Tool Question (no, not what does 46 & 2 mean) Remote Tachometer

[Gordon in nc]

<snip> Have to give credit that with 5twins help diagnosing that I don't have the correct year carbs on the bike and with the carb guide written by him and Grizld1<snip>

robinc, glad to hear your not all oily now!!!!

YES.......we are SO lucky to have those kind of fellows around. I'm not working on an XS carb........it's on a 1993 and by that time they were thinking they should go ahead and move to EFI......the carb is very complicated...at least for me it is.

When I did my B model XS carbs.......first CV carbs I've messed with. This site had ALL the information to get the job done.....GREAT photos and narrative was written so you could follow along. My XS carbs came out fine....had to tweak them a bit (can't remember now what the problem was but 5twins had the answer) and they have worked flawlessly ever since.

The carb I'm working on now........I'm on another web site for it and information wise it's like night and day to this site.

Okay....gota get to work. Take care and keep warm.......spring is just around the corner. :O)

Your friend in NC, Gordon

 

[Gordon in nc]

Success!!!!!!! What a PIA carburetor. You can get an Amal "close enough" and do thousands of miles on it. But this puppy had to have EVERYTHING just right before it'd be happy. The TA100 is a WONDERFUL tool. So easy to use. Yes, a bit pricey but I have no regrets. Pick the number of cylinders and away it goes. Read the same on either plug wire and you just kept it close to them no need to hook anything up. The RPM's did jump around a bit but I expected that (and it was mentioned on here) but it didn't take long to tell what was going on. As per the manual I adjusted the air screw for max RPM then turned in the air screw in until there was a 50 RPM drop. It was only after all of that did the carb function like it should. Absolutely no hesitation off idle in gear......I'm as happy as a kid with a new red wagon....WITH a new puppy in it and I think it's ready for my daughter. She takes her Motorcycle Safety Course this weekend....and she's excited about it. An oil change, inspection and a tag and the bike is ready for her.

WELL......I still have to figure out how we're going to tell her mother......good thing I have nice dog lots.....hope they won't mind sharing.

Thanks for all the help.....take care.....spring is just around the corner. Gordon in NC

 

[weekendrider]

Grizld1 I've read your post over several times but it isn't turning on the light bulb. This is the way my ignition is wired.

I have the positive probe from the meter hooked up to the green wire post on the coil with 1 megaohm resister inline.
The neg probe is going to the neg battery post.

Set the meter to 4cyl setting and started the bike. The reading was steady-er 54-56 But the horn was yeep beeping. I pulled the probe out and with just the black probe hooked to the battery was getting a 36-38 reading. Touch the red probe back and it went back to 54-56 but no yeeping.
With these pictures can you show me what I'm doing wrong?

 

[grizld1]

Beeping I can take, but when things start yeeping--can't stand that, it's enough to put anybody up the wall. You have my heartfelt sympathy!

Seriously, as long as you've hooked up with the red probe on the signal side of the coil (green wire in your diagram) and the black probe on ground, you should be getting a signal; according to the Sperry manual, you're hooked up right. Where that 36-38 reading is coming from with the red probe removed I have no idea. You might try clipping the black probe to the cylinder head instead of the battery. I have plenty of experience installing electronic tachs, but the Sperry meter is as new to me as it is to you. Calibration issue? I dunno. Maybe 2M will chime in on this. I have the tank off my XS right now, and when I get the chance I'll hook up the remote fuel bottle and see if my meter acts like yours. But if that sucker yeeps at me--well, if threats don't work, the Big Friendly Hammer will.

 

[TwoManyXS1Bs]

The legacy documentation for the Sperry ADM-18A states that the input impedance is 10 MegOhm, so shouldn't need to add a 1 MegOhm resistor to your probe line.

Download the Sperry ADM-18A manual here (6th down on left):

http://www.sperryinstruments.com/en/resources/legacy

The long probe wiring and extension may be acting like an antenna. Try without the resistor and extension, clip the ground close to the ignition box's ground, keep the probe wiring away from sparkplug wiring...

 

[weekendrider]

2M I got rid of the all the extra. The black/neg probe is under the same screw as the ground wire. The red/positive wire is separated from any other.
The meter is still reacting with only the neg connected and when the pos is placed on the green wire coil post the reading doubles. If I dial a setting with more cylinders the numbers go down but the pattern is the same. Both probes read about double of what the single neg probe does. If i ground both probes the reading goes to zero's.

 

[TwoManyXS1Bs]

OK, next tricks.

Try the contact cleaner and trimpot wipe trick on one of the other pots while the meter is on and hooked up to your running bike. Maybe place a mirror on the bike so you can see the display while fiddling with the pot. Try this for both pots, but separately.

Try it on a points-type car, truck, tractor. The coil signal is a bit different on electronic ignitions as compared to points. I had to redesign the sensing front-end of my LED timing light circuit for DogBunny when he built one for his TCI bike.

Spurious readings when just the ground is hooked up may indicate a grounding issue of some type, or ultra sensitivity (on the red probe wire) to radiated emmissions, like solid-wire plug wires. Try that same thing on your car or truck, see what happens...

Edit: Waitaminit, looking at your video, you've got the meter's knob pointing to the right???

Edit2: Nevermind. I was thinking 'tach' was on the left, but that's dwell.
I think I'll paint the arrow on my meter, it's kinda hard to see...