the needle is very aggressive even though it is in the middle notch. I have a dial-a-jet and that is probably the next step as you have to adjust the main on the leans side. The good news is that the DR is a lot easier to work on the KLR...the bad news is that the tank is still in the way of pulling the two plugs... Kurt

Jeff, Interesting in theory, but what I'd like to know is how much load (or stress or tension etc) is being placed on my KLR with different amounts of chain slack. As a baseline, we could use 20 hp at the rear wheel and chain slack at 0.5", 1.0", 1.5", ... through 3.0". It would also be instructive to know how much extra "load" is placed on the driveline system when the chain is too tight. In this example, let's assume that the rider momentarily backs off on the trottle & immediately resumes the original throttle position. You have your homework assignment. For extra credit, you can report on the increased forces when the rear wheel & sprocket alignment is off by 1/16". I'm looking forward to the figures. TIA Professor A9 Federal Way, Wa. [USA] ------------------------------------------------ --- "Jeffrey L. Walker" wrote:

> I actually learned the mathematical definition of "Jerkiness"

in my Machine Dynamics class last week. If you take the derivative of a position as a function of time, you get velocity. If you then take the derivative of velocity, you get acceleration, yeah? Well, if you then take another derivative of acceleration, you get "Jerk". So a jerk is the third derivative of position function. Its so simple. Its one of those things I always instinctively knew, but never thought of mathematically before. Of course we were using it in analyzing cam profiles. Interesting to me anyway.

> > Jeff

------------------------------ original message:

> > > > A chain that is too loose causes unnecessary jerkiness on the > > powetrain (chain, sprockets, clutch, transmission bearings, > > shafts & gears). These additonal loads lead to increased > > wear & shortened life of all these components. Proper chain > > maintenance (adjustment & lubrication) does wonders for > > extending chain & sprocket life. > >