Speedo CalibrationThe 2250 refers to engine rpm, not cable rpm. I believe Deez calculated that the cable rotates one full turn for four revolutions of the cranckshaft rotor. You may want to try hooking it up before installing the trim ring, and test it that way. The needles are a press fit, and will pry off. Sometimes they are stubborn, and will get distorted upon removel.
davomoto
wacky speedoBrewsky,
I had what sounds like the exact same problem as you...a speedo that would wander all over the dial and buzz like a V bomb. using the drill test it seemed to work fine, but installed and running was a different story. I dropped a few drips or dripped a few drops of 30wt into the cable insert at the base of the speedo, let 'er sit, and that took care of my trouble. Hope this helps. Mike You've lost me on the RPM, Davo..are you talking about the tach cable? The speedo face says "60 MPH = 2250 RPM" leading me to believe it's the cable speed and is there as a calibration formula. I don't have a tach on the Dream. My bezel trim ring was already cracked before disassembly, so repeated assembly won't be good for it, that's why I would like to calibrate it before clamping it back together. If my guess is correct, my drill maxed out at 1350 RPM should read 36 MPH on the speedo. Looks like recleaning and road test is in order before complete reassembly. 66 dream, 78 cb750k, 02fz1, 09 wing
Finally got around to calibrating my speedo after the second clean and re-lube job.
Steps: 1. Ride bike at constant speed (I used 50MPH) and check actual speed vs GPS or other known correctly calibrated speedo riding with you. (I used a hand held GPS zip tied to the steering damper 2. Note the difference. (When my speedo said 40MPH, my GPS indicated 50 MPH actual)..10 MPH off! 3. Dissamble the speedo. 4. Connect the bottom end of the speedo cable to a reversable drill, run the drill wide open (in reverse) and note the indicated speed on the speedo. (my speedo indicated 38 MPH with the drill running wide open) 5. Rotate the tab on the needle spring stop to either increase or decrease the tension on the spring. (since mine was reading low, I needed to decrease the spring tension) 6. Re-run the drill and see if the new max reading on the speedo is increased (or decreased) by the same amount as the original error. (My error was 10 MPH, so the new drill max reading should be 48MPH on the speedo instead of 38MPH.) This is a trial and error process. 7. Repeat 5 and 6 if necessary. 8. Reassemble and reinstall the speedo. When I rechecked the bike on the road against the GPS, it was dead on the money. Note that when choosing a "correct" speedometer to check against to begin with, the speedometer on most cars and motorcycles are at least 5 to 7 MPH off at 60 MPH even when new, so GPS is best to use. 66 dream, 78 cb750k, 02fz1, 09 wing
Hi,
Yes, this is the only way to do it, a GPS is the best measuring tool for speed anyway. The reason that most speedo's are not very accurate (a little too positive) is that the factory cannot be held responsible for speeding tickets. In the same way one could re-adjust the tachometer (but doing that you need a good calibrated tachometer) Jensen assembly of Japanese motorcycles requires great peace of mind (Pirsig)
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
