Different cylinder timing with dual channel total loss

[McDog]

How accurate are the LED readings on a dual channed brain when checking the static timing?

1st cylinder is lighting up at 28 degrees advance but the 2nd cylinder is lighting up at 31 degrees. I seem to remember reading about some bad pickup plates out there that are not at 180 degrees. Is that probably my problem? Or is the LED not all that accurate and I should check the timing with a timing light and not worry about it?

 

[freestylegeek]

How accurate are the LED readings on a dual channed brain when checking the static timing?

1st cylinder is lighting up at 28 degrees advance but the 2nd cylinder is lighting up at 31 degrees. I seem to remember reading about some bad pickup plates out there that are not at 180 degrees. Is that probably my problem? Or is the LED not all that accurate and I should check the timing with a timing light and not worry about it?

Always check with a timing light. The LED while turning it over by hand is good for getting you in the ballpark, but you have to verify with a timing light. I had my timing set to 28º on the LED, but it showed 23º on the timing light.

 

[GIL]

Shane, left you a voicemail.

 

[SUPERTUNE]

Yes they can be off a little, also depends on how you are reading the degrees.
We use a dial indicator with a timing chart and we can really see how close it is in thousandths!
Drill out the pickups 1/32 bigger so you have a little slop then you can adjust them up and or down to get them even.
The MSD backing plates are a little too small on the O.D. and have some up and down slop and will change timing too, you can push it up and down also to help.
Older analog versions you needed to verify the timing with a timing light, but not needed with the muilti channel digital MSD TL, the led is very accurate when in the LED mode for setting timing. JUST DON"T FORGET TO SET IT BACK TO RUN MODE WHEN YOUR FINISHED SETTING THE TIMING!

 

[McDog]

Thanks Chuckie. I can always count on you for some total loss help. I am using the "marks on the case and marks on the flywheel" method and using a level to make sure my eye is in the same place every time. Hopefully this is the last peice of the puzzle for my build.

 

[augustaf]

I took an old analog plate and added hole/inserts 180 deg. from originals. was off by only 1.5 deg which I then corrected by shifting the pick up. look at my pic: I strongly suggest you glue down your wires if you want them to last more then a few months, seems the vibration can and will fracture the wires where they enter the p/u coil

 

[Pablo]

sounds like you don't need a machine shop. now finish this bastard. call in to work, fake sick, say you have an emergency,...whatever, just get done! John seconds that.

 

[GIL]

Shane, I was gonna tell u about the same thing Chuckie did. I slot my trigger plates to be able to get em even. I had the same deal with my RAD cover setup.

 

[Shifty]

I found the pickup mounting holes in the plate (at least mine) were drilled correctly at 180* appart. There was 3 degrees difference between the two pickups that I could not tune out by moving them (holes were not slotted). It turned out one of my pickups was just triggering at a different spot. I think the item was molded incorrectly at the plant.

 

[Watty]

If you turn the pickups around to get the pickup wires on one of the pickups to go straight through the hole in the pickup plate, then it can be out by up to five degrees. If you do turn the pickup on it's mount, you'd have to slot/open up it's mounting plate hole a fair bit to get the two cylinders even.

Every pickup plate I've seen has had the mounting holes machined perfectly, it's just the pickups themselves that differ...as in they are not symmetrical in thier molded housings. I'm yet to see perfect timing when just installing the two pickups on the plate straight from the box. Every total loss setup I've done has needed the pickups to be pushed around and have the holes opened up, so what you are seeing is normal.

 

[masterblaster]

watty
old thread,but good info..ive noticed this also,more timing from the rear cylinder in this case,how much movement are you creating opening the holes in order to get timing perfect between both pickups in most cases?

 

[Watty]

I pretty much just drill all 4 holes on the pickup base out bigger so you are able to adjust both enough to make the timing even. Also, the difference in timing can sometimes show an out of index crank, so if the timing differs a lot, it might be a good idea to get a degree wheen and a dial indicator and make sure the crank is ok first.

 

[masterblaster]

youve had a out of index crank and out of sync pickup,that would be a interesting trouble shooting day